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Table of Contents

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TECHNICAL PROGRAM

Held in conjunction with World GoldOctober 2-5, 2011

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GENERAL PLENARY: General Plenary I

Monday AM Room: Westmount/OutremontOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Cesar Inostroza, Rio Tinto Alcan

8:20 AM Introductory Comments

8:30 AMPresentation Title Currently Not Available: Jean Simon1; 1Rio Tinto, Primary Metal - North America Abstract currently not available.

8:55 AMGlobal Challenges of the Mining Industry: Chris Twigge-Molecey1; 1Hatch Global growth, particularly driven by China, is putting tremendous stress on the minerals and metals supply chain. Demand for urban infrastructure and housing, consumer goods and electronics requires materials that can only be derived from mining. A basic expectation for Canadian mining companies working around the world is to exceed the appropriate international safety, social and environmental norms and to properly engage with local stakeholders, while returning a suitable profit to shareholders.Managing risk associated with climate change, political instability and venal governments adds further challenges to the normal range of geological, technical, human and market risks. In his presentation “The mining Industry’s Global Challenge” Chris Twigge-Molecey will provide insight into the leadership and innovation being demonstrated by the Canadian Mining industry on this dynamic global landscape.

9:20 AM PlenaryThe Conference of Metallurgists - 50 Years Old: Fathi Habashi1; 1Laval University The year 2011 marks the 50th Anniversary of Conference of Metallurgists organized by the Metallurgical Society of CIM. The Metallurgical Society was originally the Metallurgy Division of CIM. The name change took place in Kingston at the Sixth Conference of Metallurgists in 1967, the same year that Canada celebrated its Centennial. The change of name reflected the growing stature of the organization. The recommendation to organize a Metallurgy Division emanated from a group of metallurgists, in the Ottawa Branch of CIM in September 1944. This was approved at the CIM Annual General Meeting in Québec City on April 18, 1945. The sponsors hoped “to enhance the influence of the Institute by providing a medium whereby metallurgical members could more readily exchange the results of their professional work and discuss problems arising therefrom”. This hope has certainly been fulfilled.

LIGHT METALS: Aluminium Production I

Monday AM Room: LachineOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Houshang Alamdari, Aluminium Research Centre - REGAL, Université Laval; Earle Chin, SNC-Lavalin

10:00 AMA Performanace Equation for Dry Scrubbers with Co-current Flow of Alumina and Hydrogen Fluoride: Edgar Dernedde1; 1Kroll International A few studies have indicated that the absorption of hydrogen fluoride on smelter alumina is determined by kinetic factors. However no comprehensive performance equation for dry scrubbers has been published in the literature. Experimental data from a pilot dry scrubber with co-current flow were compared with results from three kinetic models, which

were based either on the mechanism of absorption or film diffusion or pore diffusion. Both the HF concentration profile along the dry scrubber and the fluoride content of the alumina were predicted. All kinetic models were successfully fitted within the accuracy of the data. One kinetic model was considered suitable as a performance equation and was extended to include the recycle operation. Operating results of a few dry scrubbers with co-current flow were evaluated by means of the performance equation, which includes the effect of gas flows, fresh alumina feeds, HF inlet concentrations and the recycle ratio.

10:25 AMTowards Industrial Aluminum Spent Pot Lining Treatment with Complete End-Product Valorisation: Ghislain Hamel1; Nicolas-Alexandre Bouchard1; Raymond Breault1; Simon Leclerc1; Stéphane Poirier1; 1Rio Tinto Alcan The LCL&L process (Low Caustic Leaching & Liming) is a patented hydrometallurgical route developed by Rio Tinto Alcan (RTA) to economically process spent pot lining (SPL) generated by aluminum cells. The three resulting end-products (carbonaceous, fluorinated and caustic liquor) are inert and have valorization possibilities. An industrial size pilot plant located in Saguenay (Quebec) was inaugurated in mid-2008 to demonstrate and optimize the technology. This paper describes characteristics of the LCL&L process and the experience acquired by RTA since the plant’s start-up, including ramp-up capacity and technology challenges that were overcome. Possible end-products valorization methods are also presented. The carbonaceous end-product can be separated into carbon and brick rich fractions and used as either alternative fuel, reducing agents, or as raw material for third party processes. The development of a conversion process for the fluorinated end-product would allow its reuse as a substitute to fluorspar mineral for aluminum fluoride production. Finally concentrated caustic liquor is already valorized at the nearby RTA Vaudreuil alumina refinery.

10:50 AMPhysiochemical Properties of Cryolite-Silica Melts: Samira Sokhanvaran1; Mansoor Barati1; Sridevi Thomas1; 1University of Toronto High price of solar grade silicon caused by limited supply has become the bottlenecks of the photovoltaic industry to achieve its much anticipated growth. It is thus essential to develop a method for synthesis of solar silicon which is energy efficient and will deliver inexpensive feedstock material. As a promising approach, the electrodeposition of silicon from cryolite based electrolyte at relatively low temperature (1000°C), similar method to Hall–Heroult process for Al production has been investigated by different researchers. In spite of lots of this, the electro deposition of silicon production has not been commercialized yet. One of the main barriers is the lack of information on physiochemical properties of the electrolytes. Density and specific conductivity as two important properties were studied in this research. Data on dependence of electrical conductivity and density for cryolite–SiO2 melts will be presented for various compositions and temperatures.

11:15 AMMethodologies for Fingerprinting Sources of Dust in Aluminium Smelters: David Wong1; Nursiani Tjahyono1; Margaret Hyland1; 1University of Auckland Particulates represent a significant component of airborne emissions that are regulated in the primary aluminium smelting industry. Airborne particulates in the potrooms of these smelters, otherwise known as ‘potroom dust’, are of particular focus because they comprise one of the major sources of particulate emissions to the environment from smelters. With regulated limits for particulate emissions tightening over time, the industry faces two challenges: first to understand the major sources and mechanisms that generate potroom dust emissions, and secondly to determine what strategies or solutions can be implemented to manage these emission pathways. This paper presents the development of sampling and analysis methodologies that have allowed the fingerprinting of material sources of dust across a range of smelting technologies. The research has

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provided greater understanding on the overall compositional signature of dust present in the general aluminium smelting potroom. Particular focuses include: dust that is aerated within the potroom, dust that is settled on surfaces in the potroom, and the relation of these two forms of dust to material sources in the potroom. Such methodologies may also be applicable to other metallurgical industries. A case study is presented on how this methodology was used to identify the major sources of dust in a generic potroom, and how contributions from these sources varied as a function of location across a potroom.

MATERIALS - INNOVATIONS IN JOINING OF ADVANCED MATERIALS: Laser Welding and Processing

Monday AM Room: LongueuilOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Priti Wanjara, CNRC

10:00 AM KeynoteLaser Welding Technique for Titanium Alloys: T. Shariff1; Xinjin Cao2; R Chromik1; J. Gholipour2; P Wanjara2; J. Cuddy3; A. Birur3; 1Mcgill University; 2Institute for Aerospace Research; 3Standard Aero Limited Titanium alloys have found increasingly wide range of applications in aerospace, chemical, medical, sporting, power generation, oil and gas extraction industries mainly due to the low density, high mechanical property characteristics, biocompatibility, and excellent corrosion resistance. In the manufacturing routes of their finished products, welding has been a key technique used and always been a main concern requiring the stringent compliance to the well defined process. Conventionally, gas tungsten-arc (TIG), gas metal-arc (MIG), plasma arc, and electron beam welding processes have been used to weld titanium alloys. Nowadays, laser beam welding has provided great challenging applications for titanium alloys due to the low and precise heat input, deep and narrow fusion zone, small heat-affected zone, low thermal distortion and high productivity. At the NRC Institute for Aerospace Research, some R&D work has been undertaken for titanium alloys using laser beam welding process. These investigations have mainly concentrated on optimizing the welding process as well as understanding the fundamental process-structure-property relationships. In this invited keynote presentation, the research progresses obtained and the main issues encountered in laser welding of titanium alloys will be briefly summarized.

10:50 AMUse of Filler Wire for Laser Welding of Ti-6Al-4V: Abu Syed Humaun Kabir1; Xinjin Cao2; Mamoun Medraj1; Priti Wanjara2; Jonathan Cuddy3; Anand Birur3; 1Concordia University; 2National Research Council Canada; 3Standard Aero Limited Due to the high specific strength and excellent corrosion resistance, Ti-6Al-4V alloy has been widely applied in aerospace industries. In this study, Ti-6Al-4V alloy sheets with two thicknesses, 3.2-mm and 5.1-mm, were welded using a 4 kW high power Nd: YAG laser. Filler wire, matching in composition with the parent metal, was added to investigate gap tolerance for joint gaps of up to 0.6 mm. The joints were characterized in terms of the weld geometries, defects, microstructures, and mechanical properties. Fully penetrated joints were obtained up to a joint gap of 0.6 mm with no cracks. Underfill and porosity were identified as the two main defects in the weldment. Also, the porosity area was determined to increase with increasing joint gap. The microindentation hardness was maximum in the fusion zone and sharply decreased through the HAZ, where a hardness minimum was observed.

11:15 AMPotential of Laser Welding and Friction Stir Welding for Joining AA1100-16 Vol.% B4C Metal Matrix Composite: Junfeng Guo1; Patrick

Gougeon2; François Nadeau2; X. Grant Chen1; 1University of Quebec at Chicoutimi; 2National Research Council Canada This work illustrates the potential of two welding processes for joining AA1100-16vol.% B4C metal matrix composite: laser welding process using a 4 kW Nd:YAG laser and Friction Stir Welding. A comparison is made between these two welding techniques in terms of microstructure and mechanical properties of welded joints. A large amount of brittle needle-like phases, together with some residues of B4C particles were observed in the fusion zone of laser joints. The use of Ti filler can improve the microstructure and increase the joint efficiency from 63% to 75%. On the other hand, the friction stir welding process being a solid state welding technique does not lead to the formation of brittle intermetallic phases. In addition, the breakage of B4C particles and the grain refinement of the matrix were observed in the weld zone. Consequently, the FSW joints show much better mechanical properties than laser joints. Up to 100% joint efficiency can be achieved by FSW for annealed AA1100-16vol.% B4C materials.

NEW TECHNOLOGY IMPLEMENTATION IN METALLURGICAL PROCESSES: New Technology Review

Monday AM Room: Fontaine HOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Joël Kapusta, BBA

10:00 AMA Success Path from Process R&D to Commercial Plants: Kamal Adham1; Lawrence May2; Andrew Tohn1; 1Hatch Ltd.; 2Hazen Research, Inc. The path from process conception to commercial implementation poses significant technical, economic, and sometimes political challenges for every project team. Solving the technical challenges typically distinguishes successful projects from those that fail. Here, the authors provide an outline for technical success based on lessons learned from years of experience in process design and R&D. Challenges faced by new technology developers, with regard to design and definition, are described. Experience-based methods to avoid missteps are shared. Special emphasis is placed on the selection of viable unit operations, definition of known and unknown parameters, experimental screening of options, and piloting for scalable design information. Use of computational models to define, assist, and interpret the pilot operations and results are described. Furthermore, the value of active collaboration amongst the design, research, and owner teams is demonstrated.

10:25 AM KeynoteCreative Options for Development of New Metallurgical Processing Technologies: R Schonewille1; 1Xstrata Nickel One of the many challenges in developing new metallurgical processes is choosing the best option for validating process design parameters and establishing the process operating window. Historically this has been achieved by constructing pilot or demonstration plants of considerable size and complexity, to enable integrated operation of all key process units for a significant duration. While this would appear to be the best option for minimizing technical risk, it is often impractical from a perspective of cost, schedule, resources or bulk sample acquisition. Such an undertaking can even provide a false sense of security, as the optics of running a complete scaled-down version of a commercial plant suggest a high level of process understanding, regardless of the challenges encountered during operation. Xstrata Nickel has undertaken numerous process development and improvement projects over the past 15 years to support green field project development and continuous improvement in existing operations. The approaches used have included; computer simulation, cold flow modeling,

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construction of pilot test units in third party facilities, commercial plant referencing and the more conventional construction of integrated test plants. Regardless of the strategy employed, the keys to success have included; managing stakeholder expectations, involving the commercial plant design engineers in the planning stage, anticipating subsequent data and sample requirements and most importantly, constructing and operating complex demonstration plants only as a last resort. This paper provides examples of various process development approaches used by Xstrata Nickel and discusses the rationale specific to each project.

10:50 AM InvitedObtaining Maximum Value from Metallurgical Projects – Avoid Throwing It Away: George Eltringham1; 1tony Eltringham Consulting Operations downstream of mining and beneficiation are still being subjected to increasing scrutiny as highly capitalized projects have been either slow to achieve their targets or have actually failed to do so. Leaching and smelting projects have fundamentally high calls on capital and technology as reaction rates are increased and the capture and disposal of unwanted products are subjected to greater restrictions. Separating value from waste inherently becomes riskier as the purification of the desired product imposes greater demands on the process to produce benign wastes. When we superimpose on the chemistry of the project severe predictions of throughput rates, that bring in facets of manufacturing, we are introducing complexities that the records show are not handled well. This paper discusses some of the more common challenges that operators face and what methods are available and are likely to be successful in preventing the loss of value as projects are brought on-stream. This thinking needs to start much earlier and at greater intensity than our industry has normally chosen to employ.

11:15 AMKeynote: Implementing New Technology in Metallurgical Processes: Building Plants that Work: Bert Wasmund1; Nils Voermann1; Brady Haneman1; Jim Sarvinis1; Greg Sheehan1; 1HATCH Success in implementing new technology for metallurgical processes is not a foregone conclusion: This paper includes a survey of 23 new-technology based metallurgical plant start-ups, in which the authors have identified 7 successes, 9 difficult start-ups, and 7 failures. Success is defined not only as meeting the schedule and budget to mechanical completion; the key goal is a fast ramp up to the full design production level, with minimum plant and equipment modifications required after start-up. This paper sets out the key factors that underlie achievement of a quick production ramp up curve, as determined from the authors’ project experiences and a quantitative analysis of over twenty metallurgical plant start-ups, both pyro and hydro. Thorough test-work and pilot plants, plus appropriate scale-up to the full commercial plant, are key determinants of success in implementing new technology in metallurgical processes. Another critical factor is the number of new elements and their interactions. Project phasing is also particularly important for new technology projects, with appropriate review after each phase to develop a risk mitigation plan for the subsequent phase. New technology projects need committed champions to advance the project in the face of skeptics, but also require dispassionate and unbiased experts to ask the hard questions. As a project evolves, it is important to periodically question the appropriateness of assumptions, as well as re-assess the relevance and completeness of data from test-work / pilot plants / industrial analogues. Sufficient human and financial resources are required to complete the often arduous implementation phase. During the ramp-up period, the operation generates little positive cash flow; however, significant expertise and capital are required for the de-bottlenecking projects that are typically necessary to reach the plant’s design output level.

WASTE RECYCLING IN MINERAL AND METALLURGICAL INDUSTRIES: Metal Recycling I

Monday AM Room: VerdunOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Michael Sudbury, Consultant

10:00 AMReview of Lead Recycling Technology: R. Prengaman1; Abbas Mirza1; Timothy Ellis1; 1RSR Technologies, Inc. Recycled lead, i.e. material produced by the recycling of lead-acid batteries, has become the primary source of lead in much of the world. This has been important to the recycled lead industry as other uses have dwindled, e.g. lead based pigments, chemicals, fuel additives, solders and CRT glasses. Presently, battery manufacturing accounts for greater than 85% of lead consumption worldwide while recycled lead accounts for approximately the same market share of lead supply. Battery manufacturing and production of recycled lead are intimately coupled. In 2007, of all the industrial base metals, lead from lead-acid batteries had the highest recycling rate in North America at greater than 95%. In this paper we will review some of the processes and technologies used in a modern lead acid battery recycling facility, and how recycled lead has become the material of choice for battery construction through the development of a recovery and refining process that exceeds the industry requirements. We will also briefly review an advanced air emissions treatment system in a modern lead recycling plant that demonstrates the feasibility of a new maximum available control technology (MACT) for secondary lead smelters.

10:25 AM KeynoteOverview of Waste Processing & Recycling of Nonferrous Metals in Metallurgical Industries in China: Xueyi Guo1; 1Central South University The total production of nonferrous metals in China is 31.35 million tons in 2010 including aluminum 16.2 million tons, copper 4.57million tons, lead 4.2 million tons, zinc 5.16 million tons. It ranks first in the world for the past nine years and is expected to reach 42 million tons in 2015. Large quantities of waste residues, waste water and dust are produced every year in the production of nonferrous metals. These secondary resources are renewable, not only contain abundant valuable metals which can be recycled by metallurgical processing, but also could eliminate the pollution to the environment. In this paper, the status quo of the nonferrous metals recycling in metallurgical industries in China was summarized and the future development of waste processing and resource recycling was also prospected.

10:50 AMPhysical Separation Process for Recovering Tantalum Capacitors from Electronic Devices Mounted on Printed Circuit Boards: Tatsuya Oki1; 1National Institute of Advanced Industrial Science and Technology Several tantalum capacitors can be seen on printed circuit boards of electronic devices such as personal computers, servers, communication instruments,and other commercial calculators. These capacitors contain a considerable quantity of expensive metal tantalum. Some impact breakers can detach and liberate a large number of various types of electron devices from printed circuit boards. However, there are few reports on the recovery of specific devices from these electron devices mixtures. First in this study, size and density distribution of the liberated electron devices were investigated. Then, tantalum capacitors were recovered from the other electron devices using size separation and pneumatic gravity concentration methods. More than 70 per cent of Newton’s separation efficiency can be obtained for electron devices liberated from several types of printed circuit boards used in this study. And, the results of separation examinations suggested a possibility to separate other types of electron devices such as chip resistors and other kinds of capacitors by this simple physical separation process.

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11:15 AMCopper and Tantalum Recovery from Printed Circuit Board: Toyohisa Fujita1; HIroyuki Ono2; Gjergj Dodbiba3; 1The University of Tokyo; 2 ; 3 PCBs for personal computer (PC) and household appliance were crushed by water explosion to liberate mounted parts from PCBs. More parts were liberated from PCB for PC composed of epoxy resin than from PCB for household appliance composed of phenol resin. In an attempt to raise the copper grade of Printed Circuit board (PCB) by removing other components, carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under nitrogen atmosphere at 1073K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment. On the other hand, tantalum sintered bodies were separated from molded resins by heat treatment at 723, or 773K in air and screening of 0.5mm. Silicon was removed and a tantalum fraction with a grade of 70% was obtained after separation.

11:40 AMEffect of Electricity Mix and Ore Grade on the Carbon Footprint of Chilean Cathodic Copper: Claudio Zaror1; Claudia Peña2; Mauricio Bustamante2; Mabel Vega1; 1University of Concepcion; 2CIMM The goal of this paper is to present the carbon footprint of Chilean cathodic copper, as a function of the electricity generation mix, ore grade, and process efficiency. In Chile, 99.7% of electricity is generated by two interconnected grids, namely, the Northern (SING) and Southern (SIC) systems, featuring different technology mixes. Indeed, thermoelectric generation contributes with more 99% of electricity generated at SING, as compared with less than 50% at SIC. Thus, the carbon footprint at SING and SIC, is in the order of 1.1 and 0.4 ton CO2/MWh, respectively. Since electricity is a key input in cathodic copper production, the geographical location of processing facilities is expected to have a significant effect on GHG emissions associated to cathodic copper. Typically, Chilean cathodic copper from oxide ores feature an average electricity consumption of 2 MWh/ton, and this value increases as ore grade, and process efficiency decrease. Results show that the carbon foot-print of cathodic copper is in the range 2.2 ? 4.3 ton CO2/ton copper. GHG emissions from fuel consumption in mining operations account for around 1.1-1.6 ton CO2/ton copper, whereas the rest is mostly associated with electricity generation in thermoelectric plants. The implications of this findings to energy and environmental management are discussed.

WORLD GOLD: Keynote I

Monday AM Room: Hampstead / Cote St. LucOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Guy Deschenes, CANMET

10:00 AM KeynoteGold Space from a Producer’s Prospective: Peter Kinver1; 1Barrick Gold Abstract currently not available.

WORLD GOLD: Mineralogy of Precious Metals I

Monday AM Room: Hampstead / Cote St. LucOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: B. Staunton, AMIRA

10:50 AMThe Mineralogy and Predictive Metallurgy of Major Types of Gold Ores: Joe Zhou1; 1 Based on the mineralogical characteristics and mineral processing techniques required, gold ores can be classified into 12 major types, including gold placers, quartz vein-lode ores, oxidized ores, silver-rich ores, iron oxide copper gold ores, porphyry copper gold ores, iron sulphide ores, arsenic sulphide ores, antimony sulphide ores, bismuth sulphide ores, telluride ores and carbonaceous sulphide ores. The bulk mineralogy and gold mineralogy of each ore type is different and may have a significant impact on ore processing and metal extraction. Generally, gold in placers, quartz vein gold ores and oxidized ores often occurs as coarse- and fine-grained particles and can be recovered by gravity and/or direct cyanide leaching. Gold in sulphide ores is commonly associated with sulphide minerals in which gold occurs as tiny inclusions or submicroscopic gold and fine grinding is often required prior to cyanide leaching. In Sb-, Bi- and Te-bearing gold ores, gold often occurs as aurostibite, maldonite and gold tellurides which may cause processing problems due to their slow-dissolving kinetics during cyanidation. In carbonaceous sulphide ores, gold occurs mainly as submicroscopic particles within the structure of sulphide minerals such as pyrite and arsenopyrite. These sulphide minerals are usually insoluble and impervious in cyanide solution, making the gold refractory. This paper will present the mineralogy of gold in each of the major types of gold ores and discuss the potential impact of gold mineralogy on gold metallurgy. Case studies will be provided where applicable.

11:15 AMApplications of Microbeam Analytical Techniques in Gold Deportment Studies: Stamen Dimov1; Brian Hart1; 1Surface Science Western, University of Western Ontario Accurate, detailed information about the gold content and distribution within a feed ore sample or process stream products is of crucial importance for identifying potential losses and optimizing the gold recovery process. The implementation of advanced micro-beam analytical techniques such as Dynamic Secondary Ion Mass Spectrometry (D-SIMS), Time-of- Flight Mass Secondary Ion Mass Spectrometry (TOF-SIMS) and Time-of-Flight Laser Ionization Mass Spectrometry (TOF-RIMS) for the needs of the mineral processing industry has resulted in the development of new protocols to accurately identify and assess the carriers and forms of gold in mineral samples. Major advantages of these techniques are related to their ability to directly analyze individual mineral particles, provide quantitative analysis with detection limits in the low ppm/ppb concentration range and as well as to image the gold distribution within the mineral grains. This paper will outline the various analytical instruments and techniques involved in characterizing all carriers and forms of gold in mineral samples which have been developed and established at Surface Science Western (SSW) In refractory ores a substantial part of the gold content may be present as a sub-microscopic component within the mineral matrices of the various carriers. This sub-microscopic gold can be of solid solution or colloidal (size < 0.5µm) type and can not be identified by the means of optical microscopy. The Dynamic SIMS is a benchmark technique for quantitative analysis of sub-microscopic gold with detection limits in the range of 0.2ppm and imaging capabilities with spatial resolution of 1 µm. By analyzing large number of individual grains from different mineral phases, it is possible to achieve an accurate quantitative estimate of sub-microscopic gold content in the various mineral phases within the sample.

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11:40 AMAn Alternative Automated Electron Beam Technology for Gold Characterization: Denise Doerr1; Daniel Lopez1; Ronel Kappes1; Timothy Drake2; 1Newmont Mining Corporation; 2ASPEX Corporation Automated scanning electron microscopy has been widely used in recent years for gold and other precious metals characterization. However, application of this technology is resource intensive and in most instances needs specialized technical personnel to process the samples and information. Newmont Metallurgical Services (NMS) has recently acquired a personal SEM (PSEMTM) from ASPEX. The PSEMTM offers some significant benefits/improvements in sample preparation and sample processing time. NMS and ASPEX have been working together to develop an approach utilizing this technology for the minerals processing industry and specifically for gold characterization.

WORLD GOLD: Plant Practice and Projects I

Monday AM Room: Mont RoyalOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Bryn Harris, McGill University

10:50 AMPlant Expansions and Leach/CIL Optimization at IAMGOLD’S Rosebel Operation in Suriname: Chris Fleming1; Mohamed Ourriban2; Pierre Pelletier2; 1SGS; 2IAMGOLD The IAMGOLD Rosebel operation in Suriname is a large tonnage, low grade operation comprising an open pit mine, crushing, SAG/ball mill grinding, gravity separation, cyanidation and CIL. Production at the Rosebel plant commenced in February 2004 at a design treatment rate of 4.8 Mt/a, and by January 2009 throughput had been increased by 150% to 12 Mt/a, through a series of mill expansions in 2005, 2007 and 2008. Moreover, mill feed was changing from predominantly soft saprolitic ore (BWI = 2.6 kWh/t) to predominantly transition and hard rock ore during this time (BWI = 4.7 and 13.1 kWh/t, respectively). The expansion was achieved through the addition of a primary crusher to handle the hard rock, pebble crushing capabilities in the SAG circuit, an additional ball mill and more leach/CIL tanks. The amount of gold recovered per annum has more than doubled in six years as a result of the expansions, and plant operating conditions in the leach/CIL circuit were adjusted to accommodate the higher throughput. The carbon advance rate was increased, but this resulted in shorter residence times in acid washing, elution and regeneration, and the recycling of poorly regenerated carbon meant gold losses to the CIL tails were unacceptably high at times. A survey of the CIL plant was therefore undertaken in early 2010 to determine whether the plant performance could be improved by changing the operating conditions in the existing plant, or whether new equipment would have to be bought and installed. A simple approach was adopted by IAMGOLD, which involved the development of a mathematical model of the Rosebel CIL plant that simulated and accurately predicted the plant performance.

11:15 AMAgnico-Eagle Laronde Plant: Metallurgical Challenges Present and Future: Jean Cayouette1; Paul Blatter1; 1Aginco-Eagle Mine - Laronde Division The Laronde mill was commissioned in 1988 and has been treating the Laronde Penna ore since 2000. The Laronde plant, situated in the Abitibi region of Quebec, has experienced mill expansions to accommodate 7500 mtpd and to recover gold and silver as well as important amounts of base metals (Cu, Zn, Pb). Ten sequential metallurgical and environmental processes are responsible for metals recovery and process viability. Over 200,000 ounces of gold, 4,5 million ounces of silver, 7000 tonnes of copper, and 78,000 tonnes of zinc are produced annually. In 2008, the Goldex plant in Val-d?Or began trucking high grade (35-45 g/t Au) sulphide concentrate

for gold extraction at a newly constructed treatment plant, increasing gold output at Laronde site by 40,000 ounces. In 2009, the high gold grade Lapa ore processing facilities were annexed to the Laronde plant increasing output by 120,000 ounces of gold. Laronde, Goldex and Lapa productions are forecasted until 2023, 2018 and 2015 respectively, with known reserves of each mine. Today, up to 140 permanent employees run and optimise ore processing facilities at the Laronde mine. This new Laronde operation plant has intrinsic intricacies inherent in a large and varied operation. The paper will outline the metallurgical highlights, challenges, and future outlook related to the treatment of each ore type (Laronde, Goldex ?sulphide concentrate? and Lapa).

11:40 AMContinuous Improvement Initiatives at the Newmont Ghana Gold Limited Ahafo Operations: Johan van Huyssteen1; 1Newmont Ghana Gold Limited Newmont Ghana Gold Limited’s Ahafo Operation has matured from its project ramp up stage into steady state operations after three years of continuous operation. Management focus has shifted from addressing construction and commissioning problems to optimization and improvement. This focus change has coincided with the introduction by Newmont of a continuous improvement (CI) program across the company. This paper will focus on the application of CI principles at the Ahafo Gold Processing Facility with particular reference to the following case studies: As an example of a black belt project, the mine to mill initiative, including optimization of blasting patterns in the pit, improvement of blending on the ROM pad and implementation of an expert system and particle size analyser. As examples of green belt projects: optimization of the elution circuit, reduction in plant down time through the improvement of maintenance planning and reduction of re-work, As examples of lean belt projects: optimization of the primary crusher gap settin, developing of a management operating system to manage process plant contractors. Each of the above projects could be presented as a technical report in itself. However, the paper will focus on the before and after situation for each project and the financial benefits that were realised for the company through the application of CI principles. Reference will also be made to the CI projects planned for the immediate future, including: reduction of gold in solution inventory in the milling circuit (black belt), implementation of oxygen addition into the leaching circuit to enhance leaching rate and reduce cyanide consumption (green belt), improving tool room management (lean belt)

WORLD GOLD: Strategic Mine Planning I

Monday AM Room: Fontaine DOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Roussos Dimitrakopoulos, McGill University

10:50 AM KeynoteKinross Mine Planning Best Practice: Rob Henderson1; Chris Turek1; 1Kinross Gold Corporation Mine planning is the foundation of value for a mining company. Good mine planning requires solid understanding of the ore body, rigorous standards and processes, robust and useful information technology and skilled people. Life of mine planning is key to identifying strategic direction for any mine and short range mine planning is key to delivering forecast and budget expectations. Mine planning at Kinross has been identified as a critical success factor and initiatives are being prepared to improve the quality of our plans and to build bench strength in our teams. The Kinross Way for Mine Planning (KWMP) has been developed and implemented to establish the standards to ensure a strong business foundation. This paper briefly describes the process used to develop the KWMP and presents a selection of mine planning best practice initiatives at Kinross mines.

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11:15 AMSemafo’s Mana Operations Enterprise Optimization: Patrick Moryoussef2; Richard Peevers1; Gerald Whittle3; 1Ausenco Vector/Whittle Consulting; 2Semafo Inc.; 3Whittle Consulting Whittle Consulting’s Enterprise Optimization methodology was successfully applied for Semafo’s Mana operations. The Mana operations consist of several open pits and a proposed underground mine in Burkino Faso, West Africa. The surface-minable ore is relatively shallow and the pits are long and linear. The underground operations as currently envisioned will consist of a stoping operation accessed by two ramps from surface. Power is a concern at this property due to local power being produced solely by diesel generator. This became one of the key optimization constraints. Other important parameters were the mining and processing rate, underground configuration and cutover elevation, and Semafo’s enviable position of ongoing reserve increases.

11:40 AMModelling Geological Uncertainty in Mining Using Multiple-Point Statistics: Peter Jones1; Ian Douglas1; Arja Jewbali1; 1Newmont Mining Traditional, geostatistical based, categorical modelling techniques can often fail to reproduce the complex non-linear geological features seen in mineral deposits. This lack of reproduction can be attributed to the reliance of traditional methods on second-order spatial statistics i.e., the variogram. Multiple-Point Statistics (MPS) is an emerging technique, which can be used to generate multiple, geologically realistic, realizations of data that displays complex non-linear features. MPS uses a conceptual model of the geology, called a Training Image (TI), to infer these high-order spatial relationships. The multiple realizations allow for an assessment of the geologic uncertainty, which can be further combined with grade simulations at afford a more complete picture of the true uncertainty of a mineral deposit. Results of a bench height study and drill-hole spacing study for the Apensu deposit in Ghana, comparing a MPS approach to a traditional, geostatistical based, methodology are presented.

LIGHT METALS: Aluminium Production II

Monday PM Room: LachineOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Martin Désilets, Aluminium Research Centre - REGAL, Université Sherbrooke; Lyes Hacini, Rion Tinto Alcan, ARDC

2:00 PMDevelopment of Representative Assembly for the Fabrication of Cold Ramming Paste Samples at Laboratory: Sakineh Orangi1; Donald Picard1; Houshang Alamdari1; Donald Ziegler2; Mario Fafard1; 1NSERC/Alcoa Industrial Research Chair MACE3 and Aluminium Research Centre-REGAL, Laval University; 2Alcoa, Primary Metals A representative sample of ramming paste from a peripheral seam in an aluminium electrolysis cell was taken in order to develop a process to fabricate ramming paste samples in the laboratory. To this end, paste material was compacted in multilayers in a mould designed to be representative of peripheral seams in Alcoa’s smelters. The density distribution in the representative sample was measured ranging from 1.51-1.76 g/cm3. The density range obtained by the proposed methodology in laboratory is 1.47-1.77 g/cm3. The results demonstrate that the proposed fabrication method adequately duplicates paste density from the cell for both one and two layer compaction. Finally, preliminary results related to the compressive strength and Young’s modulus of laboratory samples were obtained at various temperatures and are presented in this paper.

2:25 PMTime Delay of the Temperature Measurements in High Temperature Furnace: Marc-André Marois1; Martin Désilets1; Marcel Lacroix1; 1Université de Sherbrooke This paper proposes an improved temporal stability condition for the implementation of an inverse heat transfer method for predicting the time-varying bank thickness of the phase change protective bank inside a high temperature furnace. The direct problem is handled with the enthalpy method. The inverse method rests on the Adjoint Problem and the Conjugate Gradient Method. It is shown that the temporal stability condition for the inverse phase change problem relies on the time delay of the temperature measurements. Results indicate that this time delay is proportional to the heat diffusion time including heat diffusion through the mushy zone.

2:50 PMModeling and Simulation of Green Anode Forming Process: Hicham Chaouki1; Stéphane Thibodeau1; Houshang Alamdari1; Donald Ziegler1; Kamran Azari1; Mario Fafard1; 1Laval university The aim of this work is to simulate the forming process of a green anode. For this purpose, a nonlinear compressible viscoelastic constitutive law is presented. The concept of natural reference configuration is considered [1]. Within an isothermal thermodynamic framework, a Helmholtz free energy is proposed to take into account the nonlinear compressible deformation process occurring between natural reference configuration and actual configuration. A dissipation potential is introduced in order to characterize the irreversible aspects of compaction process. Thus, the behavior law is formulated trough two equations: 1) an expression of Cauchy stress tensor and 2) a differential equation characterizing the natural reference configuration evolution. Material parameters are assumed to be functions of bulk density. This allows capturing the micro-mechanical phenomena within the chosen macroscopic approach. An experimental study based on uniaxial simple and cyclic compression tests is carried out in order to characterize mechanical behavior of the anode paste.A user’s material VUMAT subroutine for finite elements dynamic explicit analysis has been developed and implemented in ABAQUS software. To evaluate the model predictive capability, the following numerical simulations were performed: 1) uniaxial simple and cyclic compression tests and 2) compaction forming process of anode paste. Simulation results show that the behavior law reproduces the experimental trends for compression tests and gives interesting physical responses for the compaction simulations. This constitutes a first step toward making a benchmark with experimental results on forming process of anode paste.References [1] Koneru.et al, 2008. A thermo mechanical framework for modeling the compaction of asphalt mixes, Mechanics of Materials, 40, 846-864.

3:15 PMTesting the In Situ Aluminium Cell Control with the Dyna/Marc Cell Simulator: Marc Dupuis1; Michael Schneller2; 1GéniSim Inc; 2 Recently, a new approach to controlling alumina feeding in a H.H. cell has been proposed [1,2,3]. This new approach, called In Situ aluminium cell control, is based on a correlation between the slope of the cell voltage during a no feed observation period and the dissolved alumina concentration in the bath. Once the dissolved alumina concentration has been estimated, a primary calibration surface uniquely relating the dissolved alumina concentration and the anode-cathode-distance (ACD) to the cell voltage is used to estimate the cell ACD. Once both the alumina concentration and the ACD have been estimated at the end of the observation period, a PID controller can be used to regulate the rate of alumina feeding using only the cell voltage to estimate the error between the estimated dissolved alumina concentration and a target value. The In Situ aluminium cell control algorithm has now been tested with the Dyna/Marc [4,5,6] cell simulator demonstrating that it should be possible to control a H.H. cell in this manner with less variation in the dissolved alumina concentration and other process variables producing a prediction of improved cell current efficiency.

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3:55 PMEffects of Microstructural Characteristics on Anode Reactivity: Francois Chevarin1; Houshang Alamdari1; Julien Lauzon-Gauthier1; Kamran Azari1; Mario Fafard1; Carl Duchesne1; Donald Ziegler2; 1Laval University; 2Alcoa Canada Primary Metals The reaction of O2 with the carbon anode is considered as the main parasitic chemical reaction affecting Hall-Heroult process anodes. The current study aims at investigating the influence of the microstructure of baked anode on its overconsumption. Samples were removed from different positions of an industrial anode. Density, porosity, LC and BET specific surface area were measured. The anode reactivity was evaluated based on the weight losses for the samples resulting from the reaction of anode with air at 550°C after 7h. The essential parameters determined to control the air reactivity are closed porosity, LC and pores with a pore entrance radius of 1.5, 8.5 and 12 µm. The knowledge of effects of these parameters allows better understanding of the reactivity of anodes and consequently reduction of their overconsumption in electrolysis bath.

4:20 PMX-Ray Microtomography Analysis of Aluminum Electrolysis Cathodes: Martin Lebeuf1; Marc-André Coulombe1; Gervais Soucy1; Bénédicte Allard2; 1Université de Sherbrooke; 2Carbone Savoie The phenomena occurring in the cathode and at the cathode surface of aluminum electrolysis cells are very important in regards to cathode voltage drop and cathode wear. In the current study, laboratory-scale aluminum electrolysis cell cathodes were analyzed by X-ray microtomography. This technique allows an excellent visualization of the distribution of different substances, if their respective x-ray attenuation coefficients are different enough. In the current case, the important difference in the mean atomic number between cryolitic bath and graphitic carbon results in good contrasts. The volumetric bath penetration profile, porosity and additives distribution in the cathode were thus obtained. Furthermore, metallic impurities and bath heterogeneities were observed at the cathode surface. Observations were also made with Scanning Electron Microscopy - Energy Dispersive Spectroscopy (SEM-EDS).

4:45 PMSome Hypotheses Concerning Cathode Wear in Aluminium Reduction Cells: Asbjorn Solheim1; 1SINTEF The service life for aluminium reduction cells is often limited by the cathode carbon, due to preferential wear along the periphery of the cell leading to the so-called “W” wear pattern. The reason for this preferential wear is not well understood. Carbon may dissolve into the aluminium pool and disappear by ordinary mass transfer across boundary layers at the cathode, at the metal-bath interface, and at the anode or gas bubbles. This can explain the average wear rate, but not the characteristic wear pattern. Two additional mechanisms for cathode wear are suggested in the present paper; 1) non-stationary dissolution of aluminium carbide into a layer of sludge that periodically forms and disappears, and 2) electrochemical formation and dissolution of aluminium carbide within an aluminium carbide layer containing bath-filled pores. The latter mechanism may be related to the high local current density at the periphery of the cathode.

5:10 PMCathode Wear Investigations in a Laboratory Test Cell: Kati Tschöpe1; Anne Støre2; Stein Rørvik2; Egil Skybakmoen2; Arne Ratvik1; Tor Grande1; 1NTNU; 2SINTEF Cathode wear has become an increasing challenge in the aluminum industry due to the use of more graphitized materials. Today, there exist no standard laboratory methods for measuring cathode wear where different commercial materials can be ranked. The typical average wear rate in an electrolysis cell is quite small (approx. 2 cm/year) but it is considerably higher in parts of the cell. The aim of this work was to design a test method where the wear could be accelerated compared to commercial electrolysis cells. It was focused on polarized tests where the cathode is exposed to electrolyte, which gives higher aluminium carbide solubility. Different set-ups were tested, and the most promising design was investigated

intensively. The cathode materials were thoroughly characterized by optical and electron microscopy and by image analysis, in order to measure the surface topography before and after the wear test.

MATERIALS - INNOVATIONS IN JOINING OF ADVANCED MATERIALS: Welding Processes Involving Hot Deformation / Arc Welding Processes

Monday PM Room: LongueuilOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Xinjin Cao, CNRC; Jidong Kang, McMaster University

2:00 PMTools For Friction Stir Welding and Processing: A Review: Yi-Nan Zhang1; Xinjin Cao1; Maxime Guerin1; Simon Larose1; Priti Wanjara1; 1Aerospace Manufacturing Technology Centre, NRC Institute for Aerospace Research Friction Stir Welding (FSW) is a novel “green” manufacturing technique due to its energy efficiency and environmental friendliness. This solid-state joining process involves a rotating tool consisting of a shoulder and/or a probe. The shoulder applies a downward pressure to the work-piece surface, constrains the plasticized material around the probe, generates heat through the friction and causes plastic deformation in a relatively thin layer under the bottom surface of the shoulder. The rotating probe mainly drags along, plasticizes, and mixes the adjacent material in the stir zone, creating a joint without fusion. Friction Stir Processing (FSP), a variant of FSW, has been developed to manufacture composites, locally eliminate casting defects, refine microstructure and/or improve the associated mechanical and physical properties including strength, ductility, fatigue, creep, formability and corrosion resistance. However, major challenges such as tool design and wear currently limit the use of FSW/P for manufacturing applications, particularly for high melting temperature or high strength alloys. In this review, the FSW/P tools are briefly summarized in terms of the tool types, shapes, dimensions, materials and wear behaviors.

2:25 PMInfluence of Welding Parameters on Stir Zone microstructures during Friction Stir Welding of Magnesium Alloys: S. Borle1; H. Izadi1; Adrian Gerlich1; 1University of Alberta The microstructural features produced in friction stir welded AZ31, AZ80 and AZ91 alloys are examined when different welding parameters are applied. The microstructures primarily consist of a-Mg grains with a-Mg + Mg17Al12 colonies, however melted films of Mg17Al12 are produced in AZ91 alloy when high rotation speeds are applied. When the rotation speeds are slow, or the travel speeds are fast the Mg17Al12 were incorporated into the stir zone, however they do not exhibit an elongated lamellar morphology associated with melted films. In the case of AZ80, the extruded base material contains a smaller fraction of Mg17Al12 and few of these phases are observed in the stir zones. The results are explained based on the dissolution rate and melting temperatures of Mg17Al12 controlling the overall morophology and fraction of phases in the stir zone.

2:50 PMEffect of Heat Treatment on Linear Friction Welded Ti-5553: Elvi Dalgaard1; Priti Wanjara2; Javad Gholipour2; Xinjin Cao2; Anand Birur3; Jonathan Cuddy2; John Jonas1; 1McGill University; 2Aerospace Manufacturing Technology Centre, Institute for Aerospace Research, National Research Council Canada; 3Standard Aero Limited Linear friction welded near-ß titanium alloy Ti-5Al-5V-5Mo-3Cr was subjected to pre- and post- weld heat treatments in order to mitigate a phase depletion in the weld zone (WZ) and thermomechanically affected zone (TMAZ). Samples were evaluated for mechanical property restoration

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using micro-hardness testing and were examined microscopically using electron backscatter diffraction (EBSD) methods to determine the phase distribution. While the pre-weld heat treatments had no significant effect on the phases observed in the welded structure, the post-weld heat treatments were instrumental in restoring the a phase fraction necessary and the strength of the starting (heat-treated) material.

3:15 PMPressure Welding Solid State: Role of Hot Deformation: Hugh McQueen1; 1Concordia University Pressure welding is a solid state joining technique that depends on bringing the parts into sufficiently close contact that inter-atomic bonds are achieved. Pressing is more effective at elevated temperatures where plastic flow causes the asperities to collapse; improved application conditions are derived from hot-work research to clarify temperature and strain rate dependence of hot strength and ductility. The substructure evolution systematically studied in hot working to determine dynamic recovery or recrystallization is applied to clarifying that developed in welding. The various processes are affected differently by work-piece geometry and final shape requirements. In addition to pre-cleaning of the surfaces, the plastic flow helps disperse the remaining oxide layers as was originally exemplified in blacksmith hot forging of layered sword blades and in bell/die welding of wrought iron tubes. The presentation critically compares the utility for various materials and configurations of simple pressure, ultrasonic application, diffusion, explosive, rotary and linear friction and friction-stir processes. Diffusion bonding (primarily Ti) with light cleaning, low pressure, little distortion in protective furnace atmosphere contrasts strongly with the heavy upsetting in friction welding, or complex alloy mingling and substructure variations in friction stir joints.

3:55 PMThe Effects of Submerged Arc Welding (SAW) Waveform Variables on Productivity and HAZ Characteristics, for Single and Tandem Electrode Welds: Joel Pepin1; Hani Henein2; Douglas Ivey2; Chris Penniston3; Laurie Collins4; Douglas Boyd5; 1AITF; 2Dept. of Chemical & Materials Engineering, University of Alberta; 3Transcanada Pipeline Ltd.; 4Evraz Inc. NA; 5Dept. of Mechanical & Materials Engineering, Queens University High deposition, quality, and repeatability are just three of the characteristics of submerged arc welding (SAW) that make it an attractive welding process for producing pipes from microalloyed linepipe steels. Direct current electrode positive (DCEP) is the most common SAW polarity, due to good arc stability, adequate bead penetration, and availability of welding equipment. For higher deposition rates, one can use direct current electrode negative (DCEN) polarity, though this requires specialized wire/flux combinations, and it results in reduced bead penetration. Traditional sinusoidal alternating current (which cycles polarity rapidly between DCEP and DCEN) has reduced duration at peak current at either polarity, and significant periods of time at low voltage values. These two issues respectively result in reduced productivity and arc stability.New inverter power sources address both issues through the use of square-wave alternating currents, which provide maximum duration at peak current and minimal time durations at low voltage. Such power sources also allow the welding operator to manipulate waveform variables (such as balance, offset, and frequency), providing greater control of deposition rates and penetration depth. This provides an opportunity to optimize welding waveforms for specific applications.When welding microalloyed steels, it is critical to optimize the balance of penetration and high deposition rates, to minimize the number of weld passes while still achieving good

heat affected zone microstructures. A series of bead-on-plate welds were performed on microalloyed steel, to provide a greater understanding of the effects (and extent of the effects) that waveform manipulation has on welding deposition rates, penetration profiles, and heat affected zone properties. Both the effects of single electrode and tandem electrode welds will be presented. The mechanical properties, hardness, and toughness, of the heat affected zones were measured for different welding variables and will be presented.

4:20 PMProcess Engineering for the Freeforming of Al-based Components Using CSC-MIG Welding: Sean Brophy1; David Heard1; Mathieu Brochu1; 1McGill University Controlled Short Circuit – Metal Inert Gas (CSC-MIG) welding is a process that can be referred as a “Cold Welding” technology. The CSC process is based on accurate control of the welding wire position, thus the mandatory requirement for the automation of the process. One of the main advantages of the CSC-MIG process is the rapid solidification of the deposited material, resulting in weldments displaying low porosity contents, and enabling the joining of thin sheet materials. These characteristics render this process an ideal one for freeforming of components, where rapid solidification would be efficacious. This presentation will focus on the progress made towards the freeforming of Al-based components in the NAIN laboratory at McGill University. The relationship between the filler metal used, freeforming (deposition) parameters, resulting microstructure and mechanical properties will be presented.

4:45 PMStudy On the Quality of Friction Stir Welds Made by a Robot: Michel Guillot1; Yousef Imani1; 1Laval University Friction stir welding is a solid state joining process that is often used for joining aluminum alloys. Robotic implementation of FSW especially using existing heavy duty robots presents a strong potential for complex 3D assemblies in many industries. Although high capacity robots have been used for years, the implementation of FSW on these robots is relatively recent. Despite the fact that robots involve lacks of stiffness, positioning inaccuracies and require more adapted control algorithms especially for 3D joints, their application still requires proper setting of many process parameters like the speed and feed of the tool, the plunging depth and setting forces, the tool geometry and attack angle. Accordingly, this paper proposes first a brief overview of the robot, a Fanuc M900 of 700kg of payload, and FSW head. The complete experimental set-up is introduced as well as acceptable robot settings and force control algorithms for the FSW needs. Secondly, sets of experiments made on 1.52 and 2.54 mm thick AA 6061-T6 plates are carried out with linear and circular joints using several parameters to optimize the weld strength. These include the rotational speed in the range of 700-1800 rpm, the welding speed in the range of 0.3-1.5 m/min and the attack angle between 1 and 4 degrees. The weld quality is checked with surface appearance and the microstructure of the cross section of the joints and by use of mechanical tests such as bending, tensile and hardness measurements. Linear joints obtained from robotic FSW have been compared to similar joints produced by a CNC machine. Overall, the results have shown that it is possible to make linear and circular defect free FSW joints with good mechanical and microstructural quality using an industrial robot.

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NEW TECHNOLOGY IMPLEMENTATION IN METALLURGICAL PROCESSES: New Technology Implementation

Monday PM Room: Fontaine HOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Pascal Coursol, Alouette

2:00 PMAn Advance in Nickel Laterite Dust Processing at PT Inco: Anchal Samtani1; Angaa Luckita2; Richard Jones2; Jafri Syarifuddin2; Roimon Barus2; Jeffrey Donald2; 1Vale Base Metals Technology Development Ltd.; 2PT International Nickel Indonesia Tbk In conventional RK-EF laterite nickel processing, management of dust continues to be problematic. A large proportional of the material flowing through the kilns represents recycled dust, typically around 15%. More efficient processing of dust represents an opportunity for energy efficiency, increased production and productivity. PT Inco, in partnership with Vale Base Metals Technology Development (VBMTD), has successfully developed and implemented a novel flowsheet enhancement that capitalizes on these opportunities. Dust released by the kiln off gas is captured and recycled by injecting it into the main burner of the kiln at the calcine discharge point. The dust then joins the calcine, while the dusting rate of the kiln is unchanged. The present work describes the technology, the process through which it was developed and summarizes the lessons learned. A key conclusion is that successful new technology development requires a multi-disciplinary team involving R&D, study management, engineering consultants, project implementation management, process technology and operations.

2:25 PMEmpowering Operations and Maintenance through Wireless: Neil Freeman1; Soroush Amidi1; David Fisk2; 1Honeywell; 2Matrikon Wireless technologies are permeating the mining and metals industry and enabling a myriad of benefits. With standards such as IEEE 802.11 for wireless devices and ISA100.11a for wireless field instruments protecting their investments, customers look to benefit from the cost and flexibility offered by wireless devices. Using wireless field instruments, plants are eliminating the costs associated with wired system by 50-70 percent and using these savings to install more field instruments which used smartly enables them to optimize their processes efficiency and equipment reliability. Wireless also empowers a mobile workforce by allowing them to have access to key process and maintenance data directly from the field. This paper describes how wireless can help operations and maintenance personnel to be more effective. Three case studies, illustrating how the mining and metal industry are taking advantage of the technology today, are presented: - Optimisation of the water recovery process using wireless - Field operations improvement with wireless handhelds - Improving fleet maintenance through wireless mobile equipment management Finally the paper will conclude with an examination of some of the future technologies that will be enabled through wireless.

2:50 PMMonitoring Refractory Linings in Operating Furnaces by Acousto Ultrasonic-Echo Technique: Afshin Sadri1; Pawel Gebski1; Koorosh Mirkhani1; Wai-lai Ying1; 1HATCH The campaign life of an industrial metallurgical vessels strongly relies on the quality and quantity of the refractory lining. An operating furnace or converter refractory lining can be assessed either by thermal modeling or by acousto ultrasonic-echo (AU-E) technique or a combination. AU-E is a Non-Destructive Testing (NDT) stress wave propagation technique that has been utilized on a wide variety of smelting vessels for over 12 years with good success. AU-E can determine the thickness of remaining refractory lining, estimate the thickness of build-up or accretion, detect and locate

metal penetration and impregnation into the lining, and identify hydrated or cracked areas of refractory. This paper details the AU-E principles, equipment and recent improvements to the data analysis to further improve speed and accuracy. In addition, the paper discusses the AU-E accuracy and limitations through a diverse and vast array of practical examples including a comparison with thermal modeling and physical measurements.

3:15 PMOptibar Technology Successfully Implemented in Copper Electrowinning: The Myth is Fading: Eduardo Wiechmann1; Guillermo Vidal1; Florentino Muñoz2; Cristian Castro2; 1Optibar Ltd.; 2Barrick Gold Corporation Zaldívar Mining Company Different authors and publications indicate that Optibar Segmented Intercell Bars cause a remarkable distortion in the distribution of the current in a cell group. However, these results were based in inaccurate computer based models and do not represent the technology. During the last trimester of 2010, a 92 cells circuit from Barrick Zaldívar EW plant was implemented with Optibar Segmented Intercell Bars. The technology was incorporated progressively without disrupting the plant production. Depending on operational conditions, this led to a 2 to 4% current efficiency increase and 3 to 5% specific energy consumption reduction. By October 2011, 40,000 tons of copper will be produced with the technology.

3:55 PMDesign of the New Lihir Gold Pressure Oxidation Autoclave: Michael Collins1; A. Hasenbank1; B. Hewitt2; 1Sherritt Technologies; 2Newcrest Mining Limited Newcrest Mining Limited, originally as Lihir Gold, has operated a pressure oxidation plant for the recovery of gold from refractory ore since 1997. The mine and gold plant are located on Lihir Island in Papua New Guinea. Design of the original pressure oxidation circuit was based on the results of pilot plant tests conducted by Sherritt Technologies in Fort Saskatchewan. Following a decision to expand the plant in 2008, Lihir Gold contracted Sherritt to design a new autoclave. The design exercise utilized the original pilot plant test results, commercial process results at Lihir, and an understanding of advances in autoclave technology since the original plant was built. The new Lihir autoclave will be the largest pressure oxidation autoclave in the world. Mechanical challenges encountered in the design of this new vessel are described in this paper.

4:20 PMCobalt from Slag- Lessons in Transition from Laboratory to Industry: Arthur Barnes1; Rodney Jones2; 1Xstrata Process Support; 2Mintek Anglovaal Minerals acquired the Nkana dump from ZCCM in 1998 and embarked on an ambitious project to pioneer the recovery of cobalt from slag using DC smelting technology. Anglovaal Research Laboratories performed initial pioneering smelting tests in a 250 kW DC furnace over a 3-year period before engaging Mintek for three piloting campaigns at the 1.5 MW level. Mintek had previously developed a reductive smelting process, patented in 1995, using a DC arc furnace for the recovery of cobalt from slags. The results of the pilot-plant test campaigns were used as the basis for engineering the commercial 40 MW operation installed at Chambishi Metals plc in Zambia in 2001. This paper traces the development of understanding of the metallurgical fundamentals ultimately used to predict furnace performance, reviews some of the extreme technical challenges faced, how solutions were identified and highlights some of the critical issues identified during piloting and how these impacted both positively and negatively on the final commercial operation.

4:45 PMCopper EW Processes: State of the Art in Optimizing Current Density Distribution: Guillermo Vidal1; Eduardo Wiechmann1; Cristian Castro2; 1Optibar Ltd.; 2Barrick Gold Corporation Zaldívar Mining Company In copper EW plants the optimal current density setpoint depends on the electrolyte composition and temperature. However, conventional plants operate with large standard deviations. A value of 14% with current densities offsets up to ±50% is typical. For worst, during opencircuit or

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shortcircuit events this variation can be from -100% to +200%. Naturally, energy consumption and copper quality are compromised. Several devices have been successfully employed to reduce set point deviations. Last developments include; Optibar Segmented Intercell Bars, Outotec Electrodes Arranging Method and NTC Selective Electrodeposition Enhancers. This paper researches and compares these technologies. It is shown that short circuits can be effectively reduced in occurrence and magnitude. Moreover, 80% of the electrodes can be forced to operate within ±10% of the set point. The specific energy consumption is reduced from 2,000 KW per Ton to values close to 1,900 KW per Ton.

5:10 PMImplementation of Magnetic Conditioning in Two Stages of a Sequential Cu-Zn Flotation Separation: Barry Lumsden1; Jodi Wilding2; 1Ausmetec Pty Ltd; 2Jaguar Metals The implementation of new technology to mineral separation operations requires rigorous testing to confirm the technology?s technical and economic benefit. The Jaguar Mine owned by Jabiru Metals is located in Western Australia and sequentially separates a copper concentrate and then a zinc concentrate. Fine grinding (80%of zinc in tail is

WASTE RECYCLING IN MINERAL AND METALLURGICAL INDUSTRIES: Metal Recycling II

Monday PM Room: La SalleOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Michael Sudbury, Consultant

2:00 PMThe Characteristics of Electrolytic Refining of Tin Soldering Scrap Material in Hydrochloric Acid Solutions: Gergo Rimaszeki1; Tibor Kulcsar1; Tamas Kekesi1; 1University of Miskolc The efficient purification of soldering waste material can be achieved in a single operational step by the electrolytic refining in pure hydrochloric acid – tin-chloride media. The complex formation of the ionic species may offer a beneficial level of natural inhibition. Using the PCR (periodic current reversal) technology, is efficient in affecting the morphology of the cathodic deposit. In order to optimize the process, the investigation of the solution stability and the electrode reactions is essential. The natural tendency of the Sn(II) oxidation and precipitation can be overcome by properly controlling the concentration of the main components and the ratio of Sn(IV)/Sn(II) in the electrolyte solution. Polarization curves were obtained for different concentrations tin and hydrochloric acid. Conclusions referring to the electrode reaction were derived from the overvoltage - current plots. The morphology of the deposit can be correlated with the exchange current density, also determined from the polarization curves. The cathodic current efficiency and the morphology of deposited metal are effected by the distribution of tin species and the principal electrolysis parameters.

2:25 PMVanadium and Molybdenum Recovery from Industrial Wastes Using Cybber Ion Exchange Resins: Dmitry Kipper1; Vadim Korovin2; Yuriy Shestak2; Alexey Tikhonov1; Alexey Olifirenko1; 1NVK“Syntez”; 2N. Polyakov Institute for Geotechnical Mechanics at National Academy of Sciences of Ukraine The present paper deals with vanadium and molybdenum sorption from industrial wastes and intermediate processing products using Cybber macroporous strong- and weak-base anionites. Regularities of vanadium and molybdenum recovery by Cybber anion-exchange resins as well as desorption processes were studied in static and dynamic modes; their efficiency was demonstrated for that purposes. The results of the work may be used while designing technologies for complex processing of both ores and industrial wastes containing vanadium and molybdenum.

2:50 PMDezincing Galvanized Coated Steel Scrap by Using Sulfuric Acid: Luciana Cerqueira Souza Solimani1; Mônica Caetano de Lima1; Marco Quintela1; 1Usiminas Galvanized steel scrap is recycled to BOF converters where zinc escapes from the bath and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contain high iron content, it could be recycled, but due to its zinc content, it is disposed in landfills. In this study techniques were evaluated for zinc layer removal from scrap by sulfuric acid leaching. The effects of coating weight,temperature, time and sulfuric acid concentration were evaluated for three different galvanized scrap. The results showed that the behavior of each galvanized scrap was different. Nevertheless zinc removal efficiency was more than 80% with low dissolved iron in the leached solution.

3:15 PMVanadium Recovery from LD Converter Slag by Means of Heterotrophic Bacteria: S.M.J. Mirazimi1; Fereshteh Rashchi1; 1University of Tehran Recovery of vanadium from LD (Linz-Donawits) converter slag was evaluated by means of microbial leaching. Vanadium leaching was performed in two stages. In the first stage, the bacteria were grown in a culture medium and in the second stage; vanadium containing slag was added to the metabolites produced by bacteria. Bioleaching was performed using heterotrophic bacteria Pseudomonas Putida. Control tests without bacteria inoculation were also performed and the results were compared with bioleaching outcomes. Optimal conditions for the bioleaching of vanadium containing slag were determined.

WASTE RECYCLING IN MINERAL AND METALLURGICAL INDUSTRIES: Remediation. Characterization

Monday PM Room: VerdunOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Janice Zinck, CANMET; Stephanie Brienne, Teck Metals

2:00 PMAn Integrated Approach for Heavy Metal Remediation Using Sorbents Synthesized from Waste Residues: Yi Wai Chiang1; Johan Martens1; Boudewijn Meesschaert1; 1Katholieke Universiteit Leuven Mining and metallurgical activities have induced historical soil and groundwater pollution by heavy metals in many areas in Europe. Geochemical weathering processes acting upon the metallurgical wastes initiate the process of transporting these anthropogenic heavy metal stems from the contaminated areas to the environment. Therefore, the contaminated sites themselves are only the beginning of toxic contaminant release; toxic substances can follow environmental pathways and accumulate in environmental sinks. Sediments at the bottom of rivers are such environmental sinks for toxic substances. The redistribution of heavy metals by means of solute transport mechanisms can adversely affect water resources and endanger the health of surrounding ecosystems and human populations. Cost effective and ecological remediation of these sites is important to ensure the sustainable future of the metal industry in Europe. The widely diverse contamination sources in larger catchment areas for mining wastes usually produce a mixture of contaminants, which is more difficult to treat than an industrial waste. Often, traditional remediation techniques are economically unacceptable because of the large volume of contaminated materials to be treated. In such cases, the concept of in-situ soil amendment can provide both cost-effective and durable solutions. Immobilization, stabilization, solidification, and other forms of long term, self-containing barriers can help controlling the mobilization and biological availability of critical contaminants. Adsorbents are important products for contaminated site remediation. The detoxification mechanism mainly

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comes from their sorption properties, i.e. affinity for contaminant solutes, and/or ion exchange capacity. Once adsorbed, contaminants can become permanently stabilized within an operating window (pH, temperature, dilution extent). The aim of this study is to immobilize heavy metal pollution in north Belgium region due to historical metallurgical activities, in particular, As, Cd, Pb and Zinc with both commercially available (Iron (hydro)oxides, Hydroxyapatite and natural Zeolites) and in-house made synthetic absorbents (synthetic Zeolite and WTRs).

2:25 PMThe Effects of Thiocyanate Loading and Incubation Temperature on the Thiocyanate Degradation Ability of a Mixed Microbial Population: Andries van Zyl1; Sue Harrison1; Rob van Hille1; 1University of Cape Town The BIOX® process uses a combination of iron and sulphur oxidising microorganisms to liberate pyrite/arsenopyrite occluded gold prior to recovery by cyanidation and CIP. The reaction between cyanide and residual sulphur species results in the formation of a complex matrix containing thiocyanate (SCN < 1500mg/L) and residual cyanide (CN < 70mg/L). The BIOX® culture is inhibited by thiocyanate (> 1mg/L), precluding the recycling of tailings water up-stream of the bioleaching circuit. The drive toward water recycling and the desire to be zero-discharge has necessitated on-site treatment. The activated sludge tailings effluent remediation (ASTER) process was developed to facilitate water recovery and treat waste water (to SCN < 1mg/L) for disposal. Driven by the desire to commercialise and export the ASTER technology, research has been conducted to characterise operating window, composition and tolerance of the microbial consortium and thiocyanate degradation kinetics. The investigated temperature- and thiocyanate concentration ranges were 15-40°C and 60-1500mg/L respectively. Batch data showed SCN degradation rates to range between 12-60mg/L/h at initial SCN concentrations of 60-1500mg/L at 27°C. Linear SCN degradation rates were observed, following an initial adaptation period of approximately 10h. SCN degradation rates were reduced at 15°C and 40°C. Individual species were isolated using classical microbiological techniques. Pure culture kinetic data is being obtained as a function of substrate loading, dilution rate and temperature. Integration of these data, coupled with microbial ecology investigations will provide the necessary information to develop a predictive performance model.

2:50 PMFactors Affecting the Start-up, Operation and Decline of a Laboratory-Based Passive Treatment System for Selenium and Sulfate Removal: Parissa Mirjafari1; Luke Moger2; Ron Martel2; Susan A. Baldwin1; 1University of British Columbia; 2Mount Polley Mining Corporation Mine drainage contains metals and sulfate, which may be toxic to aquatic life at certain concentrations and should be removed to acceptable levels before release of any drainage to the environment. One method for treating mine drainage is passive treatment, which is increasing in popularity due to lower construction and operating costs. This method is based on the activity of sulfate reducing bacteria (SRB) respiring on sulfate while using fermentation products from decomposing complex organic materials. The product of this biological process is hydrogen sulfide, which reacts with metals in mine drainage and precipitates them as metal sulfides. However, in practice passive treatment systems are not always effective, reducing the reliability of this approach. In this study, a mixture of hay, cow manure and wood chips was tested in continuous flow experiments for efficacy at sustainable treatment of sulfate and selenium containing water from a mine tailings pond. Factors that contributed to a decline in performance included lowering of the pH due to acids leaching out of the organics, re-oxidation of sulfide back to sulfate and a reduction in dissolved organic compounds over time. In this paper we describe methods to overcome these problems so that treatment is more reliable.

3:15 PMThe Behaviour of As(III) and As(V) during the Precipitation of Alunite at 98ºC: Alba Sunyer1; John Dutrizac2; 1University of Barcelona; 2CANMET The factors affecting the precipitation of arsenic-free alunite (KAl3(SO4)2(OH)6) were investigated in a series of laboratory experiments. Although the amount of alunite precipitated increased with increasing retention time, temperature, solution pH and the concentrations of Al(SO4)1.5 or K2SO4, the composition of the products remained nearly constant. The preferred conditions identified for the precipitation of arsenic-free alunite were then used to assess the behaviour As(III) and As(V) during alunite precipitation at 98oC. Increasing additions of As(III), as NaAsO2 or As2O3, resulted in a slight increase in the amount of precipitate formed at pH 2.80. However, X-ray diffraction analysis showed all the precipitates to be alunite, and <0.2% As(III) was detected in the products. In contrast, increasing additions of As(V), as KH2AsO4 or As2O5, resulted in significant increases in the amount of precipitate formed at pH 2.80 or 3.00. Furthermore, the arsenate (AsO4

3-) contents of the precipitates increased up to 15%, and the sulphate contents decreased, as the As(V) concentration of the synthesis solution increased from 0 to 9 g/L. X-ray diffraction analysis of the products detected only alunite, but there was a progressive expansion of the alunite cell with increasing arsenate content. The implication is that arsenate substitutes for sulphate in the alunite structure. Preliminary observations on the environmental stability of the arsenate-bearing alunite using the TCLP protocol gave solubilities <0.4 mg/L from a precipitate containing 8.5% AsO4 and 7.8 mg/L from a product containing 19.5% AsO4. Thus, it appears that alunites containing less than ~10% AsO4 would be an acceptable vehicle for the disposal of arsenic from hydrometallurgical processing solutions.

3:55 PMThe Application of Advanced Characterization Techniques to Industrial Waste Removal Procedure: Nicolas Geoffroy1; Suzie Poulin1; George Demopoulos2; 1Ecole Polytechnique; 2McGill University Most metallurgical industries generate toxic waste that must be treated prior to being released to the environment. However, in a lot of cases, the waste materials are poorly characterized or the analytical results are not well interpreted. These shortcomings often result in the development of inefficient industrial procedures, thus causing economic waste and difficulty meeting environmental regulations. Fortunately, a wide range of analytical techniques are available to guide researchers and engineers into making sound process development decisions. In this work, an industrial selenium and mercury removal process is used as an example to illustrate the application of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (PXRD) on solid waste. Furthermore, samples of analytical results are presented and interpreted and the modifications to the industrial process that resulted are explained. Finally, a brief description of the advantages and limitations of the aforementioned analytical techniques is given with an emphasis on industrial solid waste material.

4:20 PMCharacterization and Reduction of Filter Dusts in the Liquid Phase: Gerald Schneeberger1; Stefan Steinlechner1; Jürgen Antrekowitsch1; 1University of Leoben The recycling of steel mill dusts is getting more and more important in future. The costs and requirements of land filling are rising and companies are interested in new recycling strategies. The rising of sustainability hand in hand with the high rate of valuable metals in these residues supports new research activities on the recycling sector. Especially zinc but also iron and lead are economical factors due to the treatment of steel mill dusts. This paper gives a small overview of fundamental studies concerning the chemical and physical composition of these dusts. Furthermore aggregates for the reduction of these dusts in the liquid phase are introduced and compared. The Flash-Reactor, the TBRC-Technology (Top Blown Rotary

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Converter) and submerged arc furnaces and there use for melting and treatment of these dusts are in the center of interest of this paper. The final conclusion gives an overview of possibilities for reduction of filter dusts in the liquid phase.

4:45 PMCharacterisation of Sulphide Oxidation in a Passive Acid Rock Drainage (ARD) Treatment System: Neehal Mooruth1; Robert van Hille1; 1University of Cape Town Acid rock drainage (ARD) is a significant problem associated with the commercial exploitation of sulphide minerals. Remediation is typically through active chemical treatment (lime dosing), although active and passive biological systems are receiving increasing attention. In water scarce regions, such as South Africa, the sulphate salinity in addition to acidity and heavy metal load is a concern. A demonstration scale plant based on the IMPI (Integrated Managed PassIve treatment) process has been constructed at a coal mine in South Africa. The sulphate reduction components have operated successfully, but the sulphide oxidation reactor, which relies on the formation of a floating sulphur biofilm, has not. The research involved a robust characterisation of the system using purpose-built laboratory scale (2.5m x 0.1m x 0.15m, 25L liquid volume) linear flow channel reactors (LFCRs). The work focussed on the hydrodynamics, sulphide oxidation kinetics and the microbial community structure. An oxygen requirement model, based on reaction stoichiometry and mass transfer kinetics, was developed to determine the required interfacial surface area for different volumetric loading rates. A comprehensive hydrodynamic tracer study was conducted to accurately describe the flow patterns within the reactor. The laminar flow and significant vertical stratification has important implications for reactor operation. The LFCRs were fed continuously with the effluent from two sulphate reducing degrading packed bed reactors (DPBRs), with a sulphide concentration ranging from 100?220mg/L. A 90% reduction and > 75% conversion to elemental sulphur was achieved at a hydraulic residence time of 5 days.

WORLD GOLD: Geology I

Monday PM Room: Fontaine EOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: G. Kirkham, Consultant

3:15 PMStatus of “Invisible” Gold: History and Analytical Methodology: Louis Cabri1; 1Cabri Consulting Inc. The earliest account of gold occurring “invisibly” in sulphides was by Bürg (1930, 1935) and its significance in mineral processing was discussed by Haycock (1937); both long before routine use of SEM, EPMA, and application of more specialized characterization methodology such as micro-PIXE, SIMS, LA-ICPMS, XANES, 197Au Mössbauer spectroscopy, and TEM. Boyle (1979) concluded that it is more probable that gold is present in a finely divided (colloidal?), often submicroscopic state (<0.1 µm). Interestingly, this size limit was also similar to that suggested by Haycock (1937) based on optical microscopy. Prior to 1986 there was no proof of chemically-bound gold until appearance of reports by Marion et al. and Wagner et al. (1986).Today, we have abundant proof of the occurrence of gold in sulphides in concentrations not readily visible optically or by SEM, which can occur either at the atomic level (chemically-bound) or down to nm-size particles of native gold. We may refer to both types of occurrence as “invisible” or “sub-microscopic” gold. Determination between chemically-bound and fine particulate gold requires detailed characterization using techniques such as XANES, 197Au Mössbauer spectroscopy, XPS, and TEM, which is complicated for many reasons. Factors making characterization challenging include (a) common heterogeneity of gold distribution, (b) extrapolation from

very high magnifications up to grain- and sample-size, (c) quantification of measurements/images, and (d) common presence of both types of gold in a single grain. Present-day methodologies for characterizing invisible gold will be reviewed, together with a personal view of best practices and pitfalls to avoid.

3:55 PMAn Investigation of Refractory Gold Distribution & Chemistry in Pyrite & Chalcopyrite: Jeffrey Warner1; Jeffrey Cutler1; Allen Pratt2; 1Canadian Light Source Inc.; 2CANMET-MMSL Synchrotron radiation microbeam methods and other techniques were used to map the spatial distribution and chemical speciation of gold and arsenic in pyrite and chalcopyrite from a porphyry copper deposit. Sample mineralogy and mineral chemistry were examined in polished grain mounts prepared from a sulphide concentrate containing gold bearing pyrite and chalcopyrite using optical microscopy, electron microprobe analysis (EPMA) and backscattered electron imaging (BEI). Imaging results showed that the pyrite and chalcopyrite particles were featureless and pristine with very few discontinuities. In some instances the pyrite particles had noticeable overgrowths that appeared as rinds in BEI. EPMA major and trace element analysis (>100 ppm As, Se, Ni, etc) showed that the pyrite and chalcopyrite had the expected major element compositions and surprisingly few chemical impurities. Secondary ion mass spectroscopy (SIMS) depth profiles indicated that both the pyrite and chalcopyrite contained gold with an approximate average concentration of 5 ppm, and that pyrite had an approximate average As concentration of 6 ppm. For both pyrite and chalcopyrite the depth profile data and ion images showed the gold occurring as micrometer to sub-micrometer sized particles and that these particles were dispersed throughout the matrix of each mineral. For pyrite the SIMS depth profile data and ion images showed a positive correlation between Au and As. For pyrite with overgrowths, the overgrowths showed As enrichment and in general a negative correlation with Au. Synchrotron X-ray Fluorescence (XRF) microprobe and x-ray absorption near edge structure (XANES) spectroscopy results from the Au L3-edge and As K-edge will be discussed in the context of results obtained from the electron and ion methods.

4:20 PMStructural Characterization of Orogenic Gold Deposits. A Case Study: Rosebel Gold Mine, Suriname, Guiana Shield: Caroline Daoust1; Gabriel Voicu1; Bjarne Westin1; 1Iamgold Orogenic gold deposits represent a major class of deposits that are found in various rock types of various ages. Those deposits show a strong structural control that usually complicates their interpretation at the regional and deposit scales. The Rosebel Gold district located in Surinam (South America) is hosted in a Paleoproterozoic greenstone belt of the Guiana Shield, and has been recently classified as one of those orogenic gold deposits. The gold district comprises eight distinct deposits located along three different structural trends and within different rock types. The mineralization is undeformed and shows a strong structural control characteristic of orogenic gold deposits. All the deposits of the Rosebel Gold district have been subject to a detailed structural analysis that has led to the elaboration of a new structural model for the whole gold district, which is now differing considerably from the previous models. This characterization had direct implications at three different scales. 1- While the older models were considering some areas of the property as gold-barren, the new structural model has led to recent exploration campaigns which have revealed positive results. 2- At the deposit scale, the comprehension of the various vein systems and of the folding of the host rocks has helped the establishment of optimized drilling campaigns. 3- At the mining scale, the comprehension of the architecture of the veins helps for the elaboration of optimized mining method. This study thus shows that the structural analysis of orogenic gold deposits is critical, and should be a priority for exploration and production in any mine.

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4:45 PMOrogenic-Type Gold Mineralization at Klipwal Gold Mine, Southeastern Kaapvaal Craton, South Africa: Sakthi Chinnasamy1; Ron Uken1; Jürgen Reinhardt1; 1University of KwaZulu-Natal The Kilpwal Gold Mine is located on the Klipwal Shear Zone, in the southeastern part of the Kaapvaal Craton, South Africa. Gold mineralization is confined to laminated quartz-carbonate lodes and associated alteration along the shear zone in sandstone and siltstone of the Delfkom Formation and associated intrusive diabase in the upper Mozaan Group of the Mesoarchaean Pongola Supergroup. The moderately dipping brittle-ductile shear plane strikes N-S and displays an oblique-reverse sinistral sense of shear. Intense anastomosing shears define a shear fabric in the host rocks with numerous shear-parallel laminated quartz-carbonate veins and in places, a quartz vein stockwork. There is evidence of subsequent brittle faulting that reactivated the shear plane. Three closely spaced economic reefs (lodes) are developed: the main R-reef constitutes the shear zone while the J- and H- reefs are footwall splays of varying dip. Alteration comprises chlorite, epidote, sericite and feldspar along with pyrite, arsenopyrite and pyrrhotite ± chalcopyrite. At least two distinct hydrothermal alteration zones are observed. An inner zone, dominated by laminated quartz-carbonate veins and a proximal zone characterized by alteration halos and associated quartz veins. Gold mineralization is confined to flexures in the Klipwal Shear Zone with possible sources of gold derived from: (i) palaeo-placer U-Au rich conglomerates in the underlying Sinqeni Formation of the Mozaan Group (ii) the underlying ~4.6 km thick mafic volcanics of the Nsuze Group; (iii) greenstones belts in the basement to the Pongola basin. Post-Pongola Supergroup granites are considered to have provided the heat to mobilize auriferous fluids into the Klipwal Shear where gold and sulfides were precipitated under suitable physicochemical condition.

WORLD GOLD: Plenary

Monday PM Room: Hampstead / Cote St. LucOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Peter Kondos, Barrick Gold

2:00 PM Panel Discussion Gold Company COO’s and CEO’s. Panel discussion of top leaders in the Gold industry. Guest moderator Amanda Lang, Senior Business Correspondent, CBC News

Panellists include:

· Peter Kinver, EVP and COO, Barrick Gold Corporation · David Harquail, President and CEO of Franco-Nevada · Gordon Stothart, EVP and COO, IamGold Corporation · Sean Roosen, President and CEO, Osisko Mining Corporation

WORLD GOLD: Mineralogy of Precious Metals II

Monday PM Room: Hampstead / Cote St. LucOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: J. Zhou, Consultant

3:15 PMThe Novel Use of XRF Spectrometry in the Refining of Gold: Michael Hinds1; 1Royal Canadian Mint X-ray Fluorescence Spectrometry is used at various stages of gold refining. Initially, incoming impure gold is analysed for content and deleterious elements such as As, Cd, Hg, Se, and Te using a portable XRF spectrometer for a screening assessment. Based on the levels of these impurities the material can be returned to the client or accepted for refining. The gold is then melted and the purity assessed by wavelength dispersive

XRF to determine Au, Ag, Cu, and other elements to assist the Fire Assay of gold and silver. Other elements such as Cu, Fe, Ni, and Zn are also determined and the refinery alerted if any of these elements are abnormally high. A simple energy dispersive XRF is used to determine the end point of chlorination refining step (max 0.5% sum of Ag and Cu) before the gold goes on to the final electrolysis refining. This paper will highlight the utility of XRF to determine impurity concentrations at critical steps in the refining process.

3:55 PMMineralogical Investigation of Carbon Leader Reef samples from TauTona Mine, South Africa: Katarien Deysel1; 1AngloGold Ashanti Gold has been mined from a variety of deposit types that range in age from Archaean to Recent. The large variability in the geological settings of the gold deposits implies transport and concentration of gold by magnetic, hydrothermal and sedimentary processes. The factors that control the concentration of gold at certain sites and the grade estimation thereof remain major topics of debate. Due to the complex nature of the Witwatersrand Basin a mineralogical study, including mineralogical, petrographic and geochemical investigation was launched on TauTona Mine in order to characterize the various reef facies. The aim of the investigation was to determine if a correlation could be found between macroscopic characteristics of the reef, hanging wall and footwall, and the microscopic nature of the ore (especially gold grade).

4:20 PMProcess Mineralogy of the Refractory Gold Part of the Lapa Deposit: Raphael Mermillod-Blondin1; Hassan Bouzahzah2; Mostafa3; Philippe Marion4; Nathalie Valle5; Paul Cousin1; 1Agnico-Eagle Mines; 2University of Quebec in Abitibi-Temiscamingue ; 3INSA Lyon LGCIE; 4Philippe Marion, Laboratory for Environment and Mineral Processing; 5CRP-Gabriel Lippmann The gold deposit of Lapa mine shows a contrasted gold mineralogical state with coarse and fine native gold, aurostibite and submicroscopic gold within arsenopyrite. Pyrrhotite and pyrite are the other main sulphides in the ore. The Lapa mill plant is designed to recover essentially the native gold proportion accounting for 80 to 85 % of the total gold content. A specific mineralogical characterization of the refractory fraction was conducted combining various techniques. The optical microscopy and the electron microscopy have characterized the arsenopyrite grains. The electron microprobe and the secondary ion mass spectrometry have characterized the gold content as well as the gold distribution within the arsenopyrite grains. In parallel, the mineral processing behaviour and the recovery of the refractory gold were studied combining sulphide flotation and pressure oxidation / cyanide leaching of the sulphide concentrate. This paper presents the mineralogical method developed to characterize the gold distribution within arsenopyrite. These results are presented and interpreted in order to plot gold recovery versus sulphide oxidation. The comparison of the metallurgical behaviour yields predicted from mineralogical data and the one calculated from leaching tests shows a good agreement and allows mineralogical explanations of the metallurgical behaviour.

4:45 PMNew Developments in Characterization of Sulphide Refractory Au Ores: Louis Cabri1; Simon Jackson2; 1Cabri Consulting Inc.; 2Geological Survey of Canada Quantitative determination of sub-microscopic gold at sub-ppm concentrations in sulphide minerals can be an important component of deportment studies for sulphide-gold deposits. Modern in situ analytical techniques, which are now capable of low to sub ppb detection limits, are preferred for this application because they are cost-effective and provide not only concentration data but also precise information on the spatial variation of gold and other elements both within and between grains. From 1989, Secondary Ion Mass Spectrometry (SIMS) was the analytical method of choice until about 2003-2005 when Laser Ablation Inductively Coupled

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Mass Spectrometry (LA-ICP-MS) was first successfully applied to sulphide deportment studies using well-characterised fused synthetic pyrrhotite standards. The main advantages of LA- ICP-MS over SIMS are: (1) its greater speed to measure a greater number of elements (typical analysis <2 minutes for ~20 or more elements) – more analyses per day provides more robust statistics and lower costs; (2) much reduced matrix dependence – all sulphide mineral analyses can be accurately calibrated using synthetic pyrrhotite standards; (3) readily variable spot or raster diameter and depth (from <20 to >100 µm) – provides the ability to sample a larger mass for more elements. Recent advances in LA-ICP-MS analysis include the development and application of elemental mapping. This employs multiple line ablations across petrographic sections, allowing sampling of the (polished) surface of entire grains. The data can then be deconvoluted to generate elemental maps which provide detailed information on spatial variations of gold and other elements within grains. This will be demonstrated with specific examples.

5:10 PMProcedure for Characterization of Carbonaceous Matter in an Ore Sample with Estimation Towards its Preg-Robbing Capacity: Brian Hart1; Stamen Dimov1; Raphael Mermillod-Blondin2; 1University of Western Ontario; 2Agnico-Eagle Mines Active carbonaceous matter (c-matter) in sulphide ores can adversely affect the process of gold recovery during cyanidation due to its ability to adsorb, or preg-rob, gold from a cyanide leach solution. This paper describes a standardized procedure for the full characterization of carbonaceous matter in an ore sample. The data will provide an estimate on the impact the c-matter will have on the gold recovery process. The procedure utilizes the following complementary analytical techniques in conjunction to several chemical tests and assays: scanning electron microscopy coupled with energy dispersive x-ray analysis (SEM/EDX), laser Raman spectroscopy (Raman) and Time-of-Flight Secondary Ions Mass Spectrometry (TOF-SIMS). The application of the various techniques and the information they provide are outlined below. SEM/EDX provides compositional analysis of various types of carbonaceous particles in the sample. It identifies the disseminated component within gangue particles and provides information on the distribution of the c-matter within the various grains. The organization of the carbon (maturity), in the carbonaceous matter is determined by laser Raman spectroscopy. The technique uses the shape and width of characteristic Raman peaks for C to provide information on the nature of the carbon bonds. The degree of their symmetry (or asymmetry) combined with their shift in wavelength provides information on the structure of the carbonaceous material. This procedure can differentiate a wide range of carbonaceous materials: from pure graphitic carbon to pure activated carbon. The degree of maturity is reflected in the spectra by the position and shape of 4 different C peaks. By using appropriate deconvolution methods it is possible to identify and measure the degree of C organization (maturity) and, establish a relationship between the preg-robbing capacity (as determined by preg-robbing doping tests) and the nature of the carbonaceous material.

WORLD GOLD: Refractory Ores

Monday PM Room: Mont RoyalOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Chris Fleming, SGS

3:15 PMPilot Plant Pressure Oxidation of Refractory Gold-Silver Concentrate: Michael Collins1; Ding Yuan1; Ian Masters1; Robin Kalanchey1; Lin Yan1; 1Sherritt Technologies Sherritt Technologies recently completed a program of batch and pilot plant pressure oxidation test work for a refractory gold-silver project located in China. The feed concentrate composition was 39 g/t Au, 970 g/t

Ag, 3.3% As, 20% Fe and 22% S; the major sulphide minerals were pyrite and arsenopyrite. Since the feed material contained a significant amount of silver, which is known to be refractory to cyanide leaching after pressure oxidation due to the formation of argentojarosites, the process development work included investigation of methods to enhance silver recovery. The “lime boil” process proved successful and was incorporated into the flowsheet. The pilot plant results confirmed the viability of the pressure oxidation process. Gold extraction from the lime boil residues was 95 to 98%; silver extraction was up to 94%.

3:55 PMRoasting Renaissance- Fluid Bed Roasting for Enhanced Gold Recovery from Double Refractory Ores: Arthur Barnes1; Nathan Stubina2; 1Xstrata Process Support; 2Barrick Gold Corporation Increasingly, gold producers are forced to treat ever more refractory ores. While ores containing pyrite, arsenopyrite and carbonaceous material have been subjected to complete pressure oxidation (POX) as the standard process for such ores, recent improvements in fluid bed roasting technologies have led to a resurgence of interest in roasting as a viable alternative. The lower capital and operating costs of roaster installations add further impetus to this trend. The Extractive Metallurgy Group at Xstrata Process Support operates 3 fluid bed reactors of various sizes which have been utilised on a large number of projects to treat highly refractory ores. Preliminary mineralogical modelling of both the physical and chemical aspects of the roasting process and subsequent testing under carefully controlled conditions has allowed clients to obtain gold recoveries approaching or matching those achievable by POX. The flexibility of the units to operate in various modes- “ bubbling bed”, circulating bed, two stage, sub-stoichiometric and combinations of these, and the range of sample sizes accommodated, from a few kilograms to a few tons, has enabled XPS to accommodate clients with a wide variety of gold bearing refractory ores from all over the world. This paper outlines the key challenges of fluid bed roasting of refractory gold ores, describes the methodology used to design the testwork program and provides some results from select test campaigns.

4:20 PMFluidised Bed Technology for Gold Ore and Gold Concentrate: Marcus Punkel; Jörg Hammerschmidt1; Jochen Güntner1; Ake Holmstöm2; 1Outotec GmbH; 2Outotec AB A significant portion of Outotec’s business relates to the application of fluidised bed for processing a wide range of industrial materials, including gold ore and gold concentrate. As part of the former Lurgi and Boliden organization, our division constructed the first industrial reactor for roasting sulphur-bearing materials in 1950, based on the principles of fluidised bed technology. This process , when combined with efficient heat recovery and off-gas treatment and its conversion to sulphuric acid, eventually became the standard bearer for processing sulphur-bearing ores. In the last 60 years we have delivered more than 265 plants and developed (in addition to the standard fluid bed solution) variants of the fluidisation technology, such as the circulating fluidised bed and the bubbling fluidized bed. This paper describes the different options of the fluid bed technology for gold roasting under reflecting main process design criteria.

4:55 PMThe CESL Gold Process: Tom Robinson1; Keith Mayhew1; David Jones1; Kevin Murray1; 1Teck The CESL Copper Process was developed as a hydrometallurgical alternative to smelting and refining for copper sulphide concentrates. As the majority of such concentrates contain appreciable gold and silver values, effective recovery of these metals is an intrinsic part of any hydrometallurgical processing technology. Unfortunately, conventional cyanide processing cannot be used due to the unusual characteristics of most hydrometallurgical copper residues when compared with naturally occurring gold and silver ores. An abundance of elemental sulphur, as well as the presence of cyanide leachable copper, leads to the formation of both thiocyanate and copper cyanide which is detrimental to process economics due to excessive cyanide consumption. This, however, can be reduced to

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acceptable levels by process innovations such as pressure cyanidation and cyanide recovery. This paper outlines the successful application of the CESL Gold Process to various gold-bearing copper concentrates.

5:10 PMDevelopment (Optimization) of the Detour Lake Concentrator: Integration of the Results of Comminution and the Metallurgical Testwork Program: Jorge Torrealba1; André Allaire1; Rickardo Welyhorsky2; Jean François Dupont2; 1BBA; 2Detour Gold Corporation The Detour Lake property is located in Northeast Ontario, approximately 185 km northeast of Cochrane Ontario. The production of the mineral process plant envisioned will be 55 000 tpd during the first three years of operation and an expansion to 61 200 tpd is planned from the fourth year and beyond. The mill will process a free milling gold ore utilizing both a gravity circuit and leaching with a state-of-the art carbon-in-pulp circuit. The results of the analysis of the pre-feasibility study indicated that further optimization of the circuit configuration was possible. Additional testwork required to support optimization of the plant design criteria for the feasibility study was conducted in a second phase of metallurgical testing and analysis. The test results showed that the recovery of gold was not sensitive to grind size in the range of 75 to 105 microns. An additional result was that the presence of lead nitrate did not improve the kinetics of gold leaching. This conclusion was supported by the low content of sulphides in the ore. It was also found that the presence of lead nitrate increased copper dissolution, producing the potential for an increase of copper reporting to electrowinning, which is detrimental to the overall gold recovery process. The use of oxygen in leaching was investigated as a clean alternative to the use of lead nitrate for an increase to the leaching kinetics. The results of leaching tests to compare using oxygen instead of air indicated that, due to the improved leach time, it was possible to reduce the number of leaching tanks from twenty-four (24) to twenty (20).

WORLD GOLD: Strategic Mine Planning II

Monday PM Room: Fontaine DOctober 3, 2011 Location: Hilton Bonaventure Hotel

Session Chair: R. Henderson, Kinross Gold

3:15 PMThe Resource Valuation and Optimisation Model: Real Options Impact Applied to Mining: G Evatt1; P Johnson1; P Duck1; S Howel3; J Moriarty1; 1School of Mathematics, University of Manchester, U.K.; 2Gemcom Software; 3Manchester Business School, University of Manchester This paper presents the scientific framework underpinning the Resource Valuation and Optimisation Model (RVOM). The RVOM is a Real Options software package, which helps mine owners optimally plan their operations, understand their project risks, and make defensible valuations. This is achieved in the presence of both financial and physical uncertainty. The three key outputs from the RVOM are: Valuation, Optimal Decision and Probability of Decision, where a decision can include normal operation, expanded operation, care and maintenance, and abandonment (and variants thereof). This paper presents a clear example of the RVOMs usage to a case-study gold mine.

3:55 PMUse of Conditional Simulation to Assess Misclassification of Ore and Waste in a High Nugget, Low Continuity Gold/Copper Deposit: Lawrence Allen1; William Hardtke1; Bruce Perry1; Ian Douglas1; 1Newmont Mining Corporation Model reconciliation problems at the low-grade, high-nugget Phoenix gold-copper deposit led to an examination of the influence of production decisions on ore-waste classification. A conditional simulation study of the deposit was used as the basis for: 1) quantification of dilution at different bench heights, 2) quantification of ore-waste misclassification

relative to bench heights and cut-off grades, and 3) determination of an appropriate number of samples to optimize ore-control polygon definition. Actual reconciliation data were empirically used to support conclusions. Simulations of both gold and copper were combined through net revenue modelling. These simulations increased the understanding of the nature of the deposit and provided insight for resource modelling and mine planning.

4:20 PMGoldex Mine – Overview: Jean-Francois Lagueux1; 1Agnico-Eagle Division Goldex The Goldex Mine is an underground gold mine located in the prolific Val-d’Or mining district of northwestern Québec, Canada. Because of its shape and low grade, the Goldex deposit is mined using a hybrid mining method midway between block caving, longhole stoping and shrinkage. Since most of the ore is stored inside one big stope and only one extraction level is available, sequencing of the extraction is crucial to both minimize dilution and ensure stability of the stope walls. After less than 3 years of production and 25% of the material extracted from the mine, Goldex remains a continual challenge for the team in place. After the development and construction phases, production requires adaptation and innovation from the staff, contractors, consultants and suppliers to always keep in focus the cost reduction and safety at the mine complex. Goldex is, at this time, one of the lowest UG gold producers with an average cost below 23Cnd$/t and remains in good position to increase mine life by addition of satellite zones and good exploration targets below the GEZ zone. Goldex has managed to maintain very good relationships with neighbours and community although the operation is very close to city limits. Decisions on operations and management of mining site were always based on welfare of the population and represented a team effort of all concerned. The Goldex goal remains to be an example by increasing industry standards.

4:45 PMA Segmented Reconciliation Matrix Approach to Monitor Gold Operations and Reserve Estimation: Ana Chieregati1; Luiz Pignatari2; Kim Esbensen3; Francis Pitard4; 1University of Sao Paulo; 2YamanaGOLD; 3GEUS; 4FPSC Mine reconciliation is seen, for many, as a test of the quality of model estimates, while in fact it should be seen as a powerful tool for detecting and correcting problems in each step of mining operations, from resource estimation to metal production. Adequate reconciliation practices allow a more efficient control of the mining processes; however, its results can be illusory unless all parties involved have been in compliance with the principles of sampling correctness. This paper presents a new, segmented reconciliation matrix, which is based on the Theory of Sampling (TOS), developed to monitor gold operations and reserve estimation.

5:10 PMHigh-Order Spatial Simulation of the Structurally Controlled Apensu Gold Deposit, Chana: David Machuca Mory1; Roussos Dimitrakopoulos1; 1Stochastic Mine Planning Laboratory, McGill University Stochastic simulation techniques are used for assessing the uncertainty in the spatial distribution of grades in a deposit. Among them, Gaussian based simulation algorithms are popular. These rely on the assumption that the spatial relationship between different locations can be described by a standard multivariate Gaussian model and the covariances between them. This hinders the modelling of non-linear and non-Gaussian mineralization patterns. Several new simulation techniques are based on training images. A representative training image is assumed to contain the patterns of the spatial distribution of grades in a deposit. These new algorithms do not require of the Gaussian assumption and are able to reproduce complex mineralization patterns. However, the effort of building a representative training image of grades may amount as the effort of building the final model. Moreover, if the training image is not representative, the simulated model will be erroneous. The proposed algorithm is based on the use of cumulants and do not require the assumption of a probabilistic distribution

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model. Cumulants are statistics that characterize the spatial relation between three or more points. They are obtained directly from data and backed by a training image when data is very sparse. The resulting realizations honour the probabilistic distribution of data as well as their complex spatial structure. In this paper, the proposed multiple-point simulation algorithm is applied to a structurally-controlled gold deposit to produce multiple realisations of grades. The data used comes from a drill-hole exploration campaign. The resulting realizations are compared with those produced by Gaussian simulation. The realizations obtained using multiple-point simulation reproduce better the complex spatial features of gold mineralization. Stochastic ore resource models that are geologically more realistic are potentially a better basis for mine planning and design.

GENERAL PLENARY: General Plenary II

Tuesday AM Room: Westmount/OutremontOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Cessar Inostroza, Rio Tinto Alcan

8:30 AM PlenaryNRU Vessel Repair Project: Sandra Celovsky1; Dave Cox1; Hank Drumhillers; 1AECL In May 2009, following a Class 4 power outage that affected most of Eastern Ontario, including the Chalk River Laboratories site, Atomic Energy of Canada Limited (AECL) announced to its various stakeholders that a small heavy-water leak in the NRU reactor had been detected during routine monitoring while the reactor was being readied for return to service. Over the next 15 months AECL located, inspected, repaired and returned the NRU reactor to service. This presentation will focus on the extensive efforts required to support the unique activities associated with reactor vessel inspection and repair including initial assessment, repair site challenges, repair preparation and finally repair execution. Specifics to be included in the presentation include: Initial leak search and assessment of the vessel condition through the use of specialized tooling and non-destructive evaluation which resulted in one of the largest single NDE inspection campaigns ever carried out in the nuclear industry. Specifics related to the challenges of executing a repair through 12 cm access ports at a distance of nine meters including the development of the specialized tooling. The importance of development of repair techniques through mock up testing to perform welding repairs on a thin wall aluminium vessel and the measures taken and engineering challenges overcome to achieve a successful repair. The final repair process, including site preparation, weld execution and final NDE inspection techniques.

8:55 AM PlenaryCanadian Mining Credentials Program – Certification: Recognizing and Retaining Skills: Barbara Kirby1; 1Mining Industry Human Resources Council This presentation will describe the Canadian Mining Credentials Program - a new nationally-recognized skills recognition and certification program for the mining industry. The latest research by the Mining Industry Human Resources (MiHR) Council estimates that between now and 2021 the industry will need to hire approximately 112,000 workers to both support growth in the industry and replace retiring workers. Almost 35,000 of these new hires will be required in skilled occupations that have up until had now lacked a national recognition system, including production miners, development miners, heavy equipment operators and mill operators. The presentation will also touch on the complex collaborative effort required to bring this program to fruition, key observations from the pilot sites and why the program forms an essential part of the industry strategy to address the looming labour shortage.

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LIGHT METALS: Aluminium Transformation I

Tuesday AM Room: LasalleOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Yves Verreman, Aluminium Research Centre - REGAL, Ecole Polytechnique de Montréal; Dimitry Sediako, Canadian Neutron Beam Centre, National Research Council of Canada

9:30 AMA Self-Consistent Model for Predicting the Mechanical Behavior of Cold-Drawn 6063 Aluminium Tubes: Hien Bui1; Tan Pham2; Mario Fafard1; 1Laval University; 2École de technologie supérieure The elastoplastic self-consistent model is one of the effective models to study the initial microstructure effect on the mechanical behavior of bulk materials. However, the use of this micromechanics-based model which takes into account only the Hall-Petch relationship at grain level for predicting the grain sized effects on the strength of the deformed materials is not accurate yet because of the fact that the dislocation density contributes also to the strengthening of this kind of materials. In this study, a modification made to the Hill-Hutchinson elastoplastic self-consistent model was proposed for investigating the microstructure dependence of the mechanical behavior of cold-drawn 6063 aluminium tubes. Because of the novel modification, an optimization procedure with two objectives was required to identify the parameters of this micromechanical model. An acceptable agreement between experimental and theoretical stress-strain curves was achieved.

9:55 AMMachinability of A356 and A319 Aluminum Alloys: Jules Kouam1; Zedan Yasser1; Abdelhakim Djebara1; Jacques Masounave1; Victor Songmene1; 1Ecole de Technologie Superieure Aluminum alloys, widely used in the automotive industry, can be classified as low machinability because of chip formation and aluminum’s strong tendency to adhere to the cutting tool, especially when machined dry, leading to short tool life and low productivity. Dry machining is being recommended because of its beneficial effects on environment and on machining costs. Although cast alloys are usually considered as brittle materials leading to short chip formation, they can also produce long and continuous chips depending on machining conditions used. This type of chips are not easy to manage and can deteriorate the cutting tools and the machined parts. Also, the machinability of these materials can be improved by improving their metallurgical treatment. This study was designed to understand the cutting performance during dry drilling of A319 and A356 cast alloys in conditions T0 and T6. A multi-level factorial design (DOE) was used for the experiments. The machinability was assessed using the chip form, the chip breakability and the cutting forces. Scanning Electron Microscopy (SEM) investigations showed that the chip segmentation depends on the additive element such as copper. Both the workpiece materials microstructure and the machining conditions have significant effect on the chip formation mechanism. Therefore, the machining parameters could be selected to promote a desired chip form easy to manage in production.

10:35 AMEffects of the Melt Thermal Treatment Process on the Tensile Properties of 356 Type-Alloys: Hu Chen1; Agnes-Marie samuel1; Hany Ammar2; Fawzy Samuel1; Abdulrahman Al-Ahmari3; 1Université du Québec à Chicoutimi; 2Center of Excellence for Research in Engineering Materials, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia; 3Center of Excellence for Research in Engineering Materials, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia The tensile test results of the A356 alloy castings in the as-cast condition show that the tensile strength can be improved by strontium modification (SrM), superheating at 900°C (SH), and strontium modified melt thermally treated (SrMTT) process. Both SrM and SrMTT process can greatly improve the percentage elongation of the as-cast A356 alloy castings. During solution heat treatment at 540°C, eutectic Si particles undergo fragmentation, spheroidization, and coarsening, thereby affecting the relevant particle morphology. The effects of solution heat treatment on the tensile properties of the various A356.2 alloy castings can be summed up as follows. The yield strength of the various A356.2 alloy castings is significantly improved after 8 h solution heat treatment due to the precipitation of Mg2Si. The yield strength remains more or less the same with the further increase in solution treatment time to 80 h. The ultimate tensile strength is also greatly improved within the first 8 h of solution heat treatment and then remains at the same level as solution time increases up to 80h. The improvement is attributed to Mg2Si precipitation, dissolution of Si within the aluminum matrix, and changes in the Si particle morphology (spheroidization). The ductility of the as-received grain refined non-modified (NM), grain refined and superheated at 900°C (SH), and melt thermal treated grain refined (non- modified) processed (MTT) A356.2 alloy castings can be improved considerably with solution heat treatment e.g. from ~6% in the non-modified casting in the as-cast condition to ~10% after 80 h solution treatment.

11:00 AMVirtual Modeling in Tube Hydroforming Process of Complex Aluminum Parts: Mihaita Matei1; Augustin Gakwaya1; Julie Lévesque1; Michel Guillot1; 1Laval University An adaptive approach to control the deformation in tube hydroforming process is presented. This requires: the use of an existing non-linear FE software (ABAQUS) that incorporates a user material model (VUMAT), the development and implementation of an adaptive control strategy to coordinate the internal pressure and the axial load so as to prevent fracture and wrinkling failures (knowledge-base controller) and the application of the developed adaptive simulation approach for finding the optimal loading path required to hydroform a defect-free part with as uniform thickness distribution as possible (user’s load subroutine (VDLOAD). In order to validate the approach, the case of conical hydroforming and the case of bending followed by hydroforming component is discussed.

11:25 AMEffect of Lubrication and Application Modes on Drilled Aluminum Part Quality: Yasser Zedan1; Riad Khettabi1; Victor Songmene1; Jacques Masounave1; 1ETS Cutting fluids play important roles during machining including reduction of friction and temperature. The use of the cutting fluid, however, degrades the quality of the environment and increases the machining cost. The aim of the present research work is to study the effect of cutting fluids and its interactions with cutting parameters and workpiece heat treatment on surface finish and burr formation during drilling of 7075, 6061, and A356 aluminum alloys. Multi-factorial experimental design (DOE) and analysis are used. A procedure has been developed to asses and optimizes the chosen factors to minimize burr formation and surface roughness. It has been found that the dry machining can be competitive compared to wet machining in term of part quality when using the optimal cutting conditions.

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11:50 AMResidual Stress Mapping in the Interbore Region of a Heat Treated Aluminum Engine Block: Dimitry Sediako1; Anthony Lombardi2; Francesco D’Elia2; Comondore Ravindran2; Alan Machin2; Ronald Rogge1; Robert MacKay3; 1National Research Council of Canada; 2Ryerson University; 3Nemak Canada Corporation Excessive residual stress in Al engine blocks may result in cylinder distortion which reduces engine operating efficiency. As such, neutron diffraction was used to measure residual strain along the Fe liners and Al, in the hoop, radial and axial orientations with respect to the cylinder axis, at the cylinder interbore region. Residual stresses were subsequently calculated using generalized Hooke’s law and related to the microstructure along the cylinder bridge. The results suggest that the residual stresses in the Al interbore region are tensile and increase with depth within the cylinder. The increase in residual stress at the bottom coincides with a finer and more uniform microstructure in this region of the cylinder. The refinement in microstructure at the bottom of the cylinder likely increased alloy strength, thereby decreasing this section’s susceptibility to distortion.

LIGHT METALS: Light Metals Ti and Mg

Tuesday AM Room: LachineOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Franco Chiesa, Aluminium Research Centre - REGAL, Centre de métallurgie du Québec; Mihaiela Isac, McGill Metals Processing Centre

9:30 AMInfluence of Mold Coating on the Metallurgical Quality of Titanium Cast into Graphite Ingot Molds: Bernard Tougas1; Franco Chiesa1; Martine Comtois-Parr1; Lucie Forget1; Gheorghe Marin1; 1Centre de Metallurgie du Quebec Recycling of titanium represents an important economic activity due to high cost of the material and the amount of returns of machined parts which represent the bulk of finished titanium products (typical “buy to fly” of 10 in the aeronautic industry). In the present work, the metallurgical quality of 76 mm in diameter and 20 cm ingots poured in coated graphite mold will be assessed against the nature and condition of application of 4 coatings namely aluminum oxide, yttrium oxide, zirconium oxide and zirconium oxide with 4% aluminum oxide. The metallurgical quality has been evaluated in terms of alpha case thickness, microstructure and composition. Microhardness from surface will be assessed against casting conditions. Least square regression analysis have been use to optimize casting conditions.

9:55 AMCharacterization of AZ91 Type Alloy with Silicon Addition: Sophie Lun Sin1; Comondore Ravindran1; 1Ryerson University This research focused on the effect of silicon on the hot tearing susceptibility of permanent mould cast AZ91E magnesium alloy. Varying amounts of silicon (0.5, 1.34 and 1.5 wt%) were added to AZ91E in the form of an Al-53 wt% Si master alloy. The microstructure, grain size and solidification behavior of each alloy were characterized and related to their hot tearing susceptibility. The results showed that silicon significantly reduced the hot tearing susceptibility of AZ91E. This was attributed to a reduction in grain size and decrease of the freezing range of AZ91E, which thereby improved interdendritic feeding during the last stage of solidification. This research demonstrates the effectiveness of silicon in improving the castability of AZ91E alloy by alleviating hot tearing.

10:35 AMEvaluation of Hot Cracking in AZ91E and AE42 Mg Alloys: Francesco D’Elia1; Comondore Ravindran1; K. Prasad Rao2; 1Ryerson University; 2Indian Institute of Technology - Madras Hot cracking of magnesium (Mg) alloys during welding creates a barrier to enhancing the use of these alloys in automotive applications. As a result, it is imperative to understand the mechanisms responsible for hot cracking of Mg alloy welds in order to develop means of eliminating this problem. In this study, the hot cracking susceptibility of AZ91E and AE42 magnesium alloys were assessed using the moving torch Varestraint test method. Plates of 3 mm thickness were extracted from AZ91E and AE42 ingots and subsequently tested. Quantitative cracking data in terms of maximum crack length (MCL) was used for evaluating the cracking susceptibility. Optical and scanning electron microscopy was carried out. The results suggest that AE42 showed a higher resistance to hot cracking in comparison to the AZ91E alloy. This was attributed to the difference in freezing ranges between the two alloys. The relatively long freezing range of AZ91E enabled segregation of Mg17Al12 into grain boundary regions, which weakened these regions and led to hot cracking. In contrast, siginificantly less segregation of secondary phases in AE42 occurred, thereby resulting in no hot cracks.

11:00 AMImproving Melt Cleanliness and Mechanical Properties of AZ91E Permanent Mould Castings with Melt Filtration: Abdallah Elsayed1; Mobaraz Khokhar1; Comondore Ravindran1; 1Ryerson University Increased dependence on fossil fuels has promoted a higher concentration of carbon dioxide within the atmosphere that has been linked to changing weather patterns and other extreme weather phenomenon. An increase in fuel economies of transportation vehicles by reducing component weight could help counteract carbon emissions. Lightweight metals such as magnesium show potential in replacing aluminum alloy castings for engine cradles, cylinder heads and transmission cases. Unfortunately, magnesium alloys are susceptible to entrapping oxides and other impurities during casting pouring and solidification. The presence of these unwanted particles seriously hinders the strength and ductility of magnesium permanent mould castings. The current study examined various filter sizes and configurations in hopes of improving the mechanical properties of permanent mould cast AZ91E by reducing the presence of oxides and inclusions.Specimens for tensile testing were prepared using a H13 permanent tensile mould in accordance with ASTM standard B108-06. The castings were produced with pouring and mould temperatures of 720 °C and 400 °C. The castings were produced in four different configurations: no filter, coarse filter on top of sprue, coarse filter within sprue, coarse filter within well and a fine filter within well.The use of filters during castings was an easy and effective method to produce consistently sound castings with improved mechanical properties for commercial use. Further research aims to optimize material properties and dimensions of the filters and utilize casting simulation software to model mould filling with and without filters.

11:25 AMThermodynamic Modeling of the Mg-Cu-Ni Ternary System using the Modified Quasichemical Model: Mohammad Mezbahul-Islam1; Mamoun Medraj1; 1Concordia University Thermodynamic modeling of the Mg-Cu-Ni system has been carried out as a part of multi component thermodynamic database for Mg alloys. This system has been modeled for the first time using the modified quasichemical model which considers the presence of short range ordering in the liquid. The Cu-Ni binary system has been re-optimized based on the experimental phase equilibrium and thermodynamic data available in the literature. The optimized thermodynamic parameters for the Mg-Cu and Mg-Ni systems have been taken from the previous thermodynamic assessment of the Mg-Cu-Y and Mg-Ni-Y systems by the same authors. The thermodynamic descriptions of the binaries Mg-Cu, Cu-Ni and Mg-Ni have been extrapolated to the ternary Mg-Cu-Ni system using Toop geometric model which is an asymmetric model. Mg has been singled

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out as the asymmetric component since Cu-Ni system showed completely different thermodynamic characteristics than Mg-Cu and Mg-Ni binary systems. The sublattice model has been employed to describe the CuMg2 Cu2Mg, NiMg2 and Ni2Mg compounds. The ternary solubility of these compounds has been modeled properly by involving temperature dependent parameters. The constructed database has been used to calculate and predict thermodynamic properties, isothermal sections and liquidus projections of the Mg-Cu-Ni system which showed very good consistency with the experimental data.

11:50 AMA Study on the Deformation Behavior of Mg and Mg Alloys Using 4D Processing Maps: Shashi Prakash Narayan1; Sasi Bhushan Bhimavarapu1; Deepti Bhargava1; Amit Kumar Maheshwari1; 1Advanced Materials & Processes Research Institute (CSIR) The hot deformation behavior of Pure Mg and Mg-0.29Ce alloy were studied by isothermal hot compression tests in the temperature range of 250 - 5000C and strain rate range of 10-3 - 102 s-1 in a computer-controlled 50kN servo hydraulic universal testing machine (UTM). The results show that the flow stress of Mg pure and Mg-0.29Ce alloy increases with strain rate and decreases after a peak value, indicating dynamic recovery and recrystallization. Process efficiency was increased by nearly 10 to 12% by addition of Ce in Mg. Mg pure exhibits instability zones between 250-2750C at 101 – 102 s-1 and 400-5000C at 101 – 102 s-1 temperatures and strain rates respectively, rest is the safe deformation zone. Wherein, Mg-0.29 Ce exhibits two low efficiency zones at 250 – 3000C at 10-2 – 100 s-1, 400 – 5000C at 101 – 102s-1 and high efficiency zone at 450 – 5000C at 10-3 – 10-1s-1. 4D process maps were generated for the above said alloys which illustrate contours of power dissipation and instability in the 3D space of strain rate, temperature and strain.

LIGHT METALS: REGAL’s Student Day

Tuesday AM Room: Le PortageOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Myriam Brochu

8:10 AM Mot de bienvenue et ouverture de la JER: Myriam Brochu; École Présidente de l’événement et Daniel Larouche, Directeur REGAL

8:20 AMPrédiction inverse d’un front de solidification: solutions au phénomène diffusif: Marc-André Marois; Aluminium Research Centre – REGAL, Université de Sherbrooke

8:50 AMProtection of Copper and Aluminum Alloy Surfaces using Corrosion Resistance Nanostructured Superhydrophobic Coatings: Ying Huangs; Aluminium Research Centre – REGAL, UQAC

9:20 AMSome Developments in the Production Technologies of Complex Aluminium Tubes: Reza Bihamta; Aluminium Research Centre – REGAL, Université Laval

9:50 AMCharacterization of Fine and Ultrafine Particles Produced During Dry Machining of Aluminum Alloys: Abdelhakim Djebara; Aluminium Research Centre – REGAL, ETS

10:35 AMThe Role of Minor Nickel Additions on the Microstructure and Mechanical Properties of Al-Si-Mg-Cu Alloys: Amir Rezaei-Farkoosh; Aluminium Research Centre – REGAL, McGill University

11:05 AMDuctile Fracture of AA2198 Aluminum-Copper-Lithium Alloys in the Aeronautical Industry: Jian Qiang Chen; Aluminium Research Centre – REGAL, École Polytechnique de Montréal

11:35 AMThe Origin and Evolution of the Aluminium Smelter Technology in Canada: Georges Holywell

12:00 PM - 2:00 PMREGAL Lunch, mot du Directeur, remise des bourses Rio Tinto Alcan

2:00 PM - 6:00 PMPoster Session

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MANAGING THROUGH RECESSION: Managing Through Recession I

Tuesday AM Room: Fontaine GOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Daniel Brosig, Hatch

9:30 AM KeynoteNext 50 years - Mining and Metallurgy in Canada at a Crossroads: New Golden Cycle or Bust?: Nathan Stubina1; Mackey Phillip2; Joël Kapusta3; 1The Mining Association of Canada; 2P.J. Mackey Technology Inc; 3BBA A special commemorative book is being published as part of this year’s quinquagenary. The book documents how the “metallurgical landscape” in Canada has evolved over the past 50 years. This retrospective also provided us with an opportunity to look forward and try to predict the forces that will shape our metallurgical and material industries 50 years into the future. This paper explores some of the key issues that the industry will likely face in the future. A brief survey was sent out to a select group of MetSoc members during the summer of 2011. This presentation will also summarize their views.

10:35 AMTracking the Trends 2011 - The Top 10 Issues Mining Companies Will Face in the Coming Year: Jurgen Beier1; 1Deloitte & Touche This presentation is based on global research undertaken by Deloitte which identifies the top 10 issues mining companies will be required to deal with in 2011. The ten issues which will be discussed in the presentation are: 1. The fickel face of financing 2. When supply can’t match demand, 3. Securing a social license to operate, 4. New taxes, new regulations and new governments,5. How to invest more strategically,6. The war for talent, 7. At the end of the rainbow - maintaining the search for new deposits, 8. Climate change disclosure, 9. Inadequate infrastructure in developing jurisdications,10. New revenue opportunities

11:00 AM Can the Implementation of Innovative HR Practices Reduce the Effects of the Cycle?: Barbara Kirby1; 1Mining Industry Human Resources Council During the recent downturn, several mining employers shifted their focus from long term HR planning and aggressive recruitment to implementing cost saving measures through hiring freezes, temporary shutdowns, reducing their support for students and even layoffs. As short lived as the recession was, mining companies are now faced with renewed challenges around attraction, recruitment and retention in the face of significant labour shortages. In fact, the latest research from the Mining Industry Human Resources Council (MiHR) indicates a need to hire over 100,000 people by 2020 to meet the needs of the sector. To address the skills shortage and reduce the effects of the cycle, the mining industry has recognised that it needs to collaborate. Collectively, we can implement the strategies needed to ensure an appropriately skilled workforce is in place and maintained through the volatility of commodity cycles. Mining Industry Human Resources Innovate (www.mihrinnovate.ca) is a collaborative platform for sharing knowledge and effective HR practices and initiatives, in the interest of working towards addressing the HR challenges specific to the mining industry. This session will focus on the HR challenges in mining and highlight examples of innovative HR practices from Vale, DeBeers, Cameco, Noront and Goldcorp submitted to MiHR innovate.

11:25 AM InvitedRestructuring during the Credit Crunch: Teck’s Experience: Ron Millos1; 1Teck Resources Ltd. By taking positive steps, Teck was able to withstand the credit crunch. In this session learn how management developed and stayed focused on a strategy for reducing the firm’s debt and refinancing the corporation to take advantage of opportunities in a recovering economy.

MATERIALS - INNOVATIONS IN JOINING OF ADVANCED MATERIALS: Understanding Innovations

Tuesday AM Room: LongueuilOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Mathieu Brochu, McGill University; Joel Pepin, AITF

9:30 AM KeynoteSuccessfully Patenting New Materials and Processes: Evangellos Vekris1; 1Sim & McBurney Materials research efforts often give rise to materials and processes that are eligible to be protected by a patent. In today’s business environment, patents are playing an increasingly valuable role in a company’s intangible assets. A diverse patent portfolio that contains an array of different patents can enable a company to corner the market and to thereby obtain a monopoly. In the academic world, one or more patents can provide a foundation for growing a start-up company, and can enable investment funds to be secured. The inherent value of patents was recently demonstrated by the U.S. Courts in i4i Ltd. v. Microsoft Corp., which resulted in a payout of $290 million USD by Microsoft to the Canadian owners of the U.S. patent at issue. However, though patents are inherently valuable, there are steps that must be properly followed in order to successfully obtain a patent. Failure to follow these steps, such as by prematurely disclosing an invention to the public, can be detrimental or even fatal to obtaining a patent, and can result in inadvertent loss of all rights to that invention. The steps for successful patenting, and the pitfalls to be avoided, will be reviewed.

10:35 AMFailure Mechanisms in Thermo-Mechanical Fatigue of DS Superalloy Rene 80: E. Abrokwah1; N. Richards1; O. Ojo1; 1The University of Manitoba Directionally solidified (DS) Rene 80 Superalloy was tested in thermo-mechanical fatigue (TMF) over the temperature range 500-900°C and plastic strain levels from 0.2 to 0.8% using a DSI Gleeble thermal simulator. Thermo-mechanical testing was carried out on the parent material in the conventional solution treated and aged condition (STA), as well as gas tungsten arc welded with an IN-738 filler, followed by solution treatment and ageing. Comparison of the base TMF unwelded alloy with that of the welded and heat treated alloy showed that varying crack initiation mechanisms, notably oxidation either by stress assisted grain boundary oxidation, or associated with grain boundary MC carbides fatigue crack propagation along grain boundaries and creep deformation were operating, leading to different “weakest link” failure initiation points.

11:00 AMDetermination of the Constitutive Behaviour of AA6022-T4 Aluminium Alloy Spot Welds at Large Strains: Jidong Kang1; Joseph McDermid1; David Sigler2; Darren Edmison; 1McMaster University; 2GM Global R&D There is increasing demand to utilize aluminium alloy sheets and their spot welds by the automotive industry. While traditional uniaxial tensile tests only determine mechanical properties to small strain, direct measurement of the constitutive behaviour of aluminium alloy spot welds at large strain remains a challenge. A technique was successfully developed using digital image correlation coupled with shear tests to directly measure the constitutive behaviour of an AA6022-T4 spot weld to large strains. The results show that the spot welding process not only decreases the yield strength but also lowers the work hardening rate of the nugget versus the base material. Details of sample preparation, experimental approach and results will be discussed.

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11:25 AMMechanical Properties of Inconel 600 Welded to Carbon Steel: Steven Knapp1; Arnaud Weck1; 1University of Ottawa Inconel 600 pipes welded to Carbon-Steel are used in CANDU nuclear reactors. Fracture of these welded tubes would have important consequences in term of safety, and therefore their mechanical properties need to be better understood. In this study, the weld region was analyzed at various length-scales using optical microscopy, micro hardness testing, small and large scale tensile testing and digital image correlation (DIC). Large grains were observed in the weld region and smaller grains in the Inconel and carbon steel base metals. Micro-hardness profiles showed variations across the weld and through thickness and were justified in terms of residual stresses in the sample. Large tensile samples were extracted from the welded pipe and were used to identify the material in which fracture initiates. In addition, the local strains in each material were obtained using digital image correlation. Local stress-strain curves were built from the DIC data and compared to stress-strain curves obtained from miniature tensile samples extracted from the carbon steel, Inconel and weld regions. The results demonstrate the advantage of using DIC for extracting local material properties in dissimilar weld systems. Variations in the materials stress-strain curves thought thickness are also presented and emphasize the need for obtaining a complete map of the mechanical properties in the weld region for predictive models to be accurate. Preliminary fracture studies will also be presented.

NEW TECHNOLOGY IMPLEMENTATION IN METALLURGICAL PROCESSES: Industry-University Interaction

Tuesday AM Room: Fontaine HOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Ken Coley, McMaster University

9:30 AMVale-Cytec-University Research Consortium on Processing Low Grade Ultramafic Nickel Ore: Manqiu Xu1; Ken Scholey1; Sam Marcuson1; 1Vale Base Metals Technology Development As high grade nickel sulphide ores are being depleted and the continuing challenges in economically processing nickel laterite ores, it is important to develop technologies to extract nickel from low grade ultramafic ores present in large quantities worldwide. In the Thompson Nickel Belt there are some 300 millions tonnes of mineralization that are potentially amenable to surface mining. Since discovery of the Thompson orebody, recovery of nickel from these ultramafic deposits has been an elusive goal. Research and development projects as well as commercial processing have been attempted. In the 2000’s as other resources became scarcer, a major drilling, mine evaluation and research project was initiated. In 2007, Vale Base Metals Technology Development invited Cytec and potential academic partners to participate in an industry-university research consortium with the goal of developing new technologies and methods of processing the ultramafic deposits. Three university professors, J. Finch of McGill, P. Somasundaran of Columbia and R. Pelton of McMaster accepted, each group attacking the problem with a different approach. This paper describes the management of the research consortium and the significance of the results from Vale’s perspective. The next four papers in this session will summarize the project and results from the partners’ point of view. Vale is pleased to share the experience of the collaborative research and development with the mining industry.

9:55 AMMcGill Contribution to Vale’s Ultramafic Project: James Finch1; Mitra Mirnezami1; 1McGill University The McGill component of the consortium took on detailed examination of the electrokinetic properties of the constituent minerals, primarily pentlandite and serpentine. Mineral specimens were derived from an ore sample; mineralological examination showed the serpentine was predominantly clinochrysotile. The study included design of a novel sedimentation potential measuring device to classify the surface charge of the ore and electrophoresis measurements on single and mixed minerals which progressively approached flotation conditions. The sedimentation potential measurements provided a general association surface charge and the visual state of aggregation as a function of pH. The device was subsequently modified to measure bubble swarm potential to test the hypothesis that serpentine is floated by hetero-coagulation with bubbles, work still in progress. The electrophoresis experiments started with single minerals in a background of indifferent electrolyte and progressed to mixed minerals in a background of supernatant derived from an ore sample. The single mineral tests supported the suspected electrostatic interaction at flotation pH, the pentlandite being negatively charged the serpentine positively charged. The mixed mineral tests upheld this interaction but also revealed hetero-coagulation with Mg(OH)2 precipitates, derived from the supernatant, at flotation pH. This interpretation was confirmed by optical and electron beam imaging. A series of agents, CMC, polyphosphate, soda ash, EDTA, were examined to disperse the system. To accommodate the small mass of mineral a novel turbidity measurement using a UV/Vis spectrophotometer was used to estimate degree of dispersion. Selected conditions were used in contact angle and small scale flotation tests. The series of meetings provided a forum for interchange of ideas and results which were used to guide batch and mini-plant flotation tests at Vale. The outcomes for McGill include training of 2 PhDs and 3 coop students and publication of 4 conference papers and 3 journal articles with 4 more to be submitted.

10:35 AMImpact of Aspect Ratios of Serpentines in Beneficiation of Ultramafic Ni Ores: PARTHA PATRA1; Mukund Vasudevan2; Tarun Bhambani2; D. R. Nagaraj2; P. Somasundaran1; 1Columbia University; 2Cytec Industries Inc Historically, efficient beneficiation of ultramafic Ni ores has been difficult to achieve. This is due to the lack of clear-cut scientific understanding of the effects of serpentine in processing. Recent research efforts at Columbia-Cytec as a part of the Vale JDP have led to new insights into these problems. Factors other than slime coating were found to be more important - namely (a) pulp rheology, and (b) Mg silicate transport to froth phase. The severity of the effect of these factors is predominantly dependent on the aspect ratio of Mg silicates. For example, the pulp viscosity increases with increase in the aspect ratios of the fibers leading to poor Ni separation. Effects of varoius reagents and schemes on pulp viscosity will be explored in this talk.

11:00 AMEfficient Processing of Ultramafic Ni Ores: Challenges and Solutions: Mukund Vasudevan1; D.R. Nagaraj1; Partha Patra2; Tarun Bhambhani1; P. Somasundaram2; 1Cytec Industries, Inc.; 2Columbia University Selective Ni separation from ultramafic ores rich in serpentines has been a huge challenge in the mineral processing industry, and therefore highly inefficient. Analysis of the root causes of the challenges and consequent development of robust processing solutions were the main goals of the Cytec-Columbia University-Vale Joint Development Program, and also forms the subject matter of this paper. The main finding of this research program was that the metallurgical problems were driven through two main pathways - namely pulp rheology and Mg silicate transport to froth phase – that were dictated by a central factor, i.e. the morphology of the serpentine minerals. In light of these challenges, the application of proprietary Cytec modifiers led to substantial improvements in metallurgical performance, and significantly improved processing efficiency.

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11:25 AMNanoparticle Flotation Collectors – Innovation from Collaboration: Robert Pelton1; Songtao Yang1; Manqui Xu2; Zongfu Dai2; 1McMaster University; 2Vale Five years ago, Vale (then INCO), approached Pelton’s group at McMaster to introduce a challenging mineral separations problem. The McMaster group has a strong track record in colloids, polymers, and chemical additives for papermaking; however, they had no experience in mineral processing. Perhaps out of ignorance, they proposed employing hydrophobic nanoparticles to replace conventional low molecular weight, water-soluble flotation collectors. Over the last five years, Vale, together with the Ontario Government (OCE) have funded two graduate students at McMaster who have worked closely with flotation experts at Vale. Experiments involving both very clean model mineral suspensions at McMaster and complex ores at Vale, have shown that hydrophobic nanoparticles do indeed function as collectors. Key nanoparticle properties and mechanisms have been identified and the technology has been protected in patent applications - efforts to commercialize the technology are on-going. We believe that this project is a good case study demonstrating the advantages of industry-university collaboration and for bringing in outside experts who may come up with novel solutions to complex problems.

WASTE RECYCLING IN MINERAL AND METALLURGICAL INDUSTRIES: Metallurgical Slag, Dust

Tuesday AM Room: VerdunOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Charles Jia, University of Toronto; Chris Pickles, Queen’s University

9:30 AMRecycling Waste Polymeric Materials for Slag /Carbon Interactions in EAF Steelmaking: Veena Sahajwalla1; Magdalena zaharia1; Somyote Kongkarat1; James Dankwah1; Rita Khanna1; Narendra Saha-Chaudhury1; Paul O’Kane2; Catherine Skidmore2; Jonathan Dicker2; David Knights2; 1University of New South Wales; 2OneSteel Due to the inherent limitations of current methods of disposal of wastes derived from polymeric materials, avenues are researched towards developing alternative, environmentally friendly and economic recycling processes. Different polymeric materials (i.e. rubber, high density polyethylene (HDPE), polyurethane (PU) and polyethylene therephtalate (PET)), quite distinct in terms of chemical structure and composition, were considered in the present study as carbon resources in EAF steelmaking. Investigations were conducted in both laboratory and industrial scale steelmaking to assess the effectiveness of using these materials as carbon sources for slag foaming in EAF steelmaking. Slag foaming is important because it enhances furnace efficiency. Using the sessile drop approach, interfacial reactions taking place in the slag/carbon region were investigated at 1550ºC in a horizontal tube furnace under inert atmosphere (1l/min Ar). In-situ dynamic changes occurring during slag/carbon interactions were captured at high temperatures, images were extracted from the videos and volume changes were analysed. The system was quenched at high temperatures to study gas entrapment that occurred while using different materials.The rapid heating to high temperatures provided during steelmaking will break down the polymeric chains and the direct physical contact with liquid slag will enable gas formation when introduced into the slag phase. The generation of gas at high temperatures from the carbonaceous samples is investigated using a Infrared (IR)/gas chromatographic (GC) analyser. The entrapped gas and the reduced iron are observed through the optical microscopic images of slag droplets.Dynamic changes in volume of the slag droplet, while in contact with the solid coke/

polymeric material substrate is measured and a comparison shows that chemical propertiesy of the polymeric materials plays an important role in the gasification of the blends which influences slag foaming.

9:55 AMRecovery of Iron from Waste Slag of Pyrite Processing Using Reduction-Roasting Magnetic Separation Method: G.F. Zhang1; Q.R. Yang2; Y.D. Yang3; P. Wu3; A. McLean3; 1Kunming University of Science and Technology - and - University of Toronto; 2Kunming University of Science and Technology; 3University of Toronto A considerable amount of waste slag from the pyrite roasting process is discharged every year. Recovery of iron from the waste slag is of great interest for comprehensive use of mineral resource, reduction of environment impact and improvement of economical benefit to related companies. The objectives of the present work are focused on: (1) Compare various procedures for recovery of iron from the waste slag and select a best procedure for industrial trial which is roasting of the waste slag under reducing condition followed by magnetic separation; (2) Investigate the optimum conditions for maximum recovery of iron from the waste slag. The experimental result shows that under the treatment condition found in this work about 36 to 40% of the iron oxide was recovered from the waste slag, where the iron content in the concentrate is 57%. The total recovery ratio of iron, up to 70%, from the waste slag was achieved. After the treatment, sulphur content in the waste slag was reduced significantly and gangue materials, such as SiO2, Al2O3 and TiO2, were reduced effectively.

10:35 AMStabilization of Chromium-Based Slags with FeS2 and FeSO4: Antonio Romero-Serrano1; Guadalupe Diaz-Sandi1; Marco Pineda-Rivera1; Beatriz Zeifert1; Carmen Martinez-Morales1; Hugo Martinez-Gutierrez1; 1IPN Chromium containing slags from stainless steelmaking may eventually be leached by acidic environments, therefore they should be treated before being stockpiled or land filled. In this work, synthetic chromium-based slags were prepared and the effect of the slag basicity (CaO/SiO2), FeS2 and FeSO4 contents on the stability of the mineralogical species formed was analyzed. The morphology and composition of the slags were analyzed by XRD and SEM-EDS, whilst their chemical stability was evaluated by leaching with an aqueous acetic acid solution. It was found that in slags with CaO/SiO2 = 1, the main Cr-compound was FeCr2O4 spinel. The slags with CaO/SiO2 = 2 mainly formed CaCr2O4 and CaCrO4 compounds. The results showed that the highest Cr concentration levels in the leaching liquors corresponded to slags with CaO/SiO2 = 2. It was also observed that the lowest Cr concentration levels in the leaching liquors corresponded to slags with low basicity and high contents of FeS2 or FeSO4 owing to the stable binding of chromium in FeCr2O4 spinel.

11:00 AMValorisation of Thermal Residues by Intensified Mineral Carbonation: Rafael Santos1; Da Ling1; Muxing Guo1; Bart Blanpain1; Tom Van Gerven1; 1Katholieke Universiteit Leuven Mineral carbonation involves the capture of carbon dioxide in a mineral form. The principal aim and advantage of this approach is the chemical stability and storage safety of mineral carbonates, the opportunities for process integration presented by the technology and the potential for valorisation of otherwise low-value resources (virgin or waste) into useful products. The main barriers to its deployment in industry are: high energy intensity, low reaction conversion, slow reaction kinetics, complexities of the production chain, process adaptability, and competition for attention with alternative carbon capture technologies. A class of waste materials that has good potential for implementation as a feed material for mineral carbonation are steel slags. Treatment and disposal of these slags can be a costly burden on steel plants. Sustainable solutions for Argon Oxygen Decarbonisation (AOD) and Continuous Casting (CC) stainless steel slags and Basic Oxygen Furnace (BOF) steel slag are still to be found. An integrated on-site mineral carbonation approach is envisaged as a possibly economically favorable solution. In this work, the one-stage carbonation

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process is chosen for investigation of carbonation of AOD, CC and BOF slags. Two experimental approaches are tested: carbonation in slurry phase (gas-solid-liquid) and carbonation of at high temperature (gas-solid). The main goals were to (i) sequester the maximal amount of CO2 under optimal conditions, (ii) stabilize free lime and leaching properties of the waste material, and (iii) find the most appropriate carbonation method for industrial implementation and to produce a valorized product. Several process parameters that influence carbonation were studied, such as temperature, pressure, particle size and mineralogy.

11:25 AMPyrometallurgical Treatment of Flue Dust from Copper Smelters for Stabilization of Va Elements and Cu Recovery: Roberto Parra1; Eduardo Balladares1; Igor Wilkomirsky1; Fernando Parada1; Ignacio Saavedra2; Juan Alex Carrasco3; Roberto Parada4; 1Universidad de Concepción; 2New Tech Agro; 3Xstrata Copper; 4Anglo American PLC In most of the smelters, the management of flue dust has a double objective: the control of minor elements in the anodes and the management of volatiles compounds that can cause contamination due to fugitive gas emissions. This is a special concern when high content of Va elements (As, Sb & Bi) are present in concentrates. We present the results of the experimental study to prove the principle of a novel process that recovers, via volatilization, the As, Sb and Bi in the flue dust as sulfides gaseous compounds, due to a previous sulphidization. In the case of As control, the gas collect it, and any further classical treatment for its stabilization is possible. The clean calcine can be returned to the smelter avoiding any concentration of these minor elements in the circuit. This process is now tested at pilot scale and shows better indices on carbon footprint than the classical hydrometallurgical process for flue dust.

11:50 AMA Mathematical Model for Carbothermic Reduction of Dust-carbon Composite Agglomerates: Yuki Kuwauchi1; Mansoor Barati1; 1University of Toronto Recycling of iron-bearing wastes from steel mills has gained a considerable attention in the past two decades to recover the secondary iron values while reducing environmental impact of steelmaking. Reduction of the dust in the form of dust-carbon pellet or briquette using a rotary hearth furnace (RHF) has been successfully practiced. However, its process and product control have proved to be demanding tasks due to the unpredictability of the reaction behaviour of the dust-carbon composite, which is attributed to the following two reasons. First, within the composite pellet, iron oxide reduction and carbon gasification reactions take place simultaneously, while their extent and rate are greatly affected by other variable components of dust. Secondly, unlike iron ore, the composite contains considerable amount of zinc, carbon and other gangue materials; thus, the reactions are reciprocally affected and all three phases and their interactions should be considered within the composite. In other words, each pellet acts as a micro reactor. In order to predict the reaction behaviour of the dust-carbon composites, a mathematical model was developed. The model takes into consideration the rates of reduction for iron and zinc oxides and carbon gasification as well as the influence of the slag components and phase change on the reactions. The model was validated with experimental results and it can be utilized as a process designing tool for the dust recycling using RHFs. Some calculation outputs and findings specific to the dust-related reactions will be presented.

WORLD GOLD: Environment

Tuesday AM Room: Fontaine DOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Terrence Chatwin, INAP

9:30 AMAssessment of Acid Rock Drainage and Metal Leaching Risks at Barrick Gold Corporation: Bill Williams1; Bill Upton1; 1Barrick Gold Corporation Barrick Gold Corporation is the gold industry leader, with 25 operating mines and a pipeline of large, long-life projects located across five continents, in addition to large land positions on some of the most prolific mineral districts. Barrick?s high level of commitment to sustainable economic development, environmental stewardship was recognized by Dow Jones Sustainability Index (DJSI) ? World, for the third consecutive year in 2010. The potential for adverse environmental effects from acid rock drainage (ARD) and metals leaching (ML) and their financial implications for Barrick are key considerations in our environmental assessment and business development processes. Barrick?s membership in the International Network for Acid Prevention (INAP) reflects the importance of these issues to our business. INAP?s development of the GARDGuide (a best practices guide for acid rock drainage prevention) provides Barrick with an important tool to assist in the assessment of environmental and financial risks from ARD and ML associated with our planned and ongoing mining operations. In this paper we will discuss how Barrick incorporates the GARDGuide and its principles for ARD and ML prediction and prevention in our business development processes and the management of our operations. The GARDGuide serves as a key reference for our project environmental assessments and as common link between our projects and operations management, consulting specialists, permitting and regulatory authorities and the public. We will discuss how the GARDGuide is being ?syndicated? throughout Barrick as a standard of practice and present a case study of how it was used in recent Barrick Business Development Project.

9:55 AMProactive Mineral Waste and Acid Rock Drainage Management at Rio Tinto: Rich Borden1; 1Rio Tinto Rio Tinto is a diversified mining company that manages copper, iron, nickel, diamond, coal, gold and industrial minerals operations across the world. Many of these ore bodies pose acid rock drainage (ARD) risks and Rio Tinto is committed to proactive mineral waste and ARD management. Corporate requirements are closely aligned with the GARD Guide principles of early geochemical characterization and prediction followed by selection and implementation of management strategies to prevent or minimize ARD. Rio Tinto has had mandatory internal standards and guidance notes addressing ARD and mineral waste management since 2003. An ARD risk review program which brings internal and external technical expertise to higher risk operations has been running since 2004. In 2009 a formal mineral waste strategy for the company was developed which is focused on chemically reactive wastes and which includes a corporate statement of principles on mineral waste management. Each operation is required to design and implement an ARD and Mineral Waste Management Plan. These plans must include background on the geochemical behavior of the mineral waste, management strategies to prevent or control the geochemical risks, accountabilities for implementation of the plan and monitoring programs needed to ensure the strategies are working as designed. Successful implementation of the plan requires commitment and cooperation at all levels of the company, from senior management, to geologists, mine planners, environmental staff and equipment operators. Examples of the successful integration of ARD management strategies into mine operations and closure plans are cited from several projects and mines.

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10:35 AMApplication of Standardized Net Carbonate Value Characterization Methods to GARD Guide Implementation: Charles Bucknam1; 1Newmont Metallurgical Services Net carbonate value (NCV) characterization methods for acid generation potential measurement originated from studies on the Carlin Trend during the 1990’s and have been subsequently standardized through cooperation of the Acid Drainage Technology Initiative Metal Mining Sector and the American Society of Testing and Materials International. The paper describes the evolution and standardization of the NCV methods, the importance of mineralogy in interpreting the results and application of the methods to implementation of the Global Acid Rock Drainage (GARD) Guide.

11:00 AMAchieving Stakeholder Support for New Gold Developments that Contain Sulphide Minerals: Jim Robertson1; Terrence Chatwin2; Rens Verburg3; 1Detour Gold; 2INAP; 3Golder Associates Inc. While jobs and economics are one of the major incentives for a community to support a mine in their vicinity, local stakeholders must also be assured that the environment will be protected. Mining companies can help achieve stakeholder support for a new mine containing potentially leachable materials by presenting and addressing Acid Rock Drainage (ARD) issues from a sustainable development perspective. Decades of research and experience in mining sulphide ore bodies have resulted in the development of reliable methods for predicting and preventing ARD. To prevent ARD, miners must begin early in the mine life-cycle to develop an ARD management plan and integrate it into the mining operations. As this proactive preventative program is initiated, mining companies also need to engage, inform and collaborate with stakeholders to insure that the plan meets the expectations and objectives of all. Stakeholders’ engagement is enhanced and credibility gained as mining companies develop an integrated and responsible approach that accounts for short- and long-term environmental, social and economic issues, and emphasizes the importance of clean and available water for current and future generations. In this paper, examples of effective ARD prevention will be presented within a sustainable development context.

WORLD GOLD: Gravity Recovery

Tuesday AM Room: Hampstead / Cote St. LucOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Y. Choi, Barrick Gold

9:30 AMGravity Gold Concentration at Newmont Mining: Aidan Giblett1; 1Newmont Mining Corporation The process of gold recovery by gravity concentration is incorporated in the metal recovery flowsheet at seven Newmont Mining Corporation owned mining operations in Australia, North America and Africa. In 2009 gold recovered by gravity processing was equivalent to nine percent of Newmont’s total gold sales of 5.3 million ounces. This paper will discuss these applications in detail including a review of plant flowsheets and presentation of recent operating results. Operating performance will be discussed with reference to ore characterisation procedures, interpretation of results, design considerations and optimisation practices as they relate to the recovery of gold by gravity concentration.

9:55 AMOptimising Circuit Design for Gravity Gold Recovery: William Staunton1; Alan Bax1; 1Curtin University of Technology To determine the optimal circuit configuration for gravity gold recovery consideration should be given to a range of factors in addition to the efficiency of the gravity circuit, including capital costs, ease of operation

and impact on comminution. The most common gravity gold circuits utilise a centrifugal concentrator treating a portion of the cyclone underflow. This paper will examine this option and alternative circuit configurations to illustrate the effect of various gravity circuit feed and tailings configurations on the equipment sizing, capital costs, operating costs, water balance, comminution efficiency and gravity gold recovery. The optimum circuit configuration can provide reduced capital and operating costs, maximise gravity gold recovery and improve comminution efficiency.

10:35 AMEvolution of Gold Gravity Recovery in Grinding Circuits - A Critical Review: Sunil Koppalkar1; Ahmed Bouajila1; Claude Gagnon1; Sami Makni1; 1COREM Gold recovery within grinding circuits has evolved tremendously with the development of enhanced gravity separation technology. This paper reviews briefly the gravity recovery practices involving conventional gravity separators, operated at natural gravitational force, and semi-continuous centrifugal gravity separators that operate at 60 times the gravitational force or more. The evolution and advantages of semi-continuous gravity separators will be discussed. Techniques for further upgrading the gravity concentrates obtained will be dealt with briefly, as for example the “reinvention” of the intensive cyanidation technique as a supplement or as an alternative to the “not-so-efficient” tabling operations. The research efforts that were deployed in optimizing semi-continuous gold gravity separation will be recalled. The use of continuous centrifugal gravity separators, primarily aimed at recovering gold carriers, in combination with semi-continuous machines will also be addressed. Finally, innovative gravity circuit configurations for eliminating or minimizing the use of complex processing schemes involving costly reagents will be reviewed. On-going research at COREM to understand the discrepancies between predicted and actual plant GRG recoveries has revealed that gold particle shape transformation is the main factor explaining the lower gravity recoveries of the plant units. Efforts to devise possible remedies for improving gravity recovery at plant scale will be presented.

WORLD GOLD: Technological Developments/Cyanide

Tuesday AM Room: Mont RoyalOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: J. Bouchard, GENIVAR

9:30 AMImproving the Economics of Gold-Copper Ore Projects Using SART Technology: R. Lawrence1; O. López1; 1BioteQ Environmental Technologies Many gold deposits in the world have not been developed due to the presence of copper and other base metals which can cause metallurgical and environmental challenges due to the formation of base metal cyanide complexes. SART technology (sulphidization-acidification-recycle-thickening) can resolve these issues by recovering copper as a high grade sulphide concentrate, recycling the associated cyanide back to the gold leach, and eliminating the downstream environmental liabilities. Project economics can be improved substantially leading to a positive re-evaluation of new and existing gold-copper projects. Some aspects of the design and operation of two recently commissioned SART plants will be discussed.

9:55 AMComparing Refractory Gold Ore Pre-Oxidation and Crushing Options Using MINTEK’s Advanced Leach Facility: Sonestie Janse van Rensburg1; Sunny Zhang1; 1MINTEK MINTEK has established and validated an Advanced Leach Facility (ALF) as a tool to record detailed kinetic leach information aimed at refractory sulphide ores. Immense competition for resources such as water

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and arable land has refocused attention on water and tailings management with respect to quantity and quality. As it makes more sense to tackle problem issues at source, there exists a strong need for additional leach process information to be generated that enable proactive decision making. Instead of focussing only on gold and gold recovery, the impacts of different pre-oxidation methodologies were evaluated also taking into consideration the sustainability parameters, (cyanide speciation and consumption, thiocyanate formation, arsenic liberation from arsenopyrite, heavy metals dissolution, high salt loads, overall process water quality, resulting residue stability), ensuring a holistic process view. Results of duplicate refractory gold leaches comparing bio-oxidation, oxygen pre-oxidation, ozone pre-oxidation, ultra fine grinding, high pressure grind rolls, high shear and pressure oxidation are presented in conjunction with a relative capital and operating cost comparison. The environmental and sustainability effects associated with each of these technologies are outlined. Keywords: Arsenic, cyanidation, oxidation, sulphide ores, environmental

10:35 AMImprovements in Leaching of Gold and Silver from Sulphide Ore from Mexico with the Celp: Guy Deschênes1; Mike Fulton1; 1Natural Resources Canada An open-pit mine, located in Mexico, processes an ore averaging 0.35 g/t Au and 80 g/t Ag at a rate of 4000 tpd. Conventional cyanidation is used (2400 ppm NaCN) to extract gold and silver. Cyanide is recycled using AVR (Acidification-Volatilization-Recycling) to reduce the environmental impact, cyanide consumption and reclamation costs and copper is recovered from the cyanide solution by electrolysis. A laboratory study was conducted to increase silver extraction and to reduce the concentration of cyanide in leaching. The sample contained 0.41 g/t Au, 125 g/t Ag, 0.73% S, 1.64% Fe, 0.52% Zn, 0.030% Cu and traces of Sb and As. The mineralogical analysis showed the presence of 99% gangue minerals, pyrite at 0.7%, 0.07% sphalerite, chalcocite at 0.03% and 0.01% galena. The plant conditions (2400 ppm NaCN, pH 11.3, 96 hours leaching) produced 90.2% gold extraction (leach residue at 0.04 g/t Au) and 92.7% silver extraction (leach residue at 9.1 g/t Ag) on a sample with a P80 of 86 microns. The CELP (CANMET Enhanced Leaching Process), using the same retention time that the plant and 500 ppm NaCN produced 97.0% silver extraction (leach residue at 3.8 g/t) and 90.2% gold extraction. The incremental gross revenue was estimated at $US7.6 million and the reduction of cyanide costs was $2.9 million per year (79%). Silver leaching kinetics with the CELP were faster than the plant leaching conditions.

11:00 AMCyanide Leaching of Gold-Copper Porphyries: Chemistry and Challenges: Chris Fleming1; Michael Botz2; Kevan Ford; 1Kinross Gold; 2Elbow Creek Engineering In recent years, there has been an increase in the number of projects where processing of metallurgically complex, low-grade gold ores is conducted. This results from a decline in the availability of large free-milling oxide ore bodies where high gold extractions can be accomplished with relative ease. Porphyry ores are frequently a source of low-grade gold ore, but gold in these ores is often associated with significant levels of cyanide-soluble base metals, especially copper. Cyanide leaching of such ores increases flowsheet complexity, operating costs and requires planning to satisfy environmental requirements for tailings disposal and mine closure. Cyanide leaching of gold-copper porphyry ores typically results in leach solutions with elevated levels of copper, and possibly other metals such as cadmium, mercury, nickel and zinc. Dealing with these ores under heap or agitated tank leach conditions requires a thorough understanding of ore mineralogy and process chemistry in order to maximize efficiency of gold extraction and recovery. In many cases, the continuous removal of cyanide-soluble copper and other metals from leach solution is necessary to limit their build-up with time. Build-up of these metals can significantly affect gold recovery onto activated carbon and prohibitively increase the consumption of cyanide. Removal of cyanide-soluble metals from leach solution will result in the regeneration of free cyanide, and yield by-product metals

with potential sales value. This paper reviews the chemistry of cyanide leaching of gold-copper porphyry ores, with focus on the cyanide leach process, carbon adsorption phenomena and means of removing base metals from leach solutions. Primary economic drivers behind the processing of such complex ores are also analyzed. Data from mine operations and development testwork conducted on gold-copper porphyry ores in Chile are presented to support discussion on the chemistry and challenges facing the gold sector in cyanide processing of complex ores.

LIGHT METALS: Aluminium Production III

Tuesday PM Room: LachineOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Marc Dupuis, GeniSim; Abdelkader Baggag, Aluminium Research Centre - REGAL, University Laval

2:00 PMP155 Cell Start-Up Thermal Electrical Mechanical Slice Model Including Sodium Expansion Effect: Lyès Hacini1; Jean-François Bilodeau1; Yves Caratini1; 1Rio Tinto Alcan Independently of the technology, the start-up is the most critical phase of the cell life, as an uncontrolled start-up could lead to early infiltrations, instabilities, and in some cases to the cell death. Lots of efforts are put to increase the lifespan of cells, as it has a major impact on both the operating costs and the environmental footprint of the aluminum industry. Obviously, true size test on a cell is resources and time consuming approach that could be used only to validate mature concepts. Moreover, numerical modeling is a low cost and versatile tool capable to test a wide range of potential ideas and concepts. In the present article a thermal electrical mechanical slice model is presented. This model describes the preheating period of a P155 aluminum cell start-up, as used at the Grande Baie smelter.This model will be useful to study different problematical issues such as the global behaviour of lining materials, shell and cradle deformations during start-up and several start-up scenarios. Such model will also be able to answer some interrogations regarding early infiltrations and their impact on the lifespan of the electrolysis cell.

2:25 PM InvitedRio Tinto Alcan – Recent Developments from AP60 Jonquiere Plant, Quebec: Francois Charmier1; 1Rio Tinto Alcan The paper provides the most recent information on the construction of the AP60 Phase 1 Plant of Jonquière which is due to be commissioned and started up in the first Quarter of 2013. HSE management on site by RTA, and cooperation with local equipment manufacturers and contractors of the Saguenay-Lac Saint Jean region are highlighted in this section. The AP60 Phase 1 Jonquière Plant aims at the demonstration of the AP60 Technology at the industrial scale and allows the further developments of the AP60 cell. The advantages of the AP60 cell technology in terms of productivity, power consumption and environmental footprint are also briefly presented in the paper.

2:50 PMInvestigation of the Increase in Resistivity in the Steel Collector Bar Used in Aluminum Electrolysis Cells: Guillaume Gauvin1; Daniel Larouche1; Denis Laroche2; Mario Fafard1; 1Laval University; 2Rio Tinto Alcan Life span of aluminum smelting electrolysis cells can reach up to 3000 days. During this period, cathode blocks go under various physical and chemical changes that could result in an increase of electrical resistivity. The increase may be due to carbon migration from the cast iron to the steel bars, gap evolution between the cathode block and the cast iron, cathode cracking, etc. This paper focuses however only on the collector steel bar electrical resistivity evolution. To reveal the main phenomena responsible for the electrical resistivity increase, chemical analysis, metallographic

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and electrical resistivity tests were conducted on two steels bars picked from two Hall-Héroult cells after autopsies. Cathode voltage drop and temperature were measured using electrically insulated internal probes and thermocouples on 16 samples from each steel bar. Electrical resistivity can reach up to 1.21µO-m for a steel bar aged 2505 days compare to 0.142µO-m for steel AISI 1008 at room temperature.

3:15 PMTowards a Probe to Determine the Direction of Velocity in Liquid Aluminum: Mitren Sukhram1; Stavros Argyropoulos1; 1University of Toronto This paper presents a technique to determine the direction of velocity in liquid aluminum (Al) by measuring the temperature distribution within a cylindrical rod while it is inserted into the flow. The heating pattern of the rod is a result of the interaction of the thermal fields of the rod with the liquid Al. This interaction freezes aluminum onto the cylinder in a characteristic pattern and as a result the temperature response within the rod also follows a distinctive heating pattern. Monitoring the temperature within the cylindrical rod as a function of spatial and temporal coordinates, the direction of velocity can be inferred. Experimental research work involving liquid Al was conducted at the University of Toronto using the Revolving Liquid Metal Tank (RLMT). The RLMT is a resistance furnace which can hold up to 50kg of liquid Al. In this RLMT tangential velocities up to 0.35m/s can be generated. Experimental data for different superheat and magnitude of velocity demonstrate that the sensor records different heating patterns under different fluid flow conditions. Using the transient temperature information, the direction of velocity of the molten Al flow field can be detected.

3:55 PMThe Riotinto’s P155 Smelters Now Operating at 210 KA: V. Gaudreault1; H. Vermette1; Valérie Langlois1; Louis Lefrançois2; 1Rio Tinto Alcan - CRDA; 2Rio Tinto Alcan - UGB Rio Tinto Alcan (RTA) has three smelters that use the Alcoa P155 technology: two in Canada (Grande-Baie and Laterrière, Saguenay, QC) and one in the United States (Sebree, Kentucky). The oldest RTA P155 smelter was built in the 1970s (Sebree) and had an initial current intensity of 155 kA. In the 1990s, RTA installed an amperage booster in Grande-Baie smelter to increase cell productivity. Since then, RTA has continuously pushed the limit of this technology and the target amperage that was 195 kA in 2005 has been increased to 210 kA in 2010. This article describes the successful plant-scale trials to increase current intensity from 195 kA to 210 kA, and the key performance indicator results. It demonstrates RTA’s technology leadership to undertake such a development with its Brownfield smelters.

4:20 PMThermal Conductivity of Anode Cover Materials in Hall Heroult Cells: Hasini Wijayaratne1; Margaret Hyland1; Mark Taylor1; Andreea Grama1; Tina Su1; 1University of Auckland Anode cover material, a mixture of crushed electrolyte and alumina, is a crucial part of an aluminium reduction cell because of its important role in maintaining overall heat balance. However, until recently little attention has been given to understanding or controlling its composition and quality. The thermal conductivity of anode cover material determines the extent of the heat loss from the top of the cell. This will change as a function of the granulometry and composition of the applied cover as well as over time as the cover material consolidates on top of the cell. The ability to measure or predict the thermal conductivity of fresh and ageing cover is an important tool for managing cell heat balance. Recent studies have shown that granulometry or more correctly, voidage is likely to be the predominant determinant of thermal conductivity of anode cover materials. We have developed equipment to measure the thermal conductivity of granular cover material and tested the relative importance of composition (ratio of alumina to crushed electrolyte) and granulometry/voidage on cover thermal conductivity. In general, our results confirm that granulometry is the dominating factor. Generally, high voidages contribute to lowering the

thermal conductivity especially when particles are mostly fine. However the relationships between granulometry, voidage and thermal conductivity are complex due to the varying nature of heat transfer between particles. Aging of granular cover material occur during cell operation forming a consolidated crust due to exposure to heat and fumes over time. Structure and thermal behaviour of this consolidated crust is also important in understanding the overall properties of cover. This paper presents the outcomes of laboratory studies conducted in order to understand the thermochemical behaviour of anode cover material and in particular, the role of fines in anode covers mixtures.

LIGHT METALS: Aluminium Transformation II

Tuesday PM Room: LasalleOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Mahi Sahoo, Suraja Consulting; Victor Songmene, Aluminium Research Centre - REGAL, Ecole de technologie superiere

2:00 PMCorrosion Behavior of Al-B4C Metal Matrix Composites in H3BO3, K2SO4 and NaCl Solutions: YuMei Han1; Danick Gallant2; X. Grant Chen1; 1University of Quebec at Chicoutimi; 2National Research Council Canada The corrosion behaviour of Al-B4C metal matrix composites immersed in 2500 ppm boron-containing H3BO3, 0.5 M K2SO4, and 3.5% NaCl solutions was investigated. Effects of B4C particle volume fraction on the corrosion behaviour of composites were studied using potentiodynamic polarization and electrochemical impedance spectroscopy techniques. Scanning electron microscopy was employed to study the surface morphology of the material before and after corrosion. Results show that all materials investigated are more corrosion resistant in 2500 ppm boron-containing H3BO3 than in other solutions. No appreciable corrosion was observed in boric acid and sulfate solutions in contrast to an obvious pitting in NaCl solution for both base alloy and composites. The preferential pitting sites are the interfaces of Al/Fe intermetallics for the base alloy, and the Al/B4C interfaces for the composites. Increasing the volume fraction of B4C particles in the composite decreases its corrosion resistance of Al-B4C composites.

2:25 PMCorrosion Behaviour of the Forged AA6082 Aluminum Alloy from Different Feedstock: Pascal Gauthier1; Martin Fortier2; Edward Ghali3; André Charette1; X. Grant Chen1; 1Université du Québec à Chicoutimi; 2Rio Tinto Alcan Inc; 3Université Laval Current feedstock in the aluminum hot forging processes can be used in the cast or extruded forms. The microstructural variation between as-cast and extruded materials could result in different mechanical properties and corrosion resistance for hot-forged products. Corrosion performances were examined for forged parts produced by two AA6082 feedstocks at different conditions using the following corrosion tests: open circuit potential, anodic polarization, salt spray exposure and corrosion fatigue. With the help of optical and scanning electron microscopes, metallographical investigations were carried out on cast-forged and extruded-forged materials before and after corrosion. The corrosion behavior of both materials was compared in both as-forged and aged tempers. Results show that there is no significant difference in the corrosion performance for final cast-forged and extruded-forged products.

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2:50 PMDevelopment of Hypereutectic Al-Si Casting Alloys with Variable Mg Content: Alireza Hekmat-Arkakan1; Frank Ajersch2; X.G. Chen3; M. Tebib3; 1Universite de Sherbrooke; 2Ecole Polytechnique; 3Universite du Quebec a Chicoutimi Conventional hypereutectic Al-Si alloys such as A390 are used principally for the casting of components used in wear applications requiring abrasive resistance such as in engine or compressor blocks. A comprehensive study was undertaken to investigate the potential of improving the mechanical properties of these alloys by the addition of magnesium. A thorough thermodynamic study of the effect of the addition of Mg to the conventional A390 alloy showed that Mg2Si starts to form as a primary phase at 4.2% Mg as well as in the products of the binary and ternary eutectic reactions forming the matrix. Experiments were carried out in producing castings with different cooling and solidification rates of alloys with up to 10% Mg. Mg additions were found to increase the hardness over the as cast alloy due to solid solution strengthening. Also, T6 heat treatment greatly improved the tensile properties of these alloy compositions due to the strengthening effect of the theta-Al2Cu phase. The elongation of these alloys generally decreases marginally with Mg content. The most significant property improvement of the alloys with higher Mg content is the substantial increase in wear resistance. This is attributed to the dispersion of smaller particles of Mg2Si and their coherence with the matrix as compared to the large Si particles in the conventional alloy. A new rheoforming process for A390 is presented that improves the processing of the semi-solid slurry. Structure modification elements were also added to refine the primary and eutectic silicon greatly improving the processing of the semi-solid slurry.

3:15 PMDissolution Studies of Si Metal in Liquid Al with Gas Injection: Mehran Seyed Ahmadi1; Stavros Argyropoulos1; Markus Bussmann1; Don Doutre2; 1University of Toronto; 2Novelis Global Technology Center This study investigates the role of nitrogen gas injection in the dissolution rate of Si into liquid Al. A unique revolving liquid metal tank was used, with a capacity of 50 kg of liquid Al. Experiments without gas injection have shown that the dissolution of Si increases as the bath superheat and the tangential velocity of the liquid Al increase. When injecting nitrogen gas at flow rates between 0-5 lit/min in the vicinity of the solid Si, results so far clearly show greater dissolution. In addition, results on the role of the gas flow rate relative to the position of the nozzle are presented and analyzed.

3:55 PMExperimental Design Approach to the Effects of Chemical Composition on the Mechanical Properties and Machinability of Near-Eutectic AL-11%Si Casting Alloys: Yasser Zedan1; A.M. Samue2; F.H. Samuel2; A.M.A. Al Ahmari3; 1ETS; 2UQAC; 3King Saud University In the present study, statistical design of experimental (DOE) has been applied to study and control the properties of near-eutectic Al-11%Si alloys and develop regression equations between response variable including hardness, yield stress, ultimate tensile stress, elongation, total cutting force, cutting power, and tool life and the factors varied which include percentage composition of the alloying element and modification level. These equations may be analyzed quantitatively to acquire an understating of the effects the main variable and their interactions on the mechanical behviour and the machinability of the alloy under investigation. Analysis of variance (ANOVA) has been performed to verify the fit and adequacy of the developed mathematical models. The results show that increasing level of Cu and Fe contents results in an increase in hardness, yielding stress and ultimate tensile strength in both modified and non-modified alloys. On the other hand, both Cu and Fe appear to affect the elongation adversely while the Sr-level shows a positive effect on the percentage elongation. It was

found that the Sr-level has the most significant effect on the cutting forces and cutting power followed by Fe and Cu-contents. The results also show that the interaction coefficients of these variables have the significant effect on the tool life in comparison to main independent variables. This fact may be attributed to the formation of complex insoluble phases between Cu, Fe, Si, and Al as investigated using Scanning Electron Microscopy (SEM) attached to an EDX analysis. The accuracy of the regression equations in predicting the properties has been verified by carrying out random experiments in the range of variation of these variables.

4:20 PMOn Particle Emission during Machining of Titanium and Aluminum Alloys: Riad Khettabi1; Yasser Zedan1; Jacques Masounave1; Victor Songmene1; 1École de technologie supérieure, ÉTS The mechanical, thermal and bioproperties of titanium alloys allow their wide use in different industries. Compared to aluminum alloys, titanium alloys are very tough, making them that much more difficult to machine than aluminum alloys. Most studies conducted on these types of materials have mainly covered and made comparisons in terms of cutting speed, cutting force and mechanical properties. Recently however, their sustainability and environment parameters have begun to attract significant interest, and it has been found that machining processes generate particles that can be harmful for health and the environment. In this paper, particle emission is investigated during the turning of the titanium Ti6Al4V and 6061-T6 aluminum alloys.

4:45 PMRecycling of Aluminum Alloy by Direct Convertion Method of Cutting Chips and Its Mechanical Properties: Harun Mindivan1; Recep Vatansever2; Eyup Kayali3; 1Ataturk University; 2 Istanbul Technical University; 3Istanbul Technical University In the present study, the feasibility of recycling AA6061 Al alloy chips by a combination of cryomilling, cold compaction and hot extrusion processes was investigated. Furthermore, the effect of Al powder addition to the recycled Al alloys chips on the mechanical properties was investigated. The characterization of recycled Al alloys was made by structural examination and mechanical tests (hardness, compression and dry sliding wear tests). The results indicated that by increasing wt. % of Al powder added to the recycled Al alloy chips the studied properties (the density, hardness, compressive strength and wear resistance) increased due to reduction of porosity in the recycled Al alloys.

5:10 PMSurface Quality of 7075-T6 Aluminum Alloy Machined Using High-Speed Milling Process: Rene Kamguem1; V. Songmene1; J. P Kenne1; A. Tahan1; 1Université du Québec The surface of a mechanical part plays an important role in determining performance in service. The presence of scratches left by the cutting or tearing of the material on the surface of the workpiece supports the concentration of stress and strain. This article presents the experimental study for high speed milling of the aluminum alloy 7075-T6, using cutting tools different by the nose radius and coatings (TiCN, TiAlN, TiCN + Al2O3 + TiN). A multi levels factorial design of experiment (DOE) and statistical analysis was used. The roughness parameters investigated are Ra, Rq, Rv, Rc, Rsm and Rk. The results show that the feed rate, the types of coatings and geometry of cutting tools have the major impact on the surface quality. Surface finish charts according to feeds and cutting speeds were established for each tool tested.

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MANAGING THROUGH RECESSION: Managing Through Recession II

Tuesday PM Room: Fontaine GOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Daniel Brosig, Hatch

2:00 PMKeeping Pace with the Times – WorleyParsons Innovations for Lower Capital Mining and Projects: Tony Warner1; Philip Mackey1; Niraj Dave1; Lou Bruno1; 1WorleyParsons Canada The metal and minerals industry has emerged from the recent recession with good prospects for the near and longer term future. Thus the World Economic Forum in Davos this year considered that the world may be entering a new long term growth cycle with some short term disruptions. Current developments in China, India, Brazil and elsewhere appear to support this situation. Amid this situation, unchecked, plant construction costs in future are likely to escalate. By introducing innovations to the engineering and plant design aspects of new mines and metallurgical plants, WorleyParsons, in part learning from the economical downtime, is looking at approaches towards higher quality capital projects with lower capital cost and will review some of these approaches.There are many issues involved in Capital Mining and Metallurgical Projects that might impact CAPEX, OPEX and schedule and become risks to the overall project at the construction or operational stage. WorleyParsons provides services that incorporate consideration of these risks. It is very important to include sustainability assessment at early stage of project development. Some sustainability aspects have a direct impact on project cost as well as other indirect results and will be reviewed. Sustainability and Risk analysis delivery minimises these business and project risks to deliver an optimised outcome.Our company is also looking at new ways to help operating plants contend with higher operating cost, such as keeping higher energy costs in rein. This presentation will explore these topics including a review of modular plant design, construction concepts and the effective use of energy surveys as a step towards lowering unit energy consumption and hence achieving lower costs.

2:25 PMManaging through Economic Cycles - An Engineering and Technology Perspective: Nils Voermann1; 1HATCH Periodic recession, the nadir of the economic cycle, continues to be a fact of business life: Economic down-turns tend to recur rather regularly once a decade or so (2009, 2000, 1991, 1982...). Recessions are painful, but like winter they are also a useful opportunity to prepare for the inevitable following spring and summer. Mining & metals engineering and operating companies alike can use the time of slackened demand to efficiently build their capacity to take advantage of the inevitably following boom times. During recessions, engineering firms can re-assign key staff from implementation projects to research and development of new technologies, writing technical papers, and enhancing their own internal work methods and systems - important activities that tend to have lower priority in boom times. Companies with a sufficiently long-term view also use the opportunity to strengthen the expertise of their organizations, attracting people that may become available from competitors who feel the urgent need to reduce staff costs. Especially given the long time frames for project implementation, operating companies can use the opportunity of lower project costs prevalent in recessions to economically augment their production capacity; the increased capacity is then ready in time for the predictable rebound in metals demand at the recession’s end. Recessions are also an ideal time for maintenance shut-downs or plant rebuilds and upgrades, since the opportunity cost of temporarily lost production is of course much reduced with the low metals prices typically prevalent in recessions. An illustrative example is BHPB’s doubling the capacity of

their Cerro Matoso ferro-nickel plant in the 1998-2000 recession. This expansion was completed just in time to take advantage of the subsequent decade long boom in metals demand and prices.

2:50 PMMining and the Future Industrial Development of the Canadian Shield : michael sudbury1; 1mpscsi The expanding global population and improved standard of living arising out of industrialization of the developing world economies are expected to substantially increase the demand for mining industry, agricultural and forestry products. This increase in demand is expected to benefit Canada as a supplier of metals, minerals, food and wood products. The Canadian Shield may be expected to benefit from the increase in mining activity to supply the expanded demand for metals. Much of the mining activity in the past has been concentrated around the main transportation corridors (roads and railways) where people and power are also available and coincide with favorable mineral potential. Economic expansion on a broader basis will require an improved transportation network and the development of population nodes (communities with good education and health facilities) to attract the people for the efficient operation of high technology mining and mineral processing operations. The development of such ‘nodes’ would be favoured if industrial activity through the Shield could be expanded and diversified. The pressure of increasing global population on the biosphere and particularly the need to increase the productivity of the finite area of prime agricultural land in the world is expected to provide new opportunities for the Canadian Shield. This paper examines in a decadal time frame some of the changes expected to mining practice, what other industrial opportunities may open for the Shield and the potential significance of such development for the mining industry.

3:15 PMThe Global Financial Crisis as a Business Opportunity – Reflections on Xstrata Nickel’s Approach and Outcomes: Shaun Usmar1; 1Xstrata Nickel The global downturn in 2008 driven by the collapse of the sub-prime market and subsequent tightening of credit markets caused nickel prices to drop precipitously to less than 20% of the highs of 2007. Prices deteriorated even further in 2009, reaching levels close to $4.00/lb.Faced with a generational-defining event of the magnitude of the Global Financial Crisis, Xstrata Nickel was confronted with an opportunity to embrace the uncertainty as a galvanizing moment for the business to make decisions that would be impossible to execute in more buoyant times, and that would position the business in the short and longer term in a fundamentally stronger competitive position. With the benefit of hindsight, the timely decisions and courageous delivery of the teams across the nickel business delivered just that – a business transformed from the upper third quartile on the cost curve to the lower second quartile, and a near-term growth pipeline that will more than double production by 2014 while maintaining the competitive cost position. The result has delivered clearer accountability, higher employee engagement and commitment, significant increased shareholder value, and a quiet sense of self-belief and accomplishment in the team.

3:55 PMTitle Not Available: Louis Doyle1; 1TSX Venture Exchange Canada is undeniably a world leader in natural resources - particularly in the mining sector. On Toronto Stock Exchange (TSX) and TSX Venture Exchange (TSXV), mining finance is incredibly strong – and growing stronger every day. Our two exchanges combined are home to over 58% of the world’s public mining companies and we’re the global leader in equity mining finance. Here are some of the many reasons why: Our deep, liquid markets are a key element of one of the world’s most sound economic environments; Our unique two-tier market structure accommodates earlier stage exploration companies right through to the most mature producers; Our mining issuers benefit from a flexible system for going public with listing requirements tailored to a company’s stage of development, financial performance and operational resources; We provide our mining issuers with unprecedented support to help inform decisions, navigate the listing

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process, and adjust to life as a public company; The strength of Canada’s mining advisory environment is unparalleled and includes over 200 equity research analysts covering the sector; Our mining issuers have benefited from strong liquidity, superior access to capital, visibility for transactions, analyst coverage and access to specialized indices……even through the recent market downturn. Our growing dominance in the mining sector is not surprising, but it’s not something we’re prepared to take for granted either. It’ is a key leadership sector for Canada, as well as for our exchange group, and it’s a compelling story that we are proud to share with you.

MATERIALS - INNOVATIONS IN JOINING OF ADVANCED MATERIALS: MicroWelding Processes

Tuesday PM Room: LongueuilOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Arnaud Weck, University of Ottawa

2:00 PMRapid Solidification of Al-Ni Alloys by Electrospark Deposition: Gilberto Portillo1; Mathieu Brochu1; 1McGill University Electrospark Deposition (ESD) is a pulsed-arc micro-welding process characterized by using high current electrical pulses, of a short duration, to deposit an electrode material on a metallic substrate. The short duration of the electrical pulse allows for a low heat input over the substrate and an extremely rapid solidification of the deposited material. As a result, the ESD is capable of a wide variety of microstructures like micro-segregation-free solid solutions, nanostructured grains, metastable structures, and amorphous phases. The present work shows a microstructural analysis of rapidly solidified Al-Ni alloys coatings by the ESD process. Field Emission Scanning Electron Microscopy (FE-SEM) and X-Ray Diffraction (XRD) were performed to present the microstructural evolution as a function of the welding parameters. The phases and non-equilibrium metastable structures present in the alloys, and their distribution, were found to be a sensitive function of the alloy composition; hence its formation is governed primarily by thermodynamic considerations.

2:25 PMElectrospark Deposition as a Technique to Repair Damaged MCrAlY Coatings: Rabab Farhat1; Mathieu Brochu1; 1McGill University Coating systems that yield a thermally grown oxide (TGO) protective layer have been proposed as a potential method for extending the lifecycle of components exposed to high temperature corrosion. This is particularly relevant to the petrochemical industry, where any reduction in corrosion rates can yield substantial cost reductions. The primary goal of this project is to develop a coating repair procedure and to investigate the oxidation performance of the repaired location. Electrospark deposition (ESD) was used to repair spalled segments of TGO grown on MCrAlY substrates using various electrodes possessing mixed crystal structures. Specifically, electrodes of NiCoCrAlY (BCC-FCC mixtures) and CoNiCrAlY (FCC- BCC mixtures), were deposited and oxidized to develop the TGO using a heat treatment of 24 hours at 1000°C in air. This presentation will focus on the microstructural evolution of the base metal and ESD repair on damaged area, in both as- deposited and oxidized forms. Results of SEM and XRD analysis will be presented.

NEW TECHNOLOGY IMPLEMENTATION IN METALLURGICAL PROCESSES: Scale-up

Tuesday PM Room: Fontaine HOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: John Peacey, Queens University

1:35 PMIncremental Scale Up of Isasmelt™ - The Key to Its Success: Philip Arthur1; Gerardo Alvear Flores1; 1Xstrata Technology Development of a new smelting process is risky. Many novel processes in the metals industry failed to fulfil the initial expectations of their inventors. Large sums of capital have been invested in technologies that either didn’t provide a satisfactory return on investment, or didn’t perform at all, and had to be replaced. One of the keys to success in process development is incremental scale up of the technology, with potential problems being identified and rectified as early as possible. In this way the cost of any rectification that is required can be minimised. The ISASMELT™ top submerged lance (TSL) process is a good example of a metallurgical process that was developed using incremental scale up. The ISASMELT™ process was developed to maturity by Mount Isa Mines through the 1980’s and 1990’s. The aim was to use the technology to improve the efficiency and environmental performance of the copper and lead smelters at Mount Isa as well as to explore its use for other applications. Commercialisation only occurred once the process had been proven on laboratory, pilot and demonstration scale over many years. Xstrata Technology have as a result installed ISASMELT™ technology successfully at numerous plants around the world. The methodical approach to development of the technology has allowed owners to modernise their existing operations or create new businesses with minimal technical risk.

2:00 PMTeaching Scale-Up to Undergraduates - Drawing on 50+ Years of Engineering-Consulting: Robert Harrison1; Kristian Waters2; Marie-Christine Patoine1; 1Hatch; 2McGill University This paper describes a collaboration between McGill University and Hatch Ltd. to expose undergraduate students to real-world industrial projects. As part of the final-year design course, the students receive a detailed lecture on ‘Scale-Up of New Technologies’, including seven case studies drawn from over fifty years of full-scale industrial projects. The students are taught the basic concepts of scale-up, including the limits of pure theory and the need for empiricism. Insights from real scale-up failures and successes are fictionalized as Projects A, B, C, etc. The students are then asked to identify the guiding principles that can be distilled from these case studies.

2:25 PMA Rheometallurgical Approach to Liquid-Solid Separation: Alex Mezei1; 1SGS Mineral Services Liquid-solid separation and slurry handleability relate directly to commercial plant ramp-up success or lack thereof. The paper provides a well-proven approach for testing, scale-up and commercial application of difficult processes. Emphasis is placed on practical applications of rheological concepts developed both academically and empirically. The cause-effect relationship between the process chemistry and possible physical implications on the metallurgical plant operability is presented in a simple, direct form. Examples include recent metallurgical results in several areas including base, precious and light metals. Technical process risk factors and their mitigation are included in the discussion.

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2:50 PMImplementation of New Technology at Barrick Gold: Peter Kondos1; Peter Lind1; Nathan Stubina1; 1Barrick Gold Corporation Barrick Gold is in the process of building several new mines and implementing new processes at existing mines for which metallurgical technology is of key importance. The roles of the company’s Strategic Technology Solutions team and the Barrick Technology Centre are discussed within the context of their responsibilities within Barrick’s Operations Support group. The paper will present an overview of the development of the technology centre from the former Placer Dome Research Centre to its current form supporting strategic technology, capital projects, and operating sites. Novel approaches to research and development will be presented as well as an overview of some of the technologies developed from bench-scale to pilot-scale, and beyond.

3:15 PMDevelopment of Low Technical Risk Commercial Designs Using Fluidized Bed Pilot and Demonstration Plants: Stanley Bunk1; Eric Eccleston1; Jennifer Amsden1; 1Technip Fluidized bed technology has been widely applied to mineral and metallurgical processes. Over the years, modeling of fluidization technology has progressed to a level at which basic design parameters can usually be defined based on empirical correlations. In addition, scale-up considerations have become better understood, and significant advances have been made in the area of computer simulation. Despite these advances, fluidization is a complex phenomenon, and modeling tools remain limited in their ability to simultaneously model both fluidization and chemical process parameters. As a result, almost all mineral and metallurgical applications of fluidized bed technology require pilot testing prior commercial scale design. This paper outlines pilot plant testing requirements and process development considerations for development of low technical risk commercial designs.

3:55 PM InvitedSuccessful Project Implementation: Kenneth Thomas1; 1Kinross Gold Corporation Since approximately 2003 we have witnessed the unprecedented escalation in commodity prices. Couple with economic chaos following the 2008 downturn this has caused difficulties in controlling schedule, capital costs and operating costs for mining projects. Once again escalation has returned to commodity prices fueled by growth in the BRIC countries especially China and Brazil. This is further exasperated by the missing generation of skilled technical personnel not graduating from universities in the 1980’s and 1990’s owing to depressed commodity prices. This paper examines the six tenets for successful project implementation.

4:20 PMDeveloping Vale’s Nickel Hydroxide Processing Technology: Gregg Gavin1; Ahmed Vahed1; 1Vale Base Metals Technology Development The Vale pilot plants in Port Colborne were constructed by Inco in the 1960s and used extensively to test major process changes in existing operations as well as developing new technologies. The Copper Cliff Nickel Refinery using the pressure carbonyl process was one of the outcomes. Developing new technologies for the lateritic nickel deposits Inco owned in various countries was a multi-year program of research in the 1970’s. This was also major role of the Port Colborne pilot plants. Initial technical feasibility and miniplant test programs for these projects were generally performed at one of Inco’s R&D centers in Copper Cliff or later in Mississauga and, if warranted, followed with pilot scale studies at the Port Colborne pilot plant. These studies were essential to provide the company with robust designs for its commercial plants worldwide, as well as redesigning or modernizing its operating plants. During the 1980’s, the

major development efforts were to refine the processes to be adopted during the billion dollar refit of the Copper Cliff Smelter in the early 1990’s. After this success, and amid the industry recession of the 1990’s, the 3 pilot plants (called Research Stations) were mothballed. In 1998, as Vale (Vale Inco at the time) was developing the flowsheets for a new generation of laterite processing plants, it was decided to restart the Pyrometallurgical Research Station. This paper describes the role of the newly refurbished pilot plant in the successful piloting of a process to turn nickel hydroxide precipitate into a marketable nickel product. The value of pilot scale processing was once again clearly demonstrated.

4:45 PMDesign and Implementation of Modified Mo Addition to EAF at Uddeholm Ab, Sweden: Seshadri Seetharaman1; Andrei Chychko2; Lidong Teng1; Mselly Nzotta3; 1Royal Institute of Technology; 2Era Steel Kloster; 3Uddeholms AB During Mo additions, there were significant losses to the dust (ca 7 %) and to the slag phase (ca 2 %), which had serious economic and environmental impacts. The present work was aimed at designing a suitable Mo precursor, as the Mo source and a process sequence. The criteria were a) low cost of raw materials, b) minimize vapour losses and c) easy dissolution of the precursor in molten steel. After thermodynamic considerations, three precursor materials were chosen, viz. CaMoO4, MgMoO4 and Fe2MoO4. Synthetic mixtures of the component oxides in each case as well as pure MoO3 were investigated by TGA and high temperature XRD in order to find out the temperature range in which the compounds were formed. Experiments were also conducted separately where the evolved gases were analyzed. All the three precursors were formed easily and the loss of MoO3 to the vapour phase was found to be extremely low. Addition of the oxide mixtures to steel melts were conducted in three different scales, viz. 16 g, 500 g and 3 tons (induction furnace). Initial experiments showed that MgMoO4 was not suitable since the Mo yield in the steel melt was not very high. Fe2MoO4 was found to perform best, the Mo yield reaching 98 %. Further trials were conducted in the 100 ton Electric Arc Furnace at Uddeholm AB in Hagfors. Mixtures of mill scale, MoO3 and carbon in suitable proportions were added in a pre-determined addition sequence. It was found that, in the actual practice, the Mo yield reached 99 %, equaling in performance the addition of ferromolybdenum. The process has been patented and is being currently implemented at Uddeholm AB, Hagfors, Sweden.

5:10 PMDRI-based Continuous Steelmaking: From Theory to Practice: Mansoor Barati1; 1University of Toronto A collaborative research between University of Toronto and Hatch was conducted to understand and optimize the process conditions pertaining to a novel steelmaking technology. In this technology, known as CRISP, direct reduced iron is continuously melted and refined in a stationary electric arc furnace. The major challenge against continuous operation of the electric furnace was identified to be minimizing the corrosion of the refractory in order to achieve uninterrupted operation for a minimum of one year. Theoretical analysis and bench scale experiments together with two pilot runs resulted in defining an operating window for slag chemistry that would minimize chemical attack to the refractory while satisfying the oxidizing conditions required for sufficient decarburization. An analysis of the process in terms of energy consumption and emission of greenhouse gases revealed that it is superior to the current batch DRI–based steelmaking technologies.

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WASTE RECYCLING IN MINERAL AND METALLURGICAL INDUSTRIES: Advances from Japan. Precious Metals

Tuesday PM Room: VerdunOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: T.T. Chen, CANMET; Takashi Nakamura, Tohokum University

1:35 PMIntroduction to Japan Projects: Atsushi Shibayama1; Akira HOSOI1; Ken-ichi HIRUTA1; Yasushi TAKASAKI1; William TONGAMP1; Takahiro KATO1; Katsuyasu SUGAWARA1; 1Akita University Printed circuit boards of discarded personal computers, televisions, mobile phones and so on contain a significant amount of valuable metals. For the recycle of valuable metals contained in the printed circuit board wastes (PCBW), the effect of temperature on chlorination–volatilization of metals under chlorine gas flow was studied. The experimental sample used was powder of two types: crushed PCBW (Sample 1) made from PC and industrial machines, and crushed–combusted PCBW (Sample 2) made from Sample 1. The principal element in Sample 1 and Sample 2 was copper, about 13 wt% and 20 wt% respectively. Sample 1 was composed of pure metals such as copper, tin and lead. In comparison, Sample 2 consisted of oxide metals such as copper oxide, tin dioxide and silicon dioxide. The two samples were heated at predefined temperatures (ranging from 300 °C to 900 °C) in chlorine gas. The chlorine gas flow into the furnace was set at a rate of 100 mL/min. As a result, copper in Sample 1 began to volatilize at 600 °C and completely vaporized at 700 °C. While in Sample 2, copper started to volatilize at 600 °C and reached 100% vaporization at 800 °C. For Sample 1, zinc finished volatilizing at 500 °C, while for Sample 2, zinc volatilization reached only about 80% (maximum). Also, lead, nickel and titanium showed similar results. Consequently the volatilization rate of Sample 1 is higher than Sample 2 and the temperature dependency was verified for copper, lead, zinc, nickel, antimony, titanium and chromium. In fact, the volatilization rate of these metals increased with the temperature. This result reflects the difference between pure metal and metal oxide, as Sample 2 was combusted before the chlorination–volatilization test. Moreover, the chlorination reaction may be accelerated by a reductive atmosphere because Sample 1 contains carbon. In this study, the volatilization behavior of some valuable metals in PCBW by chlorine gas was observed. Further improvement in the rate of volatilization can be achieved by optimizing the experimental conditions.

2:00 PMRecent Trend of Rare Metals Recycling in Japan: Shuji Owada1; 1Waseda University Scrap electric and electronic appliance, so called “E-waste”, is not a present target to be collected and recycled in Japanese regulation. The materials, however, contain considerable amount of base, precious metals, and in especial rare metals which facilitate multifunction and downsizing of the appliances, then, such kinds of metals should be recovered from the “E-wastes”, for keeping stable supply and establishing “sound material-cycle society”. Ministry of Economy, Trade and Industry (METI), and Ministry of the Environment (MTE) have recently started a national project for creating collection systems in several areas and for developing technologies to recover them. The paper describes the present situation of Japan’s rare metals recycling system, involving various collection procedure and technologies for pretreatment, concentration, and extraction. The paper also describes detailed research work to clarify how various kinds of rare metals are distributed in the “E-waste” and how they should be pulverized and concentrated to produce the concentrates from which rare metals can be extracted and/or stocked for future treatment. In the research, several pulverization methods were tried and compared to separate installed

electronic parts from the printed wiring board and the combination of several physical concentration methods was applied to achieve “parts separation” and “powder separation” for the concentration of rare metals. Pulverization and concentration mechanism were also clarified for each rare and other metal element.

2:25 PMLead Recovery from Waste CRT Glass by Hydrofluoric Acid and Electrochemical Treatments: Etsuro Shibata1; Mio Itoh1; Takashi Nakamura1; 1IMRAM, Tohoku University Both landfill and recycling of used cathode ray tubes (CRT) have been done in the world and which way was selected in each country depends on environmental policy of each country. Almost 100% of material recycling was achieved in Japan past decade. However, recycling of waste CRT glass has recently faced a strong difficulty to continue because a demand of CRT TV has drastically decreased due to wide spreading liquid crystal display (LCD) TV in the world. It becomes necessary to treat and recycle the waste CRT glass domestically due to the shutdown of the foreign CRT manufacturers. A part of CRT glass is recycled as a raw material in the lead blast furnace. However, it is difficult to treat all of the waste CRT glass in the lead blast furnace because the CRT glass contains a high content of silica. We need some additional treatments of waste CRT glass for lead smelting materials. In this study, we treated the waste CRT glass using hydrofluoric acid to dissolve the contained silica, and then the dissolved lead was recovered by precipitation methods. Besides, the lead metal was recovered by electrodeposition from the prepared hydrofluorosilicic acid solution.

2:50 PMA Computer Simulation of an Agitation Mill Abrasion Process for Waste Printed Circuit Boards: Chiharu Tokoro1; Yuki Tsunazawa1; Kenichiro Torigoe1; Shuji Owada1; 1Waseda university Recycling of printed circuit boards (PCBs) is an important subject not only from the treatment of waste but also from the recovery of valuable materials including rare metals. However, effective physical separation process including communition has remained to be established. We already confirmed that a special and selective grinding such as parts abrasion from the board using agitation mill was effective for the recycling of a part of rare metals. It is important to investigate the brief mechanism of parts abrasion process from PCBs in agitation mill. The objective of this study is revealing the mechanism of parts abrasion process from PCBs using discrete element method (DEM) simulation. In order to calculate parts abrasion process directly in DEM, a PCB was constructed by many fine particles bonded each other. This connection between them was broken if the bonding force calculated from DEM became over a threshold level. An anchoring model was developed as a new bonding model to avoid the displacement of bonding point between particles. Simulation results were compared with experimental communition data using agitation mill with simulant PCBs on which nine capacitors were solder-mounted. In experimental communition test, both of parts abrasion rate and boards breakage rate were increased as rotation speed increased. On the other hand, as the amount of input increased, parts abrasion rate was increased while boards breakage rate was slightly decreased. Simulation results obtained from DEM with the anchoring model corresponded to these experimental trends successfully.

3:15 PMDistributions of Minor Metals in E-Waste: Tetsuya Yumoto1; Toshikazu Shiratori2; 1Tohoku University (Present at Dowa Eco-System Co.,Ltd.); 2Tohoku University E-Waste that originates in EOL(End of Life) is abandoned after a certain period of use. It is important that we obtain information on the elements used for these E-Waste from the viewpoint of recycling. Especially, the usage conditions of various minor metals (rare earth etc.) that have been used for the recent equipments and some elements that have been limited to use due to harmfulness are constantly changing. However, these information are not sufficient. Therefore, we analyzed several parts in WEEE (Waste Electrical and Electronic Equipment) of EOL collected directly from the citizens. The

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distribution of the minor metals in WEEE were clarified by the positional information analysis using the X-Ray Analytical Microscope and chemical analysis. Moreover, in some equipments, the annual change of the content of the elements was investigated by analyzing equipments at different years of manufacture. We would like to apply the information to the separation techniques that the advanced recycling will be requested in the future.

3:55 PMSelective Recovery of Gold from E-wastes by Using Cellulosic Wastes: Katsutoshi Inoue1; Bimala Pangeni1; Minoru Abe1; Hidetaka Kawakita1; Keisuke Ohto1; Shafiq Alam2; 1Saga University; 2Memorial University Selective and effective recovery of gold was investigated by using adsorption gel prepared from pure cellulose by crosslinking with concentrated sulfuric acid. It was found that only gold was quantitatively adsorbed with extraordinary high loading capacity from varying concentration of hydrochloric acid separated from other metals including other precious metals and base metals. The formation of fine powders of metallic gold was visually observed, which is attributable to the selective reduction of gold(III) ion to metallic gold due to its high oxidation-reduction potential. This technology was extended to prepare similar adsorption gels from cellulosic wastes like spent paper and spent cotton. These adsorption gels were tested for the effective recovery of gold from leach liquor of hydrochloric acid of various e-wastes like circuit board of spent mobile phones.

4:20 PMRecovery of Precious Metals by Means of Adsorption Using Persimmon Tannin Gels: Manju Gurung1; Katsutoshi Inoue1; Keisuke Ohto1; Hidetaka Kawakita1; Shafiq Alam2; 1Saga University; 2Memorial University Two kinds of adsorbents were prepared from persimmon tannin extract; one was prepared by treating with concentrated sulfuric acid for crosslinking between polymer matrices of tannin and/or polysaccharides existing in the extract together with tannin while another was prepared by immobilizing functional groups of quaternary amine. These are termed as CPT and QAPT, respectively, while the original persimmon tannin extract as PT powder. The adsorption tests were carried out from varying concentration of hydrochloric acid, from which it was found that only gold(III) was selectively adsorbed on PT powder and CPE gel while not only gold(III) but also palladium(II) and platinum(IV) were selectively adsorbed on QAPT gel. In these cases, base metals such as copper(II) and iron(III) were not practically adsorbed. Adsorption isotherm tests suggested that maximum adsorption capacities of QAPT, CPT and PT powder were 4.16, 7.7 and 5.8 mol/kg, respectively, for gold(III) while those of QAPT for palladium(II) and platinum(IV) were 0.84 and 0.52 mol/kg, respectively. The formation metallic gold by the reduction of gold(III) ion by polyphenols was considered to be responsible for the high selectivity and adsorption capacity for gold(III).

4:45 PMPrecious Metals Leaching from Electronic Wastes: Fereshteh Rashchi1; Nasrollah Naseri Joda1; 1University of Tehran Recycling of electronic wastes is an important subject not only from environmental treatment point of view but also from the recovery of valuable materials. In this research, PC board scraps were used for leaching of Cu, Ag, Au and Pd. Due to the high cost of crushing and grinding processes and to avoid secondary pollution from odors and dusts created during the comminution process, board scraps were cut in pieces of 5�5 cm2. To determine the most effective leachant, aqua regia, nitric acid, hydrochloric acid, ammonium persulfate and potassium persulfate were tested. The operating variables, the leachant concentration (1-5 M), temperature (30-70 °C), leaching time (0.5-2.5 hr) and liquid to solid ratio (5-25) were studied and optimized using Response Surface Method.

5:10 PMVolatilization Behavior of Valuable Metals in Electronic Substrate Waste by Chlorination-Volatilization: Atsushi Shibayama1; Akira Hosoi1; Kenichi Hiruta1; Yasushi Takasaki1; Takahiro Kato1; Katsuyasu Sugawara1; 1Akita University Printed circuit boards of discarded personal computers, televisions, mobile phones, etc. contain a lot of valuable metals. For the recycle of valuable metals contained in the printed circuit board wastes (PCBW), the effect of temperature on Chlorination-Volatilization to investigate metals under chlorine gas flow was performed. The experimental sample used was powder of two types: crushed PCBW (Sample1) made from PC and industrial machines and crushed-roasted PCBW (Sample2) made from Sample1. The principal element in Sample1 and Sample2 was copper, about 13wt% and 20wt%, respectively. Sample1 was composed of pure metals such as copper, tin and lead. In comparison, Sample2 consisted of oxide metals such as copper oxide, tin dioxide and silicon dioxide. The two samples were heated at predefined temperatures (ranging from 300°C to 900°C) in chlorine gas. Chlorine gas flow into furnace was set at a rate of 100mL/min. As a result, copper in Sample1 began to volatilize at 600°C and completely emitted at 700°C by the Chlorination-Volatilization process. While in Sample2, copper started to volatilize at 600°C and reached 100% emission at 800°C. For Sample1, zinc finished volatilizing at 500°C, while for Sample2, zinc volatilization reached only about 80% (maximum). Also, lead, nickel and titanium showed similar results. Consequently, it transpires that volatilization rate of Sample2 is higher than Sample1 and the temperature dependence was verified for copper, lead, zinc, nickel, antimony, titanium and chromium. The volatilization rate of these metals increased with the temperature. This result reflects the difference between pure metal and metal oxide, as Sample2 was roasted before Chlorination -Volatilization test. Moreover, chlorination reaction may be accelerated by reductive atmosphere because Sample1 contains carbon component. Here, the volatilization behavior of some valuable metals in PCBW by chlorine gas was observed. Further improvement in rate of volatilization can be achieved by optimizing experimental conditions.

WORLD GOLD: Comminution/Concentration

Tuesday PM Room: Mont RoyalOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: S. Acar, Newmont Gold

2:00 PMBulk Flotation Characteristics of a Sulphidic Gold Ore from the Barry District of Quebec: S. Kelebek1; E. Yalcin1; 1Queen’s University This paper reports bulk flotation characteristics of a pyritic gold ore sample from the Barry District, Quebec using isopropyl and amyl xanthates. The ore sample was highly floatable with particles showing tendencies for self-aggregation that was most apparent in the first stage of flotation. A possible reason for this is discussed. The gold concentrate grade-recovery performance with respect to the particle size is presented for the rougher-scavengers as well as for the cleaners. The effects of copper sulphate as an activator, fuel oil and NaSH as a sulphidising agent are discussed along with the recovery by size behaviour.

2:25 PMThe Current Status of the Chemistry of Gold Flotation in Industry: Ronel Kappes1; Robert Dunne1; Carole Fortin1; 1Newmont Mining Corporation The subject of gold flotation has been reviewed extensively in a number of publications. The focus in most of these reviews has been on the theories of gold flotation as well as the physical and chemical effects that may impact the efficacy of the gold flotation process. It is evident that the current status of gold flotation chemistry as it is being applied in industry

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has not been addressed widely. It is the intent of this paper to review current gold flotation practice and how these applications tie in with the current understanding of the chemistry of gold flotation.

2:50 PMHydrocyclone Classification Modeling for Gold Ore Grinding Circuit Simulation: Steve Bellec1; 1Universite Laval Industrially, cyanidation is widely used to extract gold from raw ores. To enhance the kinetics of the dissolution reaction that occurs at gold grain surface, gold accessibility is facilitated by ore crushing and grinding under a critical particle size. Grinding is achieved in closed circuits where hydrocyclones are used to recycle coarse particles back to the mills. The separation performed by hydrocyclones is influenced by particle density and size. As gold density is larger than that of the accompanying gangue, the gravimetric effect in hydrocyclone classification is important and for a given size, free gold particles have larger probability to be recovered at the hydrocyclone underflow than mixed or gangue particles. This paper proposes a classification model to predict the split coefficient as a function of the particle size and gold content. The model is calibrated and validated using data obtained from the sampling of an industrial grinding circuit equipped with two parallel grinding mills. Model calibration requires a complete simulation of the circuit and involves parameters related to the gold grain distribution in the raw ore as well as a liberation model. Since cyanide is added into the studied grinding circuit, it is necessary to make assumptions about gold dissolution in the mills. The simulation results confirm the preferential recirculation of free gold. The model is used to propose a hydrocyclone tuning that reduces gold recirculation in the grinding circuit with minimal impact on gold surface accessibility to the cyanidation reaction.

3:15 PMMineral Separation Techniques in Gold Recovery from Refractory Ores: Qi Liu1; 1University of Alberta Gold recovery from refractory ores can be very complicated depending on the causes of the refractoriness. Typically, a fine grind and/or the oxidation of the gold-bearing sulfide minerals are required to liberate gold from the host rock matrix. Mineral separation techniques, particularly surface-wettability based (flotation) separation and magnetic separation, can be used to pre-concentrate the gold and sulfide minerals, or to remove mineral species that are harmful either to the oxidation of the gold-bearing sulfides or to the cyanidation following the oxidation. In this paper, several possible processes are described, including oil-agglomeration-flotation ecovery of fine gold, reverse flotation of carbonate minerals prior to pressure or bio oxidation, reverse flotation of elemental sulfur after pressure or bio oxidation but prior to cyanide leaching, and flotation recovery of fine gold-bearing activated carbon, as well as magnetic concentration of gold-bearing iron oxides. The integration of these techniques with gold hydrometallurgical processes may make the economic recovery of gold from an otherwise uneconomic refractory ore possible.

3:55 PMSelective Separations of Gold and Contaminants from Various Gold and Silver Process Streams: Neil Izatt1; Steven Izatt1; Ronald Bruening1; 1IBC Advanced Technologies, Inc. IBC Advanced Technologies- Molecular Recognition Technology (MRT) SuperLig® products selectively and rapidly bind with target metal ions to remove them from solution. The MRT process can produce a high purity separation product of maximum added value at low cost. This paper discusses applications for MRT in the gold industry, including recovery of gold and silver as well as contaminants from various process and recycle streams.

WORLD GOLD: Geology II

Tuesday PM Room: Fontaine DOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: G. Kirkham, Consultant

2:00 PMDetour Lake – Discovery of a World-Class Gold Deposit in Ontario: Gerald Panneton; Pat Donovan; Roger Aubertin; 1Detour Gold The Detour Lake gold project is located approximately 300 km northeast of Timmins within the northwestern portion of the Abitibi greenstone belt, Superior Province. The site was subject to underground and limited open pit mining activity from 1983 to 1999, during which time it produced 1.8 million ounces of gold. From the acquisition of the property to now, Detour Gold has completed over 500,000 m of diamond drilling and has defined an open pitable high tonnage gold deposit. A shear hosted gold deposit typical of Archean deposits, it is centred on a major structure (the Sunday Lake Deformation Zone - SLDZ) at the contact of the Deloro Group volcanics, mainly comprised of massive and pillowed mafic volcanics and minor ultramafics, and the younger Porcupine sedimentary sequence. This major east-west structure can be traced for more than 30 km across the property. The bulk of the gold mineralization occurs in the hanging wall of the SLDZ. Gold mineralization within the Detour Lake deposit is present along a 200 m wide (locally up to 350 m), east-west corridor forming a stockwork of auriferous, steeply dipping quartz veins that splay from a flexure coinciding with the northern limb of a west plunging antiform. The mineralized corridor has been tested along a strike length of over 3 km and remains open to the west. Nearly all (98%) of the gold mineralization at Detour Lake occurs in a free state. The Company completed a positive feasibility study in June 2010. As of January 2011, the estimated open pit reserves are 14.9 million ounces. Detour Gold is currently constructing the mine and plans to be in production in the first quarter of 2013. The open pit mine will be among Canada’s largest gold mining operations with a planned average production rate of over 650,000 ounces annually.

2:25 PMGold in the New Geological Framework of the Hope Bay Belt, Kitikmeot, Nunavut, Canada: Marc Bardoux1; M. Stubley1; P. Thompson1; 1Newmont Mining Corporation Four N-S trending tectonostratigraphic domains are defined across the entire Hope Bay Belt with the two oldest domains lying on the edge of the belt and younger ones (dominantly sedimentary) in the middle. Ca. 2.69Ga old mafic metavolcanic rocks and nearby sediments affected by high strain zones and tight fold structures are the main host of the 3 open ended gold deposits defined to date in the eastern half of the belt. Tens more significant gold (copper) occurrences spread throughout the 1500km² of greenstone including some bounding granitoids. Gold relates to at least two stages of Archean hydrothermalism and mainly vertical tectonism that may in part be highlighted by discrete metamorphic conditions. TiO2 rich mantle derived basalts are good (but not exclusive) hosts or proxies to gold mineralization for 2 deposits. Granitoids surrounding all supracrustals are probably melts derived from garnet-amphibolite sources. Convoluted contacts between granitoids and supracrustals translate to significant structural complexities within the supracrustals coinciding also with 2 of the 3 deposits. Granitoids likely settled at mid-crustal levels developing a thermal blanketing effect into the hosting supracrustals while inducing partitioned plane strain (mainly L tectonites) to their own margins as well as to nearby supracrustals. U-Pb dating suggests that cooling of the oldest bounding granitoids occurred soon after the last extrusive event recorded in supracrustals. Ar-Ar dating indicates Paleoproterozoic resets likely coincide with reactivation of Archean structures in the southern part of the Hope Bay Belt. Paleoproterozoic gold has yet to be demonstrated.

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2:50 PMSyngenetic Gold: Lode Vein Geology and Exploration Implications: Ulrich Kretschmar1; 1Golden Scarab Corporation Mapping, core logging, WR analyses and re-interpretation of textures shows lode veins (LVs) occur in a “gold cycle”. In turbidite terminology, LVs occur in “E” ( pelagic-pelitic) rocks or at contacts. E lithologies are “shear zone”, lamprophyre, mafic dike, flow or “enclave”. They are small scale correlative conformities described by Thurston et.al. 2008 (Ec Geol 103 p.1097). Basal or “A” division volcaniclastics annealed by metamorphism resemble igneous texture. “Intrusion” gold is hosted by gabbro, diorite, granite, syenite and TTG. “Gold-cycles” in these rocks indicate extensive early Archean pyroclastic volcanism. The 2830 my Maskwa, MN “batholith”, a quartz (Q)-feldspar (F)-hornblende (H) crystal tuff (CT) hosts high grade LVs over 8,000 m by 500 m. The 2730 my Chester Twp, ON “trondhjemite-diorite”, is a heterolithic volcanic breccia and felsic CT host to the 4M oz Cote Lake deposit of Trelawney Mining. The Baxter shaft is on the S limb of an overturned syncline. In Beardmore ON, Hercules veins (Prodigy Gold, >130,000 oz) are hosted by > 10 km long SW facing Elmhirst mafic CT and volcanic breccia. Eight mines in the 2700 my PQ Bourlamaque batholith, a metamorphosed QFH CT, correlate across a syncline with an overturned S limb. The geopetal nature and asymmetric alteration of LVs indicates sea-floor genesis. Bedding parallel LVs differ from fragmentation-breccia (feeder) veins. Often Q was deposited as a gel. Grade-thickness plots reflect vent geometry (fracture, point source or diffuse seep) and bottom topography. LVs are commonly 500-2,000 m long and disc-shaped or lobate. Average 2-450 m ore “shoot” spacing represents sea-floor fractures. LV grades reflect geothermal fluid composition, P-T and sedimentation rates. Structural upgrading is not required. Syngenesis clarifies and simplifies genetic models. Exploration becomes more cost-effective. Basin analysis, WR geochemistry, ore lens geometry and vent spacing can be used. Gold cycle facing survives metamorphism.

3:15 PMMeeting the Challenges of Gold Exploration through Earth Probe High Resolution Borehole and Surface IP: Rob Gordon1; 1Caracle Creek Geophysical exploration for gold is known to be challenging. Recently, some of the limitations of traditional IP have been addressed by drawing upon smaller-scale technologies developed for engineering geotechnical and hydrogeologic applications. The University of Toronto, through CAMIRO funding, progressed initial studies to adapt a geotechnical resistivity system developed by Geoserve in Germany for mining applications (Qian et al, 2007). Caracle Creek has further developed Geoserve’s resistivity system, with the assistance of IRAP funding, to incorporate induced polarization measurements for mining applications. The resultant EarthProbe DCIP system is successfully enabling geophysicists to adjust their scale of surveying to the scale of geologic features applicable to gold exploration. EarthProbe’s narrow electrode spacing and ability to operate in multiple surface and borehole configurations facilitates both improved target delineation and characterization of host rock and mineralization signatures. Integration of high-resolution surface and borehole IP survey techniques is helping to address many of the challenges faced by geologists when exploring gold environments. This is attributed to the system’s ability to: rapidly collect integrated surface, borehole, borehole-to-borehole and surface-to-borehole data; image smaller features and disturbances often related to narrow vein type systems of disparate mineralization due to the use of tight electrode spacings; provide a range of information to the geologist regarding near surface and mid-depth features;identify in-hole and off-hole features and between hole connectivity of electrical/ chargeable features, and characterize bulk resistivity/chargeability of key lithologies and alteration/mineralized zones. Three recent case studies will be showcased.

3:55 PMUse of Multivariate Geochemical Domains as a Validation Tool in the Classification of Predicted Resource Metal Extraction Recoveries. Fruta del Norte Gold Deposit, Ecuador, Case Study: Cristian Dragusanu1; John Sims2; James Connolly1; 1SGS Minerals Services; 2Kinross Gold Corporation Geometallurgical methods of ore classification are more and more part of the current practice believed to enhance the economic predictability of a deposit. In this sense, the basic geological observation of drill cores can benefit from a combined approach where quantitative measurements from densely probed core can validate relationships between metal recovery and metallogenetic assumptions. Such complementary techniques can solve cases of apparent decoupling between host rock genetic controls and mineral processing which may be seen in complex environments. Based on a statistical analysis of the categorical and numerical data from the established geological model, a geochemical classification of mineralization has been shown to be objective in nature and correlated to the envisioned metal extraction process. On the assumption that the major chemical variation is controlled by the different mineral assemblages, a relationship can be found and turned into a model of mineralogical variation as a function of major chemistry. This work shows the potential of multivariate classifications based on the chemistry of the sampled core intervals to discriminate within a combined response from different types of alteration and metal abundances. Distinct domains of chemical response determined by clustering analysis were used to validate a geologically driven analysis of the gold occurrence. The groups established are spatially distinct, suggesting their intimate link to the geological process responsible for their genesis. The probabilistic occurrence of each group in the deposit was analyzed through sequential indicator simulation. Furthermore, a general spatial model was generated by grouping the nodes of the present block model using the same clustering technique on the linear estimates of the chemical elements that were used for the classification of the core intervals. This model proved robust in its interpretation of the geological observation and provided clarity in geologic modeling both from a validation and quantification viewpoint.

4:20 PMGold Exploration in Metamorphic Terrains Using Fluid Inclusion Compositions in Quartz: Signification of Their Volatile Content: Damien Gaboury1; 1Université du Québec à Chicoutimi Most hydrothermal gold deposits contain quartz with fluid inclusions that recorded composition and temperature. Quartz has strong chemical and mechanical resistances to weathering and mechanical abrasion. Hence, quartz fragments occurring at weathered surface or in till cover have the potential to be used for gold exploration; as far as we know what is the volatile contain signification for gold mineralization. In this perspective, fluid inclusions were analyzed in pure quartz by mass spectrometry following the method of Gaboury et al. 2008 (Econ Geol) from gold deposits hosted in the Archean Abitibi and Paleoproterozoic Birimian belts. This approach provides the relative abundance of volatiles from families of fluid inclusions decrepitating at specific temperatures (Td). Fluids in gold deposits are aqueous-dominated with CO2 and H2S in accordance with their fundamental role as gold-ligands (H2S) and for pH-buffering (CO2) of the gold-bisulfide solubility. However, there is no correlation between CO2 and H2S contents of fluid inclusions and gold content of the samples. This implies that trapped fluids represent a marginal portion of the fluid history recorded by the veins. However, in barren quartz veins away from known mineralization CO2 or H2S are absent. Wide H2O Td spectrum from 200-450°C and CO2-H2O Td offset are common, indicating phase separation. The content of other volatiles seems to be more dependant of the geological setting. Helium content may suggest proximity of a crustal-rooted fault, a critical parameter for gold mineralization. Methane and especially C2H6 appear to be indicative of fluid buffering with organic-rich material such as graphitic-shale. These rocks may provide an important primary gold reservoir from sedimentary metal-rich pyrite. Nitrogen-

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bearing fluid may be related to a magmatic component as proposed but our data are inconclusive. For gold exploration, quartz containing CO2- H2S-bearing fluid inclusions and having H2O-CO2- Td offset within 200-450°C has strong vectoring potential.

WORLD GOLD: Management and Mineral Economics

Tuesday PM Room: Fontaine EOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Monica Ospina, Market Access

2:00 PMOutlook of Gold: M. M. Murenbeeld1; 1Consultant Not available

2:25 PMGold Rocks! – Can Miners Roll?: Paul Burton1; 1Thomson Reuters GFMS Not available

2:50 PMM&A Trends in the Gold Sector: John Nyholt1; 1PwC LLP The session will include a brief summary of deal metrics in the gold sector including: global deal volumes and value; and deals by size, geography and stage. An overview of key M&A issues will also be discussed. Key issues include: Where are the deal opportunities today? We will comment on increased activity earlier in the gold mine life cycle and in frontier political regions. Unique considerations for the latter types of deals, including political risk assessments and long-term hedging strategies, will also be discussed. How far will stakeholders go? Increased intervention from governments, NGOs and other stakeholders is making executing and closing deals in the gold sector more challenging. We will discuss what kind of intervention we are seeing in the deal market and what strategies entities can employ to mitigate deal disruption. What’s behind spinoff activity in the market today? Recent announcements by major gold producers to spin off gold units beg the question: “is the smart money getting out at the top of the market?” The strategic rationale for spin-offs and our perspective on expected future spin off trends will be discussed. How much is too much? In an absolute sense, deal valuations in the gold sector have never been higher. We will present some alternate approaches to assessing how “fair” deal values are today, including an analysis of price paid per reserve vs market price. What is China’s strategy? China continues to be acquisitive in the mining sector. We will set out what Beijing’s strategy is in the gold sector and, in light of China’s new five year plan, what to expect for 2012. M&A in the gold sector is quite dynamic, so should market conditions change leading up to the conference, the focus of this presentation may also be altered to reflect those changes.

3:15 PMOpportunities for Managing Community Relations through the Supply Chain: Monica Ospina1; 1o trade and market access Trade across the supply chain can boost demand for products, services and labour, not only in international markets but also at the local level, where mining companies have a direct input in local economies. Apart from good governance and socially and environmentally responsible practices, local supply and employability are recognized by the International Financial Corporation, Export Development Canada and financial institutions when evaluating companies applying for financing. In this session, participants will learn how to analyze trade within the supply chain and harness its potential for building local economies and managining community relations. Emphasis will be given to the role of capacity building in presenting a long- term solution to reducing poverty, and building self-sustaining and sustainable economies at the local level, thus making of the mining industry an agent for sustainable development.

3:55 PMBanro Corporation: Investing in Long-Term Community Development: Martin Jones1; 1Banro Foundation Banro is a Canadian-based gold exploration and development company with projects in the DR Congo. The Company is constructing its first mine at its Twangiza project, which is scheduled to begin production in late 2011. Banro has made a commitment to the people of its region to work with them to lift the quality of life in the years ahead. This commitment is expressed through the Banro Foundation, a registered charity which makes strategic investments in education, health and infrastructure development. Among the principles guiding the Banro Foundation is a focus on needs identified by local community leaders, with priority given to projects that benefit communities as a whole. Since 2008, the Foundation has, among other projects, completed the construction of four new schools, a women’s resource centre, a potable water delivery system serving 18,000 people, a new health care centre, the development of over 100 kilometres of roads and bridges and two shipments of medical equipment from Canada to several regional hospitals in the eastern DR Congo. 2011 is planned as the most active year ever for the Foundation, with four new schools, a regional marketplace, a health care centre and a major bridge under construction.

4:05 PM Concluding Comments

WORLD GOLD: None Cyanide Lixiviants

Tuesday PM Room: Hampstead / Cote St. LucOctober 4, 2011 Location: Hilton Bonaventure Hotel

Session Chair: P. Breuer, CSIRO

2:00 PMRecovery of Gold and Associated Metals from Refractory Ores and Concentrates via a Chloride-Based Processing Route: Bryn Harris1; 1Neomet Technoligies Inc Cyanide has been used for the recovery of gold since the mid 1800s. However, a number of jurisdictions have already banned its use, and recent spills, such as that into the Danube, are increasing environmental pressures to finding an alternative for cyanide. It has long been known that gold also forms chloride complexes similar to those of cyanide, but its use has never achieved widespread acceptance. This paper describes a chloride-based flowsheet, wherein the key unit process is the recovery and recycle of chloride ion. Results of continuous miniplant runs on a low-grade refractory gold ore are presented, together with preliminary operating and capital costs. It is shown that the chloride-based flowsheet is competitively economically with the conventional cyanide-based flowsheets, and that it has a number of other advantages, particularly environmentally.

2:25 PMThe Nichromet Technology for Precious Metal Recovery: Jean-Marc Lalancette1; David Lemieux1; Bertrand Dubreuil1; Caroline Chouinard1; 1Nichromet Extraction Inc. Nichromet Extraction Inc. has developed a new technology for the extraction and recovery of base and precious metals calling upon the use of halogens. This approach has been evaluated on a great variety of polymetallic ores, concentrates or tailings with recoveries at 95-98 % for gold, at 90-95 % for silver and at 95-99 % for base metals (Cu, Zn). The approach calls for the use of elemental chlorine in the presence of a small amount of bromide as the active agents for precious metals collection. Prior to chloridation, the ores concentrate or tailings are freed of sulfur by controlled oxidation. This operation brings the sulfur content down to 0.2-1.5 % from values as high as 40 %. This operation generates sulfur dioxide that can be transformed into sulfuric acid needed further down in the process. Arsenic, if present, is partly volatilized as arsenious oxide, which is stripped from the gas stream and stabilized as scorodite. After the sulfur removal, the residual solid is

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washed with water to remove sulfated base metals produced during the controlled oxidation; then, with hydrochloric acid to complete the leaching of base metals. The removal of sulfur and base metals prior to chloridation reduces very substantially the halogen consumption during the precious metals extraction, allows the collection of said base metals and leaves a barren solid with no capacity for lixiviate generation after precious metals recovery. /2 The chlorination is performed in a brine slurry in a vat reactor, at low temperature and at near atmospheric pressure, said brine containing low concentration of sodium chloride and small amount of sodium bromide. Chlorine is injected in the stirred slurry and the duration of the reaction is adjusted to achieve near complete extraction of precious metals, generally after one hour to three hours.

2:50 PMAn Electrochemical Investigation into the Effect of Lead on the Dissolution of Gold in Ammonium Thiosulfate-Copper Media: Gabor Csicsovszki1; John G. Peacey1; 1Queen`s University It is well known that lead ion is an effective accelerator of gold lixiviation in cyanide solutions. However, the effect of lead on the dissolution of gold in conventional ammonium thiosulfate-copper solutions is not as well-defined, based on the limited literature on this topic. Therefore, the main target of this study was to clarify the role of lead on the dissolution of gold in the (NH4)2S2O3-Cu leaching system. For this purpose, chronopotentiometry, linear sweep voltammetry and chronoamperometry were utilized to study the dissolution of a rotating gold disk electrode under various conditions. Chronopotentiometry with flame atomic absorption (FAA) analysis was first applied to monitor the mixed potential of the leaching system with different concentrations of lead under open circuit potential conditions. It was found that the dissolution of gold was significantly increased with lead concentration up to 10 mg/l Pb in the system of 0.1 M (NH4)2S2O3 and 50 mg/l Cu. To further investigate the effect of lead, linear sweep voltammetry was used on solutions containing only 0.1 M (NH4)2S2O3 and lead in different concentrations. The voltammograms suggested that the anodic dissolution of gold was virtually independent of lead concentration in the range of 1-10 mg/l while at a higher level of 20 mg/l Pb gold oxidation was improved. Chronoamperometry coupled with FAA assay was utilized to investigate the effect of lead on the anodic lixiviation of gold at constant potentials in solutions containing copper as well. In solutions containing copper, additions of lead were found to significantly increase the anodic dissolution of gold, even at concentrations as low as 1 mg/l Pb. As a practical benefit of the effect of lead observed on gold dissolution, high consumption of thiosulfate caused by high copper.

3:15 PMKinetics of Gold in Leaching Alkaline Sulphide Solutions: Simon Joshi1; Edouard Asselin; 1University of British Columbia Electrochemical testing was used to study the leaching of pure gold (99.99%) in 1 M Na2S solution. Potentiodynamic testing showed the corrosion current density and corrosion potential were about 0.6 uA/cm2 and -788 mV vs. SCE, respectively. During potentiostatic testing at -0.487 mV vs. SCE, relatively high current densities (3 to 7 uA/cm2) were observed. After potentiostatic testing the gold content of the test solution was measured and found to be on the order of 0.02 ppm. The current efficiency for gold dissolution was low indicating that sulphide oxidation was the dominant reaction occurring on the gold electrode with very little leaching of gold occurring concurrently.

3:55 PMElectrochemical Studies of the Gold-Electrolyte Interface under Thiosulfate Based Leaching Conditions: Janet Baron1; Jeffrey Mirza1; Anna Frydrychewicz1; Jacek Lipkowski1; Yeonuk Choi2; 1University of Guelph; 2Barrick Gold Corporation Leaching of gold using thiosulfate as a lixiviant has been considered as an alternative to the current industrial process that involves the use of cyanide. Research has shown that the reaction rate of the gold leaching process in thiosulfate solution can be improved by addition of thiourea [1]. However, the mechanism by which thiourea improves the gold leaching

reaction is still unknown. The main objective of this work was to understand the mechanisms of action of different additives, such as thiourea, that enhance the leaching of gold in thiosulfate solution. The gold leaching reaction in alkaline thiosulfate solution, and the surface passivation seen in this lixiviant, were investigated using sweep voltammetry. The leaching currents in different electrolytes were determined using Tafel plot analysis based on the mixed potential theory. The electrochemical studies were complemented with a characterization of the gold-electrolyte interface using surface enhanced Raman spectroscopy. The obtained results show how thiourea changes the mixed potential of the leaching reaction by preventing formation of oxysulfur compounds, which passivate the gold surface and decrease the rate of leaching. Other molecules such as 3-mercaptopropionic acid and Lcysteine were also studied as possible additives to prevent formation of this passive layer in the thiosulfate leaching system.

4:20 PMOxidative Leaching of Pyrargyrite by Ozone: F Nava-Alonso1; Carolina Rodriguez-Rodriguez1; Alejandro Uribe-Salas1; 1CINVESTAV Saltillo Pyrargyrite (Ag3SbS3) is a silver species that is not soluble in cyanide solutions. It is very abundant in some Mexican deposits causing low silver recovery when using the cyanidation process. This work proposes the use of ozone as oxidizing agent to dissolve the silver contained in pyrargyrite. Natural pyrargyrite from Zacatecas, Mexico, was used to evaluate, by means of a factorial experimental design, the effect of acid and ozone concentration on the silver dissolution. The tests were performed with 1 g pyrargyrite (-25 µm) in 800 ml water at 25°C, 800 rpm mechanical stirring and 1.2 L/min gas addition. Two levels of sulfuric acid concentration and ozone in gas concentration were evaluated: 0.18 y 0.72 mol/L of acid and 0.054 y 0.077 gO3/L. The highest silver dissolution (50 %) was obtained when using the higher acid and ozone concentrations, suggesting that further increases in the ozone concentration could increase the silver recovery.

LIGHT METALS: Aluminium Transformation III

Wednesday AM Room: LachineOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Gilles Dufour, Alcoa; Donald Gallienne, Aluminerie Alouette

8:30 AMPromoting Aluminium Development in Canada: Vision of AAC: Jean Simard1; 1Association de l’aluminium du Canada We are in an era of optimal choices within societies that are under mounting pressure by consumers who are better educated, better informed, more demanding and who are mobilized around unprecendented issues. By using aluminum in areas that contribute to reducing greenhouse gases – in materials used for mass transit, institutional architecture and certain civil engineering projects – we provide our engineers, designers and architects with the opportunity of creating sustainable work defined only by their imagination and talent.

8:55 AMAluminum Ships: Myths and Facts: Thomas Lamb1; 1University of Michigan There are many horror stories about aluminum in the marine environment and many are not based on facts, so they are myths. Myths must be addressed before progress can be made. This paper attempts to dispel the myths and state the facts. A common perception is that aluminum ships cost significantly more than steel ships. This paper illustrates that even though the cost of the aluminum structure is over 50% more than the steel structure, an “equivalent” aluminum naval ship can be built within 7% of the acquisition price of a steel ship. This is possible because of the cascading benefits of the aluminum ship’s significantly lighter weight. Aluminum ships also have a life-cycle cost advantage over steel ships because of reduced maintenance and fuel cost savings.

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9:45 AMAluminum in Public Transportation: Russell Long1; 1Alcoa Globally, society is striving for transportation that is comfortable, clean and fuel efficient. Governments are requiring improved fuel economy, reduced emissions and in many cases encouraging the use of hybrid or electric powertrains to meet this desire. City buses with their urban usage cycle, many hours of daily use and their high loaded weight are logical vehicles for emissions reduction efforts. Aluminum has been used extensively to reduce the weight of two different types of buses, a conventional diesel powered bus and an electric bus. The curb weight of the diesel bus was reduced by 11.8% resulting in a 6% fuel economy improvement. The use of aluminum in an electric bus reduced the curb weight by 7% resulting in a longer range. The electric bus prototypes have been completed and are being tested in normal usage conditions.

10:25 AMAluminum in Transportation: Case Study of the Development of a Light Weighted Refuse Collection Unit: Yves Archambault1; Gilles Dufour1; Petrino Buzatu1; Louis Lefebvre1; Jean Fortin2; Clermont Fortin2; 1Alcoa Innovation; 2Véhicules Inpak Inc. / Inpak Vehicles Inc. In the domain of transportation, aluminum has proven its contribution to increase fuel efficiency by light weighting automobiles and many types of trucks. Still, some sectors are reluctant to the arrival of a material replacing steel, used for decades; the sector of refuse collection is among those. An ambitious project has been set forth to develop the next generation of a light weight side-loading refuse collection unit. The unit was entirely redesigned using aluminum and based on the future requirements of municipalities regarding residential refuse collection. The new compacting systems were designed for low friction and allowed for smaller size hydraulics. The aluminum alloys were selected for their performance in other comparable and well known applications in heavy transportation vehicles. The final outcome of this project is a refuse collection unit showing a weight reduction of almost 30% compared to the actual steel design. This gain translates into an increased load capacity, thus reducing the number of trip to the dump site. Two prototypes were built and are presently being tested in real conditions.

10:50 PMFrame Optimization of a Hybrid Spyder Roadster: Maxime Tacher1; Alain Desrochers1; Ahmed Maslouhi1; 1Université de Sherbrooke BRP (Bombardier Recreational Products) designs and commercializes recreational vehicles such as watercrafts, sport boats, snowmobiles, ATVs… The Spyder roadster is the last product in the Can-Am product family lineup. To remain at the forefront of innovation, a hybrid motorization version of the Spyder is being developed in order to reduce fuel consumption and emission of greenhouse gases. But, the addition of electric components (e-motor, lithium-ion battery…) raises the issue of added weight and volume. Hence, the objective of this project is to reduce the frame weight in an effort to limit the total weight of the vehicle. The main difficulties are to meet the packaging demand while maintaining the frame stiffness and supporting the hybrid components. Furthermore, the new frame must tolerate specific impact load cases and resist to defined fatigue test cycling. The last point is to control the global cost, including the cost of raw material and production. In fact, this new frame has to be efficient while remaining production friendly. To reach this goal, a methodology in four stages was developed. First, there is the choice of the material. To this end, performance criteria such as cost, density, strength and stiffness are being considered in a bid to respect design constraints. Then, the centers of gravity of the Spyder main components (motor, fan heater, gas tank…) are to be computed in a bid to improve their position so as to keep the global center of gravity of the vehicle as low as possible. The volumes and their characteristics are also considered with the added constraint that the vehicle cannot be made any wider or longer. From there a skeleton of the structure is proposed. Based on this skeleton, member shapes will be defined considering the choice of

material and the various load cases that have to be sustained. Finally, from a practical point of view, the Spyder chassis design technique will incorporate Finite Element Analysis (FEA) simulation, as well as experimental testing on servo hydraulic testing machines. Preliminary analysis led us to consider aluminum as weight requirements predominate over rigidity specifications. To adapt aluminum on the new chassis, innovative frame topology and geometry will be explored to limit cost and improve performance.

11:15 PMThe Use of Thin Wall Components and Shell Design to Reduce the Weight and Improve the Performance of An Aluminum Semi-Trailer: Michel Guillot1; Julien Nadeau2; Russell Long3; Jean-Christian Methot1; Charles Parenteau4; Mohamed Bouazara4; 1Laval University - REGAL Research Center; 2Alutrec Inc.; 3ALCOA Technical Center; 4Aluminium Research Center - REGAL Most commercial vehicles utilize thick plates and beams as structural members. Usually, they are made of steel and sometimes of aluminum to reduce their weight. Thin wall formed panels and extrusions have been proposed in the design a new aluminum 53 feet flat bed semi-trailer. The new shell design proposed is not only more aerodynamic and stiffer especially in torsion, but reduces the weight of the aluminum structure of the trailer by about 20% or nearly 700kg. This allows significant fuel economy and more important payloads. In this paper, the new shell design of the semi-trailer and its main characteristics are first presented. This design has been optimized to comply or surpass the performances of existingaluminum trailers. Finite element simulations have been realized to establish the deflections and stresses in the frame. One key element of this project, emphasized in the paper, is the use of thin walls and shell design. Although typically used in car, thin walls are uncommon in most commercial products. Accordingly, FE simulations and mechanical tests have been done to evaluate potential buckling, stress concentration in the gooseneck area and in connecting members, notably at welded joints. It was also necessary to ensure that the floor will not buckle or deform significantly under a localized load such as the front wheels of a fully loaded lift truck moving on the platform. At last, fatigue tests have been done to validate the welded assembly of the floor. Once assembled, the full scale prototype has been tested with static, dynamic and on-road experiments.

NEW TECHNOLOGY IMPLEMENTATION IN METALLURGICAL PROCESSES: Energy

Wednesday AM Room: Fontaine HOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Sina Kashani-Nejad, Hatch

8:55 AMEnergy Recovery from High Temperature Steel, Copper and Nickel Smelter Slags: Utigard Torstein1; T. Marin2; A. Warczok1; R. Bergman1; Mansoor Barati1; C. Diaz1; 1University of Toronto; 2Vale The world wide consumption of energy is steadily increasing and by 2030 it is forecasted to grow by another 50%, leading to mounting political and economic pressures. For any pyrometallurgical operation,it is therefore paramount to investigate and implement methods to decrease the use of energy. In the pyrometallurgical processing of steel, copper, nickel and other high temperature metals, a large amount of energy is lost in the hot off-gases, molten slags, mattes and molten metals. Most of this energy is generally lost during the cooling and solidification steps with very little focus on energy recovery or reuse.In this paper we will quantify how much energy is contained in the various slag streams, then review previous attempts and methods employed to recover some of this energy, and finally evaluate some novel technologies that could potentially be employed.

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9:20 AMNew Technology of Oxygen Evolution Anodes for Electrowinning: Masatsugu Morimitsu1; 1Doshisha University This paper introduces new technology of oxygen evolution anodes which can be applied to produce copper, zinc, cobalt, and other metals by electrowinning. The anode consists of nano iridium oxide particles dispersed in amorphous tantalum oxide matrix as a catalytic layer formed on a titanium substrate. The anode can reduce oxygen evolution potential by 0.25 to 0.55 V compared to commercially available lead alloy anodes and can suppress unwanted side reactions such as manganese oxyhydroxide, lead oxide, cobalt oxyhydroxide which occur during oxygen evolution. This smart anode can work for environmentally friendly electrowinning processes with low energy consumption and less anodic deposition.

9:45 AMAlternative Fuels for Metallurgical Processes: Preparation, Application and Process Design Considerations for Some Unconventional Fuels: E. A. Golebiowski1; Barry Hilchey1; 1Phoenix Process Engineering, Inc. Unconventional fuels can provide attractive alternatives to oil and gas in metallurgical processes to augment or provide the heat energy needed. Applications could be for ore dryers, roasters and rotary kilns. Unconventional fuels have been used to reduce or eliminate coal, natural gas and fuel oil usage in rotary and vertical kilns in the cement, lime, lightweight aggregate, refractory clay, and other industries for many years. Unconventional fuels include petroleum coke, shredded tires (TDF), waste liquids, and wood based solid fuels, such as saw dust, lignin and torrefied wood. Issues related to preparation and application of various alternative unconventional fuels are discussed. If pulverized fuel grinding is needed the system must be properly engineered to comply with applicable codes and to ensure safe and efficient operation.

10:25 AMNoranda/Teniente Copper Bath Smelting Process Variations - Impact on Energy Requirements: Pascal Coursol1; Carlos Dias2; Phillip Mackey3; 1Aluminerie Alouette; 2 ; 3Mackey Technology In a recent paper, the present authors discussed calculated energy consumption numbers in copper sulphide concentrate smelting for four different smelting technologies. For the present study, from among these technologies, they selected the Noranda/Teniente continuous bath smelting followed by Peirce Smith (PS) converting route to investigate the impact on total energy requirement of some key process variations, such as tuyere injection of dry concentrate vs. slingering of wet concentrate over the molten bath, continuous converting vs. conventional batch PS converting and commercially proven slag cleaning alternatives. In their calculations, the authors used the same thermochemical model and methodology used in their earlier paper. The results of these calculations provide a basis for evaluating flowsheet modifications that could lead to significant copper smelting energy savings.

10:50 AMOpportunities for Energy Savings and Energy Recovery using Indirect Heat Exchangers for Bulk Solids: Claudio Forniciov; Neville Jordison1; 1Solex Thermal Science Indirect, gravity flow, heat exchangers have become a well established technology in mineral and metallurgical process plants. The technology is a conventional heat exchanger using high efficiency plates, with a free flowing bulk solid on one side of the exchanger and a fluid on the other side. This simple concept leads to many opportunities for achieving greater energy efficiencies in process plants. Indirect heat exchange is much more efficient than direct heat exchange using air such as in a fluid bed or rotary device. When air is used directly, large fans are required, it may also be necessary to chill the air, both high consumers of energy. By contrast, using water as the cooling medium requires only low horsepower pumps, typically only 10% of fan HP. Furthermore there are no stack emissions with the requirement for removal of dust or emissions. Indirect heat exchange also creates the opportunity to recover energy. This can work in two ways: energy can be recovered from a hot bulk solid, to heat pressurized hot water

for steam generation or preheat air. Alternatively recovered energy from elsewhere in the plant in the form of hot water, steam, air or thermal oil can be used to preheat a bulk solid.

WASTE RECYCLING IN MINERAL AND METALLURGICAL INDUSTRIES: By-products Processing Effluents, Wastewater Treatment

Wednesday AM Room: VerdunOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Charles Jia, University of Toronto; Janice Zinck, CANMET

8:30 AMPretreatment of Silver Separated Residue by Alkaline Smelting at Low Temperature: Qinghua Tian1; Lizhen Cheng1; Xueyi Guo1; 1Central South University In order to recycle valuable metals comprehensively from silver separated residue (residue after recovery of gold and silver from copper anode slime), a novel method for using alkaline smelting at low temperature was proposed. The main factors affecting the main metal recovery such as the smelting temperature, smelting time, liquid-solid ratio and alkali addition were investigated comprehensively. And the behavior of main metal elements, such as Pb, Sn, Sb, in silver separated residue was also discussed. The results indicate that the amphoteric elements such as Pb and Sn can be smelted into the melt, while other metal elements, such as Cu is left in the residue.

8:55 AMHigh-Effective Process for the Preparation of a-Al2O3 Using Secondary Aluminum Dross as Raw Material: Xueyi Guo1; Fei Li1; Qinghua Tian1; 1Central South University A novel process for preparation of the a-Al2O3 from secondary aluminum dross was studied. The factors, including alkali dross ratio, salt dross ratio, smelting temperature, smelting time, leaching temperature, leaching time, and solid liquid ratio, were addressed on the transfer of Al into water soluble salt, and the feasibility of using seed precipitation as a successive treatment technology of leachate was discussed. The optimum conditions of the process were determine as follows: alkali dross ratio 1.3, salt dross ratio 0.7, smelting temperature 500�, smelting time 60min,leaching temperature 60�, leaching time 30min, solid-liquid ratio 1:4. The results show that leaching of aluminum reaches 92.71%, seed precipitation as a successive treatment technology of leachate is feasible and effective.

9:20 AMPossibilities for the Improvement of Secondary Zinc Oxide Quality: Stefan Steinlechner1; Gerald Schneeberger1; Jürgen Antrekowitsch1; 1University of Leoben Due to always getting stricter environmental legislations as well as increasing land filling fees the efforts for treating residues from metallurgy are continuously increasing. In case of filter dusts from metallurgical industry the high zinc bearing EAF-dusts or also dusts from copper secondary industry are important sources for the recovery of secondary zinc oxide. Because of low capacities for secondary zinc concentrates (like waelz oxide) in primary zinc metallurgy, the upgrade of such concentrates to a quality that meets the requirements of high quality (technical) zinc oxide becomes more and more important. This would open the opportunity to break into new markets and use it for example directly in electrolytic galvanizing. Therefore this paper will summarize possibilities for an elimination of halogens from secondary zinc oxides. Furthermore selective volatilization trials, with a synthetic mixture according to the analysis of waelz oxide, were carried out to remove impurities to achieve an upgraded product quality.

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9:45 AMEffect of Blending HDPE with Coke on the Reduction Behavior of a Manganese Oxide: Alexander Blagus1; Veena Sahajwalla1; 1University of New South Wales Research into using waste polymers in metallurgical processes has been underway over the last few decades, with the primary focus on polymer injection technologies for blast furnace and electric arc furnace steelmaking. The introduction of polymers into the EAF steelmaking process has shown several benefits including increased waste material diversion from landfills and enhancement in oxide reduction rates. This has led to the exploration of the possibility of using polymer/coke blends in the production of ferro-alloys, particularly High Carbon Ferromanganese (HC FeMn). These alloys are currently produced in submerged arc furnaces where coke/coal consumption reaches ~450kg/tonne of hot metal. This paper reports the effect of using a polymer (HDPE) blended with coke on the reduction behaviour of Mn3O4 (Hausmannite) at 1000°C. Experiments were conducted on compacted composite pellets containing varying amounts of Mn3O4, coke and HDPE. The pellets were introduced into the hot zone (1000°C) of a horizontal tube furnace. Analysis of the off-gas compositions and the microstructural and phase changes in the pellet were carried out. The results suggest that methane and CO contents in the off-gas increased, while CO2 contents decreased with increasing polymer addition and this had an impact on the manganese oxide reduction behaviour at 1000°C.

10:25 AMRemoval of Elemental Sulfur from Hydrometallurgical Waste Derived from Massive Sulfide Concentrates: John Halfyard1; Kelly Hawboldt1; Christina Bottaro1; 1Memorial University of Newfoundland The removal of sulfur from leach residues has been practised in the zinc industry using a combination of flotation and hot melt filtration. The process is highly dependent on the nature of the concentrate and the subsequent residue. When the mineral constituency of the concentrate alters, the process can encounter significant operational challenges. An alternate method of converting elemental sulfur to water-soluble polysulfides was applied to leach residue from Vale’s nickel demonstration plant in Argentia, Newfoundland. Reaction parameters, sulfur purity and other key indicators are discussed as is the potential commercial application.

10:50 AMSulphide Precipitation and Ion Exchange Technologies for Cost Effective Removal of Selected Metals in Wastewater: Alain Consigny1; 1BioteQ Environmental Technologies Alain Consigny BioteQ Environmental Technologies Canada New ?clean technologies? to treat mining and metallurgical effluents containing dissolved metals and sulphate have been successfully applied at mine sites in North America and Asia, treating water flows of up to 24,000 m3/day. These clean technologies offer significant benefits compared to conventional alternatives and provide a sustainable solution that eliminates residual waste sludge, improves water conservation, generates revenues from wastewater, and delivers overall improvements to the environment. Sulphide precipitation technologies use biological or chemical sources of sulphide to selectively precipitate dissolved metals, producing saleable metal by-products and clean water that can be safely re-used or discharged. This technology can remove up to 99% of dissolved metals from mining effluents, reducing metal concentrations to trace levels. Sale of the recovered metal products can offset treatments cost and deliver lower life cycle costs for water treatment. Ion-exchange processes use cationic and anionic resins to remove metals even where low levels of these metals (less than 15 mg/L) are present in a high flow of wastewater. The processes reduce TDS, achieve lower sulphate concentration levels than lime treatment, and produce a clean useful by-product that can be recycled. Ion-exchange processes consume less energy than membrane-based systems and deliver water recovery rates of up to 95%. This paper will profile these technologies, and provide best practice case study examples of their application at mining operations, including data for water chemistry, water flows, water quality, capital and operating costs, and life cycle costs of treatment compared to conventional treatment.

11:15 AMOffsetting Effluent Treatment Cost by Metal Recovery from Effluent Streams: Jacolien Wyethe1; Derrin Auerswald1; Nanne Vegter2; 1Bateman; 2Exxaro Base and precious metal refineries often produce effluent solution, and slurry, streams containing between 50 mg/L and several grams per liter of base metals. Metals have historically been precipitated from these streams with lime to produce effluent streams at pH values between 8 and 9. This effluent treatment process generally does not remove alkali and alkali-earth elements or halides efficiently and with more stringent environmental legislation, more sophisticated effluent treatment plants must be considered, which could for example incorporate sulphate removal with ultra-filtration, or the Savmin™ process, followed by reverse osmosis for the removal of halides. The flowrates of effluents are often high and if base metals can be recovered before neutralization, the revenue generated from this stream can reduce the cost to produce clean water significantly, and in the case where high concentrations are disposed of result in a profitable operation. As an add-on to an existing the plant the recovered metal is upgraded and recycled to the plant, but the production of a saleable metal can also be considered. Technology selection for metal recovery depends on the composition and flowrate of the effluent, but could incorporate resin-in-pulp or other ion-exchange technology; precipitation as sulphides, hydroxides or carbonates; or solvent extraction. This paper describes the technology selection process and uses data from Zincor, a subsidiary of Exxaro Base Metals (PTY) LTD, as a case study.

11:40 AMWaste Processing and Recycling: Some Case Studies: V.I. Lakshmanan1; R. Sridhar1; Raja Roy1; 1Process Research Ortech Inc. Recycling helps to save energy and it’s better for the environment. It is also important for preserving the limited natural resources. In addition, recycling creates economic benefits and frees up space at the landfill sites. Process Research Ortech Inc. (PRO) has conducted extensive testwork in the area of waste processing and recycling. A process was developed for the recovery of Zinc from galvanized steel by alkaline leaching followed by solvent extraction and electrowinning. Extensive testwork has been conducted at PRO to obtain useful by-product from rice husk. Rice husk was combusted in a gas/solid reactor to obtain an environmentally acceptable amorphous silica ash suitable for use in high strength concrete. In another development, vanadium was recovered from fly ash by separating carbon first, followed by alkaline pressure leaching, solvent extraction and precipitation. PRO has also developed an environment friendly process for treatment of industrial wastewater for its reuse to obtain zero or minimal effluent discharge. In this paper, four case studies related to recycling of zinc scrap, controlled combustion of rice husk, processing of fly ash, and reuse of waste water will be discussed.

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WORLD GOLD: Keynote II

Wednesday AM Room: Hampstead / Cote St. LucOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: David Lentz, University of New Brunswick

8:55 AM KeynoteGlobal Gold Resources – Past, Present and Future: Bruce Wilkinson1; Stephen Kesler2; 1Syracuse University; 2University of Michigan Mining provides ~2,500 tonnes (0.025 Mt) of new gold per year and has yielded ~0.17 Mt of gold since the early 1800s (www.gold.org). Reserves and resources of gold in known deposits (~0.13 Mt, Frimmel, 2008) will support current mining for several more decades, but significant new discoveries will be needed to sustain the present business model after that. Although the Witwatersrand gold deposits account for almost half of cumulative world gold production plus resources, their contribution to global gold production has diminished steadily over the last 50 years. Hydrothermal deposits, which have made up the shortfall, provide ~85% of newly mined gold today and will likely provide even more in the future. Our estimates indicate that hydrothermal deposits (with >1 t Au) throughout Earth’s entire crust contain as much as 6.8 Mt of gold. Only deposits in the upper 1 to 3 km will be accessible to discovery and mining, however. Of these, epithermal deposits contain ~0.39 Mt above 1 km and ~1.2 Mt above 3 km. Estimated gold contents to these depths are 0.52 and 2.7 Mt for porphyry copper deposits, 0.03 and 0.17 Mt for Carlin-type, 0.10 and 0.13 Mt for volcanogenic massive sulfide deposits, and 0.07 and 0.11 Mt for orogenic gold deposits. Other hydrothermal deposit types as well as magmatic deposits are unlikely to add much to this global total. Half or more of the gold in deposits to depths of 1 and 3 km will probably be impossible to discover or mine for reasons ranging from geologic to economic and environmental. If we can find 50% of the deposits above a depth of 1 km, gold mining might continue at present rates for ~200 years, a surprisingly short period compared to the 6000 years of historical gold mining.

WORLD GOLD: Mining-Maintenance and Engineering

Wednesday AM Room: Fontaine DOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: M. Harju

9:45 AMNRG1-ECOTM: Impact on Energy Savings and Air Quality: Sarah Paajanen1; Pat Dubreuil1; Amy Fortier1; 1BESTECH Increasing energy costs associated with mining have become an issue that must be addressed by industry to ensure sustainable production. As energy costs increase, initiatives to maximize the efficiency of all mining processes have increased in demand and feasibility of installation. BESTECH has developed the NRG1-ECO system in order to optimize energy usage within a mine. NRG1-ECO combines multiple methods of automatic and deliberate control in order to deliver a robust and agile system which addresses the need for reduction in energy consumption while providing a control system which can meet the requirements of an industry with a constant need for precision and safety. There are five control strategies which are used in the NRG1-ECOTM system to control systems and devices: Manual real time control; Time-of-Day Scheduling; Event-based control; Environmental control; Activity Based Control/Tagging. This paper discusses NRG1-

ECO’s application in Ventilation-On-Demand, the control strategies used in achieving ventilation on demand, and the proven benefits of the NRG1-ECO system as seen in some of its installations.

10:25 AMIs a Koepe Hoist Always a Better Solution?: Robert Townsend1; 1Hatch It is a widely accepted “fact” that a Koepe hoist is generally the best solution for production hoisting when compared to double drum hoists. This would appear to be true if one looks at the initial capital of just the hoist, and also compare the size of motor selected for the duty. But is this the whole story? What are the longer term “costs” involved in the hoists operation, and what are the relative efficiency’s of the two designs? Perhaps the Koepe hoist design enjoys a better reputation than it deserves.

10:50 AMMining Your Brain For Safety: A New Approach To Utilizing Your Best PPE: Marissa Afton1; Elizabeth Prazeres1; 1Sentis As we enter a new decade, the economic realities are more brutal than most of us can ever remember. Additionally, the demand for safer workplaces and the scrutiny from regulatory bodies has never been more intense, and dissatisfaction with safety performance by workers unions, employees, business stakeholders and governments grows stronger. In this climate, any investment we make in safety, simply must deliver results. It’s under these circumstances that high performing organizations are looking for new ways of doing business. They are seeking more than just short term interventions, but for an entirely new way to deliver their products in a safer, healthier, more environmentally responsible and efficient manner, and are turning to neuropsychology, the science of mind and brain, to find the answers. Worker safety and its impact are critical issues for production mangers-injury and incidents have direct effects on cost, schedule, quality, and company brand. In this context, considerable energy and effort over the past 20 years has been dedicated to researching and investing in workplace safety and safety culture (Guldenmund, 2000). Certainly, investments in engineering improvements (such as PPE, and ergonomic tools) and enhanced practices (field level risk assessments and innovative training) have yielded decreases in traditional lag indicator measures of safety, but only to a point. In order to establish effective and enduring organizational change in the mining industry, and to break through the safety plateau, we need first to look differently at what we are doing, and turn to the most resourceful of our protective equipment on hand-the human brain. It is in looking to the area of neuropsychology and its revealing studies of motivation, engagement, attention, and culture that will set the stage for the future and take safety to the next level.

11:15 AMEnergy Management Planning, Following the ISO 50001 Draft Standard: Klas Bockasten1; Dave Anders1; 1Golder Associates Energy-related issues are an increasingly important financial and strategic consideration. The understanding and control of energy related risks must be a priority not only for operational managers, but for the senior management and site managers of any organization that is concerned about corporate sustainability. ISO 50001 – Energy Management Systems (EnMS) is to be issued formally during the summer of 2011. EnMS is a voluntary international standard to transform businesses of all types and sizes into highly efficient energy users through continual improvement leading to reducing energy use, energy costs and related emissions. The paper will provide lessons learned from implementing and maintaining an Energy Management System typically saving 10-20% of energy within the first 5 years, in addition to the development and process for integrating EnMS into existing organizational culture. This includes developing energy management plans that are tailored to the specific needs of an organization and skilled training for building internal capacity for an effective implementation structure, long term financial benefits and reaching corporate social responsibility targets.

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WORLD GOLD: Mining III

Wednesday AM Room: Fontaine EOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Carol Plummer, Agnico Eagle

9:45 AMSome Observations on Corrosion of Support Systems in Selected Gold Mines: John Hadjigeorgiou1; Jean Dorion2; Edward Ghali2; 1Lassonde Institute, University of Toronto; 2Université Laval The objective of support systems is to keep an excavation open and safe throughout its useful life. Support should guarantee the security of personnel and equipment but also allow the operation to extract the ore as economically as possible. Corrosion of support systems can be a major safety and economic concern in underground gold mines. An improved insight on the factors that contribute to the corrosion of support systems in gold mines can aid in the selection of appropriate support strategies and a reliable assessment of the predicted useful life of a support system. This paper presents the results of on-going investigations on the influence of corrosion on the performance of support systems in selected underground gold mines. In underground mines, rock support is exposed to various conditions that can be aggressive like high relative humidity, dust and various particles, splashing of water and gases from the blasting and diesel equipment. Support components such as bolts, lattice, plate, retaining nut, cable ties can deteriorate due to atmospheric or aqueous corrosion. Conditions vary from one gold mine to another and also within a mine. This study focused on massive sulphite associated gold, and quartz veins bearing gold mines. This investigation addresses the influence of atmospheric corrosion, as well as the presence of bacteria on aqueous corrosion and the impact of microbiological corrosion on support systems. Samples of corroded support were analysed using SEM and photomicrography to determine the main corrosion forms. Tests are on-going in controlled corrosion chambers to qualify and quantify the impact of rock particles on steel corrosion. Eleven different kinds of minerals and rocks were tested in 100% humidity chambers at 24°C. Preliminary results suggest that it is possible to quantify the performance of support systems under corrosion.

10:25 AM KeynoteIntegrating Long- and Short-term Mine Planning through Stochastic Optimization and “Future Data” - Application and Comparissons: Arja Jewbali1; 1Newmont Mining Mine design and production scheduling based on stochastic optimization is a relatively recent development aimed at addressing uncertainty in ore supply from an orebody and metal demand. A new multistage stochastic mine production scheduling approach is presented and tested in an operating gold mine. In Stage 1, high density future grade control data is simulated and stochastically generated pre-existing simulated orebody models are updated. Stage 2 is based on a stochastic integer programming mine scheduling formulation that handles multiple simulated orebody models from Stage 1, and accommodates both maximizing net present value and minimizing deviations from production targets. Stage 3 includes quantification of risk in the produced schedules generated, comparison of schedules, and reporting. The application at an operating gold mine demonstrates that the approach is shown to deliver additional ore (3.6 Mt more) and metal (2.6 Mt more) which matches the mined reconciliations and results in a cumulative NPV which is on average 7.7 million dollars higher than that of a stochastic schedule without the simulated future drilling, and substantially higher (about 30%) compared to the NPV from the actual schedule of the mine.

10:50 AMStochastic Optimization of Ultimate Pit using a Modifies Network Flow Algorithm: Application at a Gold Deposit: Jeroen van Eldert1; 1TU Delft Open pit design and production scheduling is an intricate process that defines the sequence of ore and waste extraction during the life-of-mine and up to an ultimate pit limit. This process deals with the management of cash flows in the order of hundreds of millions of dollars. Uncertainty in the metal/ore and waste forecasted to be produced from a pit has a major financial impact in both valuations and operation. To deal with this uncertainty, a new push re-label minimum cut algorithm is tested in an application at a gold mine. The push re-label algorithm is implemented on the so-called directed graph, formulated from the simultaneous use of a set of multiple stochastically simulated models of the orebody representing the related uncertainty. This leads to the definition of the optimal pit limits under uncertainty in ore/metal supply from the orebody; and for a given set of other engineering inputs. In addition, pushbacks can be similarly designed by parametrizing the space of the orebody. The application at an epithermal vein hosted gold deposit finds its optimal pit limits. This is then generated along with pushbacks, and results assessed for feasibility, risk, and NPV. The comparison to the conventionally derived design (commercial implementation of the Lerchs-Grossman algorithm) shows that the method presented here generates a larger pit and about 30% higher undiscounted economic value.

WORLD GOLD: New Concepts I

Wednesday AM Room: Hampstead / Cote St. LucOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: L. Lorenzen, Snowden

9:45 AMModelling of the Gold Content within the Size Intervals of a Grinding Mill Product: Claude Bazin1; Mohammad Khalesi2; 1Laval University; 2 Batch grinding tests conducted on a gold ore indicated that gold is not randomly distributed within the size fractions of the ground ore. Since gold leaching performances were found to be dependent of the size of the gold carrying particles the development of integrated gold ore grinding-leaching model should incorporate a method to predict the gold size distribution in a ground ore. The paper describes the results obtained from batch grinding tests showing the distribution of gold within the size interval of a ground ore and the initial development of a grinding simulator to predict the gold size distribution in a batch grinding product.

10:25 AMPotential of Sensor-Based Sorting for the Gold Mining Industry: Christopher Kleine1; Hermann Wotruba1; Mathilde Robben1; Lütke Ketelhodt2; Matthew Kowalczyk3; 1RWTH Aachen University; 2CommodasUltrasort (Pty) Ltd; 3CommodasUltrasort Decreasing reserves, water shortages, increasing energy costs, environmental and social constraints are challenges that have to be answered with innovative machines and methods. Sensor-based sorting is a financially and technically viable technique that is operating with little or no water and relatively little power consumption. Sensor-based sorting has already proven its operational stability at two Gold applications in South Africa. An optical sorter has been applied to upgrade waste dumps of Witwatersrand conglomerate Gold Ore in 2003 and 2004, turning those already mined resources into reserves. Same happened in 2009 where an X-Ray-Transmission sorter was applied to upgrade the dense media separation tailings of massive sulfide type Gold ore at Pilgrim’s Rest. Currently a “clean and green” processing plant is erected at Kloof mine including three optical sorters and a Gekko Python density separation plant. Sensor-based sorting cannot only turn waste dumps and diluted

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mining blocks into reserves. The implementation can also cause a decrease in specific operating costs of mill and mine when for example replacing selective mining by bulk mining methods with subsequent sorting. Results of test work done on a Witwatersrand run-of-mine gold ore underline this potential of mine-to-mill integration applying sensor-based sorting. Current research is conducted on the potential of near-infrared-spectroscopy sorting at Gold applications. Correlations between the occurrence of near-infrared active alteration minerals and ore related phases in Iron Oxide Copper Gold systems are present. Those correlations, which are nowadays used for exploration, can be transferred to sorting algorithms. Successful installations, operational experience, test work data and flow sheet integration from mine-to-mill underline the impact and potential that sensor-based sorting can have on the Gold mining and processing industry. The potential is far from being exploited.

10:50 AMRecent Process Additions at the Royal Canadian Mint 2005-2011: Vicken Aprahamian1; Rod Beauprie1; Terry Cheng1; Michael Tangen1; 1Royal Canadian Mint The Royal Canadian Mint has undergone significant changes in the form of new process additions since 2005. Implementation of a whole new highly automated silver refining circuit has allowed recovery of physical silver from gold and silver dorés . To complement this change, a small Top Blown Rotary Converter has been in operation. On the gold refining side, a new hydrometallurgical Miller Chlorination slag treatment circuit has been developed. In addition to a waste water treatment system, wet and dry fume and dust collection systems have been installed.

11:15 AMGold Powder Technology: A Review: Hossein Aminian1; 1FiMatCon Gold powders have many important industrial applications. In this paper the available processes for the preparation of gold nano and micron sized powders are described. The attention has been given to hydrometallurgy route and the recent works and achievements in controlling the powder morphology are highlighted.

WORLD GOLD: New Concepts II

Wednesday AM Room: Mont RoyalOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: M. Jefferey, not available

9:45 AMKinetics of Cyanide Oxidation under CIP or CIL Conditions: Xianwen Dai1; Paul Breuer1; Matthew Jeffrey1; 1CSIRO Within the CIP or CIL cyanidation processes, a decrease in cyanide concentration occurs as a result of several possible mechanisms: oxidation, volatilization, and formation of metal cyanide complexes followed by adsorption onto activated carbon. Commonly the cyanide loss is measured during leach testwork, with a number of studies having attempted to correlate the cyanide loss with ore characteristics and/or operating parameters. However, none have attempted to differentiate the loss of cyanide via oxidation from the other mechanisms. Of particular concern is the potential increase in cyanide oxidation in the presence of both carbon and copper. This paper presents results from a study in which the oxidation of cyanide was determined from the change in solution cyanate, the oxidation product, which is stable in alkaline solutions and does not adsorb onto activated carbon to any appreciable extent. Investigated is the effect of carbon, oxygen and copper concentrations and cyanide to copper mole ratios from 2:1 to 15:1. Results show that the oxidation of free cyanide and copper cyanide complexes follow a first order reaction. In the absence of carbon the oxidation of cyanide proceeds very slowly, whilst in the presence of carbon the oxidation of cyanide is substantially enhanced and increases with increasing carbon concentration. For the carbon catalysed oxidation,

it has been found that the oxidation of the Cu(CN)2- complex is the most difficult, followed by the oxidation of free cyanide and then Cu(CN)32-. When there is co-existence of both free cyanide and copper (i.e. CN:Cu>3), the oxidation proceeds most readily and increases with both copper and free cyanide concentrations.

10:25 AMSignificant Innovations in the Australian Gold Industry: Damian Connelly1; 1Mineral Engineering Technical Services Pty Ltd Significant Innovations In The Australian Gold Industry By Damian Connelly Director/Principal Consulting Engineer Mineral Engineering Technical Services Pty Ltd (METS) www.mets.net.au [email protected] ABSTRACT This paper details a brief history of the Australian gold industry from the 1980s gold boom to the present day, highlighting an industry characterised by innovation in plant design and junior companies prepared to ?have a go? in contrast to the conservatism of many larger mining companies. Design flexibility, the innovation of new processes, the preparedness to exchange ?process know how? and technology singularly differentiated the gold industry from other sectors over during the 1980s. The introduction of tight footprints, large plants and equipment, two stage crushing, SAG milling and pebble crushing, mill innovations, carbon in pulp (CIP) and carbon in leach (CIL), stepped tanks to flat tanks, the scale up challenges of large tanks and mixers, the North Kalgoorlie screen, carbon management systems, the development of a number of stripping systems, various electrowinning regimes and modularisation were all exciting changes in the industry. Australia can compete globally in the resource sector despite its high wage structure. This is the result successful implementation of process innovation and design changes. Research and development plus innovation by companies themselves and assistance from consultants has resulted in Australia becoming a leading supplier of commodities and an exporter of resource sector technology. Institutions such as Queensland University?s Julius Kruttscnnitt Mineral Research Centre, Perth based Parker Centre, the University of South Australia?s Ian Wark Institute, and CSIRO, AMIRA and the Cooperative Research Centres (CRCs) have fostered these innovations. Over the last thirty years there have been widespread innovations and process design changes.

10:50 AMPilot-Scale and Continuous Bench Testing of the MMS CN-D Cyanide Destruction Process on an Australian Gold Plant Tailings Effluent: Mike Adams1; Stuart Glen; 1Maelgwyn Australia Pty Ltd Cyanide management practices on modern gold plants are becoming more onerous, due to environmental pressures, particularly for signatories to the International Cyanide Management Code. Operations are therefore seeking to reduce levels of weak-acid dissociable (WAD) cyanide reporting to spigot discharge as well as to any eventual discharges from the tailings storage facility (TSF).Current gold industry standard processes primarily include the oxidation of cyanide by means of sodium meta-bisulfite (SMBS, or SO2) with air, Caro’s acid (H2SO5) or hydrogen peroxide (H2O2). These processes require the transport and usage of expensive oxidizing reagents, along with the safety and environmental issues associated with these corrosive and toxic chemicals. Maelgwyn Mineral Services (MMS) has developed the MMS CN-DTM process, which utilizes the Aachen ReactorTM, a high-energy mass-transfer superoxygenation system, in conjunction with an activated carbon-based catalyst and no additional reagents, to increase the rate of cyanide oxidation to cyanate, the thermodynamically more stable form. Testwork conducted at the Maelgwyn Australia testwork facility in Perth Australia is described, at both pilot scale and continuous bench-scale, on a sample of tailings effluent obtained from an Australian gold plant. WAD cyanide is demonstrated to be lowered using the MMS CN-DTM process from an influent of 130 mg/L to the required levels for discharge to TSF (<50 mg/L). The continuous test results showed stable operation over three residence time turnovers. The pilot-scale results demonstrated the efficiency of the process at the reasonably large scales required for engineering cost estimation.

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11:15 AMIn-Situ Leaching (ISL) of Gold Deposits: Damian Connelly1; 1Mineral Engineering Technical Services Pty Ltd In-Situ Leaching (ISL) process plants are low cost producers for uranium deposits where the geology is suitable. In the 1970s, a three-year pilot ISL program occurred on gold ore from the Ajax Mine, Cripple Creek District, Colorado, using a chloride and iodide solution. [1] The test was halted due to poor results. With gold and silver the international ISL progress has been slow; however the potential for low CAPEX and OPEX with large low grade deposits is real. Unless the metallurgy has been demonstrated there are significant risks which could be fatal flaws to an ISL gold or silver project. The metallurgy of gold and silver ISL projects is far from simple and it is early days with project development.

LIGHT METALS: Aluminium Transformation IV

Wednesday PM Room: LachineOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Grant Chen, Aluminium Research Centre - REGAL, UQAC; Sumanth Shankar, McMaster University

2:00 PMPredicting Misruns in LPPM Casting of Light Metal Parts (Aluminum A356 and Magnesium AZ91E): Franco Chiesa1; Nicolas Giguère1; Bernard Duchesne2; Jocelyn Baril3; 1Centre de Métallurgie du Québec (CMQ); 2Collège de Trois-Rivières; 3Technologies du Magnésium et de l’Aliminium Experimental results on thin and thick castings poured in aluminum A356 and magnesium AZ91E by the low pressure permanent mold process have been compared to the result of filling simulations. If the results of modeling is reliable when the liquid remains above the liquidus temperature, it is no longer the case when partial solidification occurs. The visco-elastic behavior of a partially solidified liquid is difficult to put into equation as it depends on the amount of shear to which the fluid has been subjected. Attempts to predict misruns using a commercial software have proved to be very difficult if not impossible; divergence of the numerical solution has been observed unless prohibitively long computing times are used. In order to overcome these practical difficulties, a simple method is proposed which consists in tracking the temperature of the advancing liquid metal front so as to make sure it will always remain above the so-called ‘Misrun Critical Temperature’ (MCT) determined experimentally for thin and thick aluminum A356 and magnesium AZ91E castings. If the predicted liquid metal front temperature falls below MCT, a cold-shut or misrun is likely to occur at this location.The values of MCT for thin and thick in aluminum A356 and magnesium AZ91E were determined experimentally on misrun castings of widely different geometries: a thin 2mm wall cover and a 6mm to 25mm thick bell housing. MCT was found to be lower for magnesium AZ91E and for the thicker casting (bell housing).

2:25 PMHot Workability Differences of 7000 Aluminum Alloys with and without Copper Additions: Hugh McQueen1; Paola Leo2; 1Concordia University; 2University of Salento The Al-Zn-Mg alloys (e.g. 7004, 7020) are employed for land transport and architectural applications whereas the Al-Zn-Mg-Cu alloys (e.g. 7075, 7050) provide the high strength aircraft alloys. The Cu gives rise to suitably sized and distributed precipitation but causes high quench sensitivity. Their hot work processing also has marked differences; the Cu-free alloys have good extrudability whereas the Cu-bearing alloys have low extrudability and are difficult in rolling as well. The behaviors of the two classes are described in terms of flow stresses and ductility over 300-500°C, along with constitutive contrasts. The ductility of the alloys with Cu is much reduced above 400°C by precipitation of a phase at the grain boundaries

that can be avoided by suitable heating schedules. The high strength alloys are subject to delamination corrosion of sheared edges due to severely pancaked grains; this can be alleviated by holding between passes in mid-rolling schedule. In torsion tests at 10-1 to 10 s-1/ 250-500°C, the stresses (ductilities) at 300°C/ 1s-1 and activation energy Q for 7004 were 118 MPa (2 ) and 262 kJ/mol. The 7075 was tested after several pretreatments:: completely overaged (softened): 107 MPa (5), Q=150 kJ/mol; whereas, solution and quick cooling to testing caused extraordinarily high peaks related to dynamic precipitation resulting in 160 MPa (1.2), Q=300 kJ/mol.

2:50 PMCanadian Hot Workability Research on Al Alloys 1960 - 2010: Hugh McQueen1; Gordana Avramovic-Cingara2; 1Concordia University; 2McMaster University Before 1950, hot working was simply deforming above the recrystallization point and gave a soft product compared to cold working. From 1960 onwards, improved testing in compression and torsion (stress, strain rate, temperature, quenching) provided valid specimens for microstructural analysis by polarized optical and transmission electron microscopy (TEM). Indeed, TEM was essential to uncovering the hot working mechanisms because it could distinguish between cold and hot substructures (dynamic recovery) in either initial or new grains (dynamic recrystallization). Over the years, teams at Concordia, McGill and UBC obtained NSERC support for students and equipment. CANMET built up a hot forming group having capabilities from high-rate cam-plastometer compression to rolling of experimental alloy billets; this was combined with latest metallographic instruments for fundamental research. Al alloys of every class (2000, 3000, 5000, 7000, 8000) were studied to understand the effects of solutes, precipitates, dispersoids and composites. The complex flow patterns in extrusion were clarified and modeled by finite element methods. Physical simulations of rolling schedules (up to 20 passes and reductions of 98%) by torsion provided evidence of microstructure development during both the passes and the softening intervals, thus clarifying development of texture in different alloys. The results frequently appeared in proceedings of Light Metals symposia and Canadian Metallurgical Quarterly

3:15 PMMicrostructure and Hot Workability of Al-Mg-Si Alloy in the As-Cast and Homogenized State: Paola Leo1; Hugh McQueen2; Emanuela Cerri1; 1Università del Salento; 2 Concordia University Al-Mg-Si alloys are widely used as medium-strength structural materials; extrusion is the most common processing route. In the present hot deformation investigation of a 6060 alloy, the microstructure of the alloy has been analyzed in the as-cast state, after homogenization heat treatment and after hot deformation by tensile tests in the range 400-490°C and 10-4 to 10-2s-1 on both as cast and homogenized alloys. After deformation the microstructure of the as-cast alloy exhibited cavitation. The flow curves at the lowest test temperature T show a gradual softening after a stress peak, being more evident for the alloy deformed in the homogenized state in association with a high yield stress; at higher T a plateau is attained which is lower as T rises and strain rates decrease. For each fixed T, the ductility decreases as strain rate increases for the homogenized alloy whereas, for the as cast alloy, it rises with strain rate. Constitutive analysis gives Q = 240kJ/mol for the homogenized alloy in agreement with published values; this indicates a more rapid strength decline with rising T than Al, suitable for good hot workability along with the lack of cavitation.

3:55 PMExperience in the Heat Treatment of Pressure Die Cast Brackets: Nicolas Giguère1; Franco Chiesa1; Jean-Francois Blackburn2; 1Centre de métallurgie du Québec (CMQ); 2Cégep de Trois-Rivieres Until recently, the heat treatment of pressure die cast parts has always been considered unpractical because the solution heat treatment resulted in unacceptable blistered parts. This was due to the presence of massive porosity associated with the die casting process where the inflow of metal inside the mold cavity is extremely turbulent. Due to the steady improvement of foundry practices and the generalization of vacuum die casting, porosity defects have been reduced to the point that a partial solutionizing heat

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treatment can be applied without any damage to the casting. However the solutionizing temperature must be lower than that applied to macroporosity free castings and for mulch shorter time. The object of the present study is to determine the highest solutionizing temperature that can be applied to aluminum 383 die cast brackets along with the optimal tmeprtature anf time of aging resulting in the highest improvement in mechanical properties. (both strength and ductility). This will be done by testing strength and deformation on the casting itself using a specially designed jig; the crushing force to deformation curve will be analyzed so as to quantify the improvement in both strength and ductility brought about by the partial precipitation hardening heat treatment.

NEW TECHNOLOGY IMPLEMENTATION IN METALLURGICAL PROCESSES: Modelling

Wednesday PM Room: Fontaine HOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Boyd Davis, Kingston Process Metallurgy Inc.

1:35 PMRole of Process and Logistics Simulation Modeling in Delivering Capital Effective and Operationally Efficient Solutions for RTFT: Cassandra Lee1; Jeff McGinty1; Yves Pepin2; Gabriel Issid2; 1Hatch; 2Rio Tinto Fer et Titane Over the past decade, Hatch has used process and logistics models to assist Rio-Tinto Fer et Titane (RTFT) with capacity planning, debottlenecking, and optimization to help ensure design capability, capital effectiveness, and operational efficiency of the integrated production chain. Process models are used to optimize the physics-based aspects of the system, such as mass and energy balances, flow rates, yields, and equipment specifications. Dynamic logistics models are used to optimize how the various plant areas work together to achieve the desired ends and deal with such things as plant scheduling and synchronization strategies, sizing of buffers between processes, defining the required number of process and material handling units, and designing a plant layout that minimizes plant interferences and inefficiencies. The combined use of process models and logistics models enables the overall plant to be optimized from both a productivity and quality point of view, with each plant area working in harmony with one another to achieve targeted capacities and efficiencies. This paper describes the many benefits derived from such modeling efforts over the past decade for each of the major plant areas at RTFT: QIT ‘s Steel Plant, Slag Plant, and Smelter Plant, and QMP’s Powder Plant.

2:00 PMThermodynamic Modelling of Peirce-Smith Converter Slag at the Chagres Smelter, Chile: Nubia Cardona Valencia1; Roberto Parra F.1; Luis Bahamondes2; P. J. Mackey3; Philip J. Mackey3; 1University of Concepción; 2Chagres Smelter, Anglo American PLC; 3P.J.Mackey Technology Inc. The Chagres smelter in Chile, a unit of Anglo American, utilizes an Outokumpu flash furnace and Peirce-Smith converters to produce 92,000 tpy of anode copper. Two, fuel oil-injected rotary slag cleaning vessels are used to clean converter slag before the slag is discarded. Typically, Peirce-Smith converter slag from the matte blows (matte grade is 62% Cu) is transferred to the slag cleaners (along with flash furnace slag), while the high copper slag from the copper blow is normally cooled and recycled to the flash furnace as cold dope. The performance of the slag cleaning furnaces is dependent in part on the quality of the converter slag. In order to understand the impact of converter slag quality on slag cleaning and to help optimise the slag cleaning operation, thermodynamic modelling of the converter slag, supported by microscopic examination and electron probe microanalysis (EPMA)of industrial slag samples, was carried out to characterize the Peirce-Smith converter slag. The results of this investigation are described in this paper.

2:25 PMAdvanced Integrated Process Modelling of Ni-Cu Sulphide Treatment at Xstrata Nickel’s Sudbury Smelter: Nagendra Tripathi1; Rajan Pandher1; Arthur Barnes1; Ron Schonewille2; 1Xstrata Process Support; 2Xstrata Nickel Advanced process modelling tools were developed for the Xstrata Nickel Sudbury Smelter flow sheet using a combination of FACTSAGE?, METSIM? and ARENA? software. These tools were employed to assist with plant optimisation, emission control, process design and case studies as applied to a smelter. The development of process modelling tools in pyro-metallurgy commonly involves an in-depth study of the thermo-chemical properties (heat capacity, liquidus temperature, etc) of all high temperature phases, usually matte and slag. The preferred tool for this purpose is FACTSAGE?, a well-known thermo-chemical modelling software package. In this work, the results from the thermo-chemical model have been subsequently incorporated into the development of a process model for the entire smelting facility using the METSIM? platform. Such a process model also includes a number of special features adopted to effectively simulate matte and slag systems. To ensure the robustness and reliability of the process model, several process parameters and assumptions were verified with laboratory and plant data. Consequently, the model includes the ability to examine the impact of a number of plant parameters on potential plant performance. Potential variables are the percent sulphur elimination during concentrate roasting, furnace matte grade and degree of matte metallization. Key output parameters include operating temperature, furnace coke requirement, sulphuric acid production, CO2 emissions and overall energy requirements. Selected outputs from the process model (for example blowing time, slag production rate and matte converting rate) can then be utilised in the development of a discrete event model (DEM) for the smelter using ARENA? software. Incorporation of reliable and validated mass balance parameters enhances the robustness and reliability of the DEM model. The integration of thermo-chemical, process and DEM modeling tools has a distinct advantage in planning plant trials and examining process design initiatives at the Xstrata Nickel Sudbury smelter.

2:50 PMDevelopment of the System for Furnace Integrity Monitoring Based on Real-Time Continuous Acoustic Emission Data Acquisition and Analysis: Pawel Gebski1; Afshin Sadri1; Winnie Ying1; 1Hatch Industrial smelting furnaces are subjected to significant structural changes and deterioration caused by the conditions under which they operate. The current methods for the structural assessment of furnaces are mainly focused on visual inspections, thermal data analysis, acousto ultrasonic-echo (AU-E) of the refractory lining and surveying of the key structural elements. Acoustic Emission (AE) non-destructive testing (NDT) technique has proven its capabilities for continuous monitoring of industrial installations and structures. Recently, Hatch Ltd. has been successful in applying AE for monitoring furnace tapblocks, and expanding the scope of the AE monitoring to the structural integrity of the entire furnace. The capability of detecting emissions related to the fracture development in the furnace shell, movement of the refractory, electrode arcing, combined with efficient source location algorithms makes an AE system a comprehensive tool for the real-time furnace integrity monitoring. In this paper the concept of such state of the art structural integrity assessment system is presented. The initial results of the AE monitoring together with data analysis techniques are also discussed.

3:15 PMElectric Furnace Freeboard Combustion CFD Modeling: Amir Golpaygan1; 1Hatch Poor combustion efficiency, roof and/or side wall overheating, carry over to off-gas system and non-ideal radiative heat transfer to processes or cooling systems have been common limiting factors causing inadequate process performance of the furnace, operational problems, and safety hazards. Application of Computational Fluid Dynamics (CFD) modeling for simulating fluid flow and combustion in industrial scale electric furnace will be presented. This paper will describe how CFD simulations can be

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used to address commonly observed problems associated with freeboard combustion. Examples will be presented to explain how combustion CFD modeling has been used as a tool to diagnose a problem with furnace (roof overheating), optimize existing design (air infiltration distribution) or develop a new design (freeboard furnace scale-up).

3:55 PMImproving Energy/Water Specific Consumption Strategies in Industrial Complexes: Integration and Collaboration: Osvaldo Bascur1; Curt Hertler1; 1OSIsoft, LCC The lack of integrated information including the Energy/Utility Suppliers with sufficient detail for analysis causes inefficient operation in metallurgical complexes including the Energy/Utility Suppliers . Defining the right context for information use is essential for sustainable operations. This being said, what are we doing to enable people to act upon information and to be aligned to optimize the use of resources like raw materials, energy, water and consumables for an entire metallurgical complex? Collaboration between all company entities is a key component of improving efficiency. Evolution of web technology and object modeling of enterprise assets enables collaboration across the whole business. Operational troubleshooting occurs more quickly as the organization acts on issues to reduce wasteful operation. This paper presents a real time software infrastructure with tools that give users the ability to sift through available data, transform data into information for business continuous improvement and optimization. We will introduce a new technology for analyzing real time data, information and events using multidimensional analysis of information to detect anomalies based on the statistics of the data classified by time events to reduce the information into action. A new paradigm for collaboration at a local and strategic level is proposed to enable the enterprise to become proactive in dealing with wasted time and products. Three examples from the industry will presented and their benefits highlighted.

4:20 PMModeling & Software for Control Purposes of a Direct Blister Smelter: Mikko Korpi1; Jouni Pihlasalo1; Peter Björklund1; Lauri Pesonen1; Tuula Mäkinen1; 1Outotec (Finland) Oy Outotec Direct Blister Flash Smelting technology has proved to be an efficient and environmentally friendly way to treat the copper concentrates from the Zambian Copper belt at Konkola Copper Mines’ (KCM) Nchanga smelter in Zambia. The earlier applications of this technology are Olympic Dam smelter (Australia) and KGHM smelter (Poland) with quite different raw material base and customized process concepts. The process chain comprises of a direct blister furnace combined with two-stage electric furnace slag cleaning to recover blister copper and Cu-Fe-Co alloy. Lime and limestone are used as the fluxing agent producing an iron-calcium-silicate slag.The modeling of slag chemistry and thermodynamics with MTDATA software played a central role in deciding the operation parameters as well as in quickly overcoming metallurgical challenges in slag chemistry during the commissioning of the Nchanga smelter. The high oxide slag in the blister furnace as well as the low oxide slag in the electric furnaces is required to achieve a sufficiently low viscosity at acceptable temperatures. Outotec FSF Online Process Advisor, a process control model and a monitoring tool for a Flash Smelting Furnace, is used to calculate the process parameters and to give valuable information of the process state for operation personnel. Online Process Advisor automatically transfers information between the process control model, the process control system and the laboratory. The control model enables correct process parameters to stabilize the process operation. After the implementation of the online version of Process Advisor the process control improved significantly. Steadier process conditions also helped decrease Cu content in the slag, minimizing Cu carryover to the electric furnaces. The model also predicts the melt level, which helps to optimize the tapping schedule and the feed rate. It also seeks a ternary CaO-FeOx-SiO2 diagram of liquidus temperature that corresponds with the latest operation point.

4:45 PMRisk Weighted Cash Flow, a Communication Tool for Engineers and Financial Professionals on New Technology Projects: Mark Kennedy1; Cameron Harris2; Allan MacRae3; 1Norwegian University of Science and Technology; 2SNC Lavalin Inc.; 3MacRae Technology Inc. New technology projects, particularly those involving first-of-a-kind metallurgical facilities, have a poor track record of achieving their overall financial targets, as they incorporate technological risks in addition to normal project risks. Traditional project management tools focus on risk from concept development through implementation, but typically fail to address the additional risks associated with a new technology project including slow start-up, slow ramp-up, and failure to achieve design performance (quality or throughput). These additional risks affect future cash flows produced by the project and hence its value, typically measured as net present value (NPV) or internal rate of return (IRR). Common accounting practice is to reduce the present value of future cash flows by applying a chosen discount rate, often reflecting the corporation’s cost of capital. This discount rate does not contain an allowance for technological risk, which is often underestimated or misunderstood by both the financial and engineering project managers. This paper will focus on the topic of project risk and new technology, and how these play a role in the probability of achieving the predicted future cash flows. By properly addressing technological risk in the form of risk-weighted returns, marginal projects can be prevented from proceeding, while sound projects can be given the additional time and resources required to achieve the optimal level of front-end-loading (the level which returns the maximum risk-weighted net present value). A simple set of mathematical tools should enable engineers and financial professionals to establish a common level of understanding, thereby leading to a more accurate assessment whether a new technology project is ready to pass through its next level of approvals.

5:10 PMThe Importance of Process Control to New Technology Implementation: Terry Gerritsen1; Sylvain Picard1; Bruce MacKay1; 1Hatch Virtually all new technologies require a control system. Any intense process has many process variables that react quickly making manual control difficult. Control system design has a significant impact on the success of a plant especially during ramp-up. New technology projects are particularly sensitive to control system design as the process response is unknown. This paper discusses the important factors encountered in the design of a control system for a new technology. Examples are given of successful new technology plant start-ups where tight coordination of the process control system implementation, process design and selection major equipment led to rapid ramp-ups.

WORLD GOLD: Fundamentals

Wednesday PM Room: Hampstead / Cote St. LucOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chairs: Nathan Stubina, Barrick Gold; M. Adams

2:00 PMFundamental Investigations of SART for Cyanide and Copper Recovery: Andrew Simons1; Paul Breuer2; 1Parker Centre/CSIRO/Curtin University; 2CSIRO The presence of soluble copper in the ore can be a problem for many gold operations. This is due to copper consuming at least three moles of cyanide per mole of copper to form toxic copper cyanide species, which are discharged into the tailings storage facility unless treated. The SART (Sulfidisation, Acidification, Recycle, and Thickening) process can overcome this problem as it can separate copper and cyanide from each other in clarified tailings solutions. Cyanide can then be recycled while copper is recovered as a high grade copper sulfide precipitate. This paper

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will discuss the results of factorial experimentation conducted on the SART process, the focus being the influence of process variables on SART performance and control. A key finding of this work is that cyanide and copper recovery decrease over time due to loss of sulfide from the system as hydrogen sulfide gas. An economic analysis of these results is also presented showing optimal operating conditions and profit sensitivity based on reagent costs. Finally, this paper will show how a variety of common species found in gold tailings respond to SART and the implications of their response. This includes the possibility of selectively recovering other metals from gold tailings including residual gold and silver as well as toxic elements such as arsenic, antimony, and mercury.

2:25 PMThe Dissolution of Chalcocite and Covellite in Cyanide Solutions: James Kyle1; Paul Breuer2; Khin Aye1; Rebecca Meakin2; 1Murdoch University (Parker Centre); 2CSIRO Gold is often associated with copper ores, and during copper sulphide flotation, the gold only partially reports to the flotation concentrate with the remainder in the flotation tailings. In such cases, the flotation tailings are often treated with cyanide to recover the accessible gold. During this process the copper minerals in the flotation tailings, generally in concentrations in excess of the remnant gold, will also dissolve competing with the gold for cyanide and adsorption space on activated carbon. In addition, the soluble copper must be removed from the tailings water prior to recycle. As well as consuming large amounts of cyanide by the formation of complexes containing up to four moles of cyanide per mole of copper, the dissolution of copper minerals in cyanide solutions also results in cyanide losses by oxidation to thiocyanate and dissolved oxygen reduction in the solution by the oxidation of the sulfide ions. In this paper, the dissolution of chalcocite and covellite in cyanide solutions is examined under both anoxic and oxic conditions, and the concentration of copper, cyanide and sulfur species have been determined during the course of the reactions. This has lead to a new interpretation of the dissolution mechanisms for both copper sulfides in cyanide solutions.

2:50 PMAn Electrochemical and SERS Study of the Gold-thiosulfate Interface in the Presence of Copper: Eric Nicol1; Janet Baron1; Jeff Mirza1; Jacek Lipkowski1; Yeonuk Choi2; 1University of Guelph; 2Barrick Gold Corporation Due to recent concerns over the environmental impact, and toxicity of cyanide, much research has gone into the use of thiosulfate as an alternative lixiviant for gold leaching [1,2]. The addition of Cu (II) into the leaching solution has been shown to aid in gold dissolution and is believed to aid in partial removal of the passive layer forming on the gold surface [3]. Although it is known that addition of Cu (II) is beneficial, the exact mechanism by which it aids in the oxidation and dissolution of gold, and its role in determining the composition of the passive layer formed, remain unknown. The main goal of this project is to understand the role Cu (II) plays in the promotion of leaching over passivation. Results presented will stem from work accomplished using Surface Enhanced Raman Spectroscopy (SERS) in tandem with electrochemical techniques such as linear and cyclic sweep voltammetry. Electrochemical measurements show how the mixed potential shifts as Cu (II) aids in the oxidation of gold and partially removes oxysulfur species or sulfur from the gold surface. SERS spectra collected were used for fingerprint identification of sulfur species on the surface of the gold in an attempt to pinpoint which species promoted leaching over passivation. Due to the destructive nature of the leaching reaction, the SERS spectra were acquired using gold nanorod electrodes that showed increased stability compared to other SERS active surfaces.

3:15 PMPyrite Encapsulation in the Neutral/Alkaline Pressure Oxidation of Refractory Gold: Samuel Peters1; Vladimiros Papangelakis1; 1University of Toronto Pressure oxidation of refractory gold ores can be conducted on ores with high carbonate content using just water or water with alkaline reagents

to promote fast kinetics, and suppress the formation of elemental sulphur and CO2. In this work, a fundamental study was conducted to explore the silica-pyrite interaction in the presence of calcium and sodium carbonate. It was found that an alkaline environment increases the pyrite decomposition kinetics on one hand, but on the other dissolves silica, which encapsulates the dissolving pyrite thus hindering ultimately it complete decomposition.

3:55 PMThe Deportment of Trace Toxic Elements in Cyanide Solutions: James Kyle1; Vera Gella1; Peter May1; 1Murdoch University (Parker Centre) The deportment and speciation of trace elements during mining and minerals processing is becoming an area of increasing concern with regards to potential health and environment risks within the immediate vicinity and surrounding area of mining and minerals processing operations. In Australia, the National Pollutant Inventory (NPI) lists antimony, arsenic, beryllium cadmium, chromium (III&VI), cobalt, copper, cyanide, lead, manganese, mercury, nickel, selenium and zinc as monitoring targets. The use of chemical modelling can enhance our basic understanding of the deportment and speciation of trace metals under conditions present in gold processing solutions, and assist in laboratory and field investigations. In this paper, we report the results of chemical speciation modelling using the JESS software package for the trace toxic elements Pb, Cd, Hg, As, Sb, Bi, Se and Te in cyanidation solutions of varying salinity and relate the models to experimental data. The speciation of mercury cyanide species is examined in detail to assist in determining itd deportment throughout the gold cyanidation process. While the use of chemical speciation software can assist in understanding the deportment of these trace toxic elements in cyanide solutions, caution must be used in interpreting the models produced which must be related to the information in the software database.

4:20 PMCyanide Analysis for Complex Cyanide Solutions: Wendy van der Merwe1; Paul Breuer2; 1Mintek; 2Australian Minerals Research Centre With the gold industry looking to process more complex ores, the control of cyanide addition to the gold leaching circuit has become more crucial. On-line “free” cyanide measurement provides a rapid response to changes in ore mineralogy, however poor understanding of the various cyanide analysis methods has impaired their acceptance and uptake within the gold industry. This paper compares the two commonly employed “free” cyanide online analysis methods (amperometric and potentiometric end-point silver nitrate titration) with the common site laboratory rhodanine endpoint silver nitrate titration method and those obtained using an ion selective electrode. Some interferences, method considerations and measurement differences between these methods will be presented and discussed. Particular focus will be on cyanide solution containing copper and zinc with varying cyanide to metal ion ratios and the resulting cyanide available to leach gold.

WORLD GOLD: Geology III

Wednesday PM Room: Fontaine DOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: David Lentz, University of New Brunswick

2:00 PMThe Gold Content of Volcanogenic Massive Sulphide Deposits: Patrick Mercier-Langevin1; Mark Hannington2; Benoît Dubé1; Valérie Bécu1; 1Geological Survey of Canada; 2University of Ottawa VMS deposits contain variable amounts of gold, both in terms of average grade and total contents. The analysis of gold grades and tonnages of 513 VMS deposits worldwide revealed that a large proportion of deposits are characterized by a relatively low gold grade (<2 g/t), with a gradual decrease in frequency towards maximum grades. The geometric mean and geometric standard deviation appear to be the simplest metric for identifying subclasses of VMS deposits based on gold grade. The geometric mean gold

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grade is 0.76 g/t; the geometric standard deviation is +2.70 g/t Au. Deposits with more than 3.46 g/t Au (geometric mean plus one geometric standard deviation) are considered auriferous. The geometric mean gold content is 4.7 t Au, with a geometric standard deviation of +26.3 t Au. Deposits containing 31 t Au or more are considered to be anomalous in terms of gold content, irrespective of the gold grade. Deposits with more than 3.46 g/t Au and 31 t Au are considered gold-rich VMS. A large proportion of the total gold hosted in VMS worldwide is found in a relatively small number of such deposits. The identification of these truly anomalous systems helps shed light on the geological parameters that control unusual enrichment of gold in VMS. At the district scale, the gold-rich deposits occupy a stratigraphic position and volcanic setting that commonly differs from other deposits of the district possibly due to a step change in the geodynamic and magmatic evolution of local volcanic complexes. The gold-rich VMS are commonly associated with transitional to calc-alkaline intermediate to felsic volcanic rocks, which may reflect a particularly fertile geodynamic setting and/or timing (e.g, early arc rifting). At the deposit scale, uncommon alteration assemblages (e.g., advanced argillic) and trace element signatures are present, suggesting a direct magmatic input in some systems.

2:25 PMAu-Rich Volcanogenic Massive Sulphide Deposits of the Flin Flon Belt, Manitoba and Saskatchewan: Alan Galley1; Patrick Mercier-Langevin1; 1Geological Survey of Canada In the present economic climate where bulk tonnage, low grade gold-rich deposits are a principal target for global exploration, volcanogenic massive sulphide deposits remain a viable exploration target where they contain abundant gold. There continued viability is due to both their polymetallic nature and high precious metal grades (Au and Ag) which allow companies to be buffered against swings in single commodity prices. Several Paleoproterozoic greenstone belts are host to Au-rich VMS systems, including the Flin Flon Belt accreted arc terranes in north-central Manitoba and Saskatchewan. These Au-rich VMS deposits are located within more evolved, rift-related volcanic arc assemblages in which abundant felsic magmatism is represented by both rhyolite flow complexes and more extensive volcaniclastic units. These are terranes are usually more calc-alkalic in nature, within a differentiated volcanic sequence that includes andesite and rhyodacite. They are characterized by an aluminosilicate-rich alteration assemblage and zones of pervasive silicification not dissimilar to epithermal gold deposits. Within the metamorphosed and strongly deformed arc terranes of the Flin Flon Belt the gold is commonly redistributed along syn-kinematic structures, thereby complicating reconstruction of their original morphology and metal zoning. They are found spatially related to “normal” bimodal mafic and bimodal felsic VMS deposits within the same camp.

2:50 PMStratigraphy, Mineralogy, Geochemistry, and Genesis of the Au-Rich Volcanogenic Massive Sulfide (VMS) System from the Baie Verte Peninsula, NW Newfoundland, Canada: The 1806 Zone as an Example from the Ming Mine, Rambler Camp: Stefanie Brueckner1; Stephen Piercey1; Paul Sylvester1; Larry Pilgrim2; Stephanie Maloney2; Darrell Hyde2; George Ogilvie2; 1Memorial University of Newfoundland; 2Rambler Metals & Mining Canada Ltd. The 1806 Zone is one of several newly discovered mineralization zones in the early Ordovician Ming Mine, Rambler Mining Camp, Baie Verte Peninsula, NW Newfoundland, Canada. The Ming Mine is a metamorphosed, bimodal-mafic Cu-Au-(Zn-Ag) VMS deposit hosted within the Dunnage Zone, Newfoundland Appalachians. The 1806 Zone

(~ 487,000 t @ 0.64% Cu, 1.01% Zn, 3.40 g/t Au, and 22.31 g/t Ag) has a footwall dominated by variably altered and mineralized rhyolitic flows and volcaniclastic rocks, and a hanging wall consisting of turbidites, all cut by altered mafic dykes. Alteration in the rhyolitic footwall zone is characterized by sericite-quartz±green mica and near the sulfide-hanging wall contact, silicification commonly occurs. Sulfide mineralization occurs as stringer, semi-massive and massive sulfide lenses and is dominated by pyrite, chalcopyrite, sphalerite and metamorphic pyrrhotite, with lesser galena, arsenopyrite, tetrahedrite, and electrum. Ore microscopy, scanning electron microscopy (SEM), and electron microprobe (EMP) data reveal a complex ore mineralogy including electrum, various Ag-phases (e.g., acanthite, pyrargyrite), sulfosalts (e.g., tetrahedrite-tennantite, stannite, boulangerite), and oxides (e.g., cassiterite, magnetite), in addition to the above sulfide phases. Electrum ranges from sub-µm to mm sized occurring with most sulfide phases, including: (1) as a free phase; (2) along grain boundaries and in veinlets; and (3) as inclusions in sulfide phases. Gold, Ag, and Hg are enriched up to several hundred g/t in almost all sulfide phases with core to rim zoning in pyrite and arsenopyrite with Au-rich rims and Ag-rich cores. Sphalerite occurs as Fe-rich and Fe-poor varieties, but there is no correlation between precious metals and Fe content. Enrichment in Au and Ag in the 1806 Zone and Ming VMS deposit is explained by synvolcanic mineralization with a magmatic contribution to the hydrothermal ore fluid. Later deformation and upper greenschist grade metamorphism only remobilized and upgraded Au within the VMS deposit.

3:15 PMForm, Distribution, and Genesis of Gold in Volcanogenic Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick: Sean McClenaghan1; David Lentz2; 1New Brunswick Department of Natural Resources; 2University of New Brunswick Gold is an important commodity in Zn-Pb-Cu-Ag-type volcanogenic massive sulfide deposits of the Bathurst Mining Camp. The average Au content of massive sulfides is 0.8 ppm, but can reach up to 6.9 ppm in the Caribou deposit. The 329 Mt Brunswick No.12 deposit represents the largest concentration of sulfides, with historical resources of 124 Mt grading 8.8% Zn, 3.5% Pb, 0.4% Cu, and 103 g/t Ag. Mill feed for the Brunswick No.12 deposit typically ranges from 0.5 to 0.7 g/t Au, although Au contents of up to 8.2 ppm Au have been identified in hanging wall sulfide lenses. Several deposits in the BMC also exhibit higher average Au contents, notably the Caribou (Avg., 1.7 ppm), Restigouche (1.6 ppm), and Louvicourt (2.4 ppm) deposits. Gold correlates positively with Ag, As, Sb, and Sn, which tend to be concentrated in the exhalative Zn–Pb-rich bedded sulfide facies. Footwall stockwork and Cu-rich replacement (zone refining) zones are enriched in Cu, Bi, Co, and Se, and contain less Au, on average. Secondary-ion Mass Spectrometry and Laser-ablation ICP–MS analyses of sulfide grains confirm the refractory nature of Au, with elevated Au contents in pyrite (up to 42.9 ppm) and arsenopyrite (up to 10.9 ppm), whereas sphalerite, galena, and chalcopyrite have Au contents that are below detection. Concentration of Au likely occurred through exhalative processes in response to mixing of high-temperature hydrothermal fluids with seawater. Zone-refining processes were also responsible for some remobilization of Au, resulting in the sharp enrichment of Au with Sb, Sn, and Ag towards the stratigraphic hanging wall of many massive sulfide deposits. The strong enrichment of Au in primary pyrite (colloform) masses supports a syngenetic paragenesis of Au, whereas lower concentrations in porphyroblasts and late idiomorphic rims, indicate limited release of refractory gold during greenschist facies metamorphism.

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WORLD GOLD: Pregrobbing/Recovery

Wednesday PM Room: Mont RoyalOctober 5, 2011 Location: Hilton Bonaventure Hotel

Session Chair: Adrian Giblett, Newmont

2:00 PMEvaluation of Preg-Robbing in Goldstrike Carbonaceous Ore Using Raman Spectroscopy: Michelle Helm1; J Vaughan1; W Staunton1; 1Curtin University (Parker Centre) The application of Raman spectroscopy to characterise and predict the preg-robbing behaviour of carbonaceous ore is an innovative application of existing technology. It has been used to demonstrate that the physical structure of graphitic carbon found in these ore’s plays an important role in influencing preg-robbing behaviour. Using the Raman spectra of the graphitic carbon, with reference to the spectra from activated carbon, a simple and robust technique referred to as the Raman Calibration Line (RCL) has been established to predict preg-robbing capacity (Helm et al 2009). The present study, which forms part of an ongoing investigation, evaluates the RCL and its ability as a predictive tool to manage the deleterious influence of carbonaceous material on gold recovery at Barrick Gold’s Goldstrike property in Nevada. To date, 24 samples sourced from various locations within the Goldstrike property have been investigated. The samples have graphitic carbon concentrations ranging between 0.38 and 5.88 %, with absolute preg-robbing capacities ranging between 1.0 and 880 grams of gold per ton of ore. In order to make a direct comparison between individual samples, the absolute preg-robbing capacities of each sample were normalised to a graphitic carbon concentration of 1 %. The graphitic carbon concentration was found to correlate poorly with preg-robbing values, indicating other properties influence preg-robbing behaviour. The Raman spectra of the graphitic carbon indicated that varying degrees of disorder existed among the samples, and furthermore, this disorder showed a correlation with the noted variation in preg-robbing. Application of the RCL technique highlighted significant variability in the structure of graphitic carbon present at Goldstrike which could be attributed to its geological history. The investigation of the RCL then clearly demonstrated the technique as effective in providing predictions of a samples preg-robbing behaviour.

2:25 PMDeportment of Toxic Trace Elements in the CIP/CIL Cyanidation Process: Paul Breuer1; Karl Bunney1; Ron Pleysier1; 1CSIRO The deportment of toxic trace elements is an area of increasing concern to the mining industry as mineral processing can concentrate toxic elements, presenting hazards to both personal health and the environment. Historically toxic trace elements such as arsenic (As), antimony (Sb), selenium (Se), tellurium (Te), mercury (Hg), lead (Pb), cadmium (Cd) and bismuth (Bi) have been investigated, with an aim of reducing by-product penalties in commodities such as base metal concentrates, and more recently, increasingly to meet environmental regulations. Antimony, arsenic, beryllium cadmium, chromium (III&VI), cobalt, copper, cyanide, lead, manganese, mercury, nickel, selenium and zinc are listed by the Australian National Pollutions Inventory (NPI) as monitoring targets. This paper presents results from studies into the deportment of a range of trace elements within the CIP/CIL cyanidation process used for the recovery of gold. Investigated is the solubility of these elements in cyanide solutions of varying pH and salinity, the adsorption of the soluble elements onto activated carbon from these cyanide solutions and the precipitation of the soluble elements during cyanide treatment.

2:50 PMCIL Gold Extraction from Preg Robbing Autoclave Discharges: Gus Van Weert1; Yeonuk Choi2; 1ORETOME Limited; 2Barrick Gold Corporation

In the spring of 2010 double refractory ores from historical stockpiles were processed through Barrick’s Goldstrike pressure oxidation facility, thereby providing preg robbing feeds for a variety of metallurgical testwork. This paper describes the effects of amount, type, place and time of addition of activated carbons on CIL gold recovery and shows that native carbon in plant POX’ed discharge solids can still preg rob gold loaded activated carbon.

3:15 PMGold Preg-Robbing by Silicates in Chloride Media: Sima Mohammadnejad1; John Provis1; Jannie van Deventer1; 1The University of Melbourne The preg-robbing potential of framework and layer silicates in a chloride medium and in the absence of activated carbon is examined. Experiments are conducted on quartz, feldspar, kaolinite and pyrophyllite powders (0.1-2.5 µm) under acidic and alkaline conditions (pH 2.5-8). The adsorption of gold in acidic media is strong for all silicates evaluated. The overall uptake of gold per unit mineral surface area decreases in the following order: pyrophyllite, quartz, kaolinite, feldspar. The amount of sorbed gold is much more closely related to the specific surface area rather than the type of silicate at acidic pH (pH 2.5 to 3). In weakly alkaline conditions (pH 8), the adsorption is weak for all silicates except pyrophyllite. Reversibility analysis at pH values of 0-1 does not show any gold trapped or physisorbed on silicate surfaces, indicating that chemisorption is the primary mechanism of gold loss from solution. The mechanism of adsorption can be proposed to involve an attraction between the positively charged surfaces of silicates and anionic gold chloride species, which means that the degree of adsorption is greatly reduced in an alkaline environment where the silicates carry a net negative charge and thus do not attract the anionic gold complexes. The correlation between the dissolution of silica from the minerals and the loss of gold from solution may also be an indication that gelation of dissolved silica is causing entrapment and/or adsorption of gold from the solution. The chemisorption mechanism is also evaluated by XPS analysis of the loaded silicate surfaces.

3:55 PMFunctionalized Mesoporous Silica: An Effective Adsorbent for the Uptake of Gold Thiosulfate: Louis Mercier1; Adil Aledresse2; François Desmarais1; Rashmi Narendrula1; Laxman Amaratunga1; 1Laurentian University; 2GoldCorp Thiosulfate is recognized as a promising alternative lixiviant to cyanide for the extraction of gold from ore bodies. Gold thiosulfate, however, is not well-adsorbed by activated charcoal, making industrial scale use of thiosulfate for gold leaching impractical at present. Because of their high specific surface areas and uniform open-framework nanoporosity (pore channel diameters in the range 3-10 nm), functionalized mesoporous silicas are widely recognized as highly effective materials for the selective, rapid and high capacity uptake of mercury, gold and platinum group ions. In the present work, the efficient adsorption of gold thiosulfate by thiol-functionalized mesoporous silica (hereafter designated MP-HMS) is demonstrated, whereby the thiol groups in the materials bind with the gold complexes by ligand displacement. Under slurry conditions in the range 0.25-1.00 g MP-HMS per L of gold thiosulfate solution (10 ppm at pH in the range 7-10), 53-95% of the gold was adsorbed within 30 minutes of exposure. The adsorbed gold could be leached out using cyanide, regenerating the adsorbent for further uptake cycles. Functionalized mesoporous silica is thus a promising candidate for the preconcentration of gold from thiosulfate leachate solutions.

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Abdelhakim, D ................................................ 20Abe, M ............................................................ 33Abrokwah, E ................................................... 21Acar, S ............................................................. 33Adams, M .................................................. 43, 46Adham, K .......................................................... 3Afton, M .......................................................... 41Ajersch, F ........................................................ 28Al Ahmari, A ................................................... 28Al-Ahmari, A ................................................... 18Alamdari, H ............................................... 2, 7, 8Alam, S ........................................................... 33Aledresse, A .................................................... 49Allaire, A ......................................................... 16Allard, B ............................................................ 8Allen, L ........................................................... 16Alvear Flores, G .............................................. 30Amaratunga, L ................................................ 50Amidi, S .......................................................... 10Aminian, H ...................................................... 43Ammar, H ........................................................ 18Amsden, J ........................................................ 31Anders, D ........................................................ 41Antrekowitsch, J ....................................... 12, 39Aprahamian, V ................................................ 43Archambault, Y ............................................... 38Argyropoulos, S ........................................ 27, 28Arthur, P .......................................................... 30Asselin, E ........................................................ 37Auerswald, D .................................................. 40Avramovic-Cingara, G .................................... 44Aye, K ............................................................. 47Azari, K ......................................................... 7, 8

B

Baggag, A ........................................................ 26Bahamondes, L ................................................ 45Baldwin, S ....................................................... 12Balladares, E ................................................... 24Barati, M ......................................... 2, 24, 31, 38Bardoux, M ..................................................... 34Baril, J ............................................................. 44Barnes, A ............................................. 10, 15, 45Baron, J ..................................................... 37, 47Barus, R........................................................... 10Bascur, O ......................................................... 46Bax, A .............................................................. 25Bazin, C ........................................................... 42Beauprie, R ..................................................... 43Bécu, V ............................................................ 47Beier, J ............................................................ 21Bellec, S .......................................................... 34Bergman, R ..................................................... 38Besson, J ......................................................... 20Bhambani, T .................................................... 22Bhambhani, T .................................................. 22Bhargava, D .................................................... 20Bhimavarapu, S ............................................... 20Bilodeau, J ....................................................... 26Birur, A .......................................................... 3, 8Björklund, P .................................................... 46Blackburn, J .................................................... 44Blagus, A ......................................................... 40Blanpain, B ..................................................... 23Blatter, P ............................................................ 6

Bockasten, K ................................................... 41Borden, R ........................................................ 24Borle, S ............................................................. 8Bottaro, C ........................................................ 40Botz, M ........................................................... 26Bouajila, A....................................................... 25Bouazara, M .................................................... 38Bouchard, J ..................................................... 25Bouchard, N ...................................................... 2Bouzahzah, H .................................................. 14Boyd, D ............................................................. 9Breault, R .......................................................... 2Breuer, P .................................. 36, 43, 46, 47, 49Brienne, S ........................................................ 11Brochu, M ............................................. 9, 21, 30Brophy, S ........................................................... 9Brueckner, S .................................................... 48Bruening, R ..................................................... 34Bruno, L .......................................................... 29Bucknam, C ..................................................... 25Bui, H .............................................................. 18Bunk, S ............................................................ 31Bunney, K ....................................................... 49Burton, P ......................................................... 36Bussmann, M .................................................. 28Bustamante, M .................................................. 5Buzatu, P ......................................................... 38

C

Cabri, L ..................................................... 13, 14Caetano de Lima, M ........................................ 11Cao, X ........................................................... 3, 8Caratini, Y ....................................................... 26Cardona Valencia, N ....................................... 45Carrasco, J ....................................................... 24Castro, C ......................................................... 10Cayouette, J ....................................................... 6Celovsky, S ..................................................... 17Cerqueira Souza Solimani, L .......................... 11Cerri, E ............................................................ 44CHAOUKI, H ................................................... 7Charette, A ....................................................... 27Charmier, F ..................................................... 26Chatwin, T ................................................. 24, 25Chen, G ........................................................... 44Cheng, L .......................................................... 39Cheng, T .......................................................... 43Chen, H ........................................................... 18Chen, J............................................................. 20Chen, T ............................................................ 32Chen, X ................................................. 3, 27, 28Chevarin, F ........................................................ 8Chiang, Y ........................................................ 11Chieregati, A ................................................... 16Chiesa, F ................................................... 19, 44Chin, E .............................................................. 2Chinnasamy, S ................................................. 14Choi, Y .......................................... 25, 37, 47, 49Chouinard, C ................................................... 36Chromik, R ........................................................ 3Chychko, A ...................................................... 31Coley, K .......................................................... 22Collins, L ........................................................... 9Collins, M ................................................. 10, 15Comtois-Parr, M .............................................. 19Connelly, D ............................................... 43, 44Connolly, J ...................................................... 35

Constable, M ................................................... 34Consigny, A ..................................................... 40Coulombe, M .................................................... 8Coursol, P .................................................. 10, 39Cousin, P ......................................................... 14Cox, D ............................................................. 17Csicsovszki, G................................................. 37Cuddy, J ......................................................... 3, 8Cutler, J ........................................................... 13

D

Dai, X .............................................................. 43Dai, Z .............................................................. 23Dalgaard, E ....................................................... 8Dankwah, J ...................................................... 23Daoust, C......................................................... 13Dave, N ........................................................... 29Davis, B........................................................... 45D’Elia, F .......................................................... 19Demopoulos, G ............................................... 12Dernedde, E ....................................................... 2Deschenes, G ..................................................... 5Deschênes, G ................................................... 26Désilets, M ........................................................ 7Desmarais, F ................................................... 49Desrochers, A .................................................. 38Deysel, K ......................................................... 14Dias, C............................................................. 39Diaz, C ............................................................ 38Diaz-Sandi, G .................................................. 23Dicker, J .......................................................... 23Dimitrakopoulos, R ............................... 6, 16, 42Dimov, S ..................................................... 5, 15Djebara, A ....................................................... 18Dodbiba, G ........................................................ 5Doerr, D ............................................................ 6Donald, J ......................................................... 10Dorion, J .......................................................... 42Douglas, I .................................................... 7, 16Doutre, D ......................................................... 28Doyle, L .......................................................... 29Dragusanu, C ................................................... 35Drake, T ............................................................ 6Drumhillers, H ................................................ 17Dubé, B ........................................................... 47Dubreuil, B ...................................................... 36Dubreuil, P ...................................................... 41Duchesne, B .................................................... 44Duchesne, C ...................................................... 8Duck, P ............................................................ 16Dufour, G .................................................. 37, 38Dunne, R ......................................................... 33Dupont, J ......................................................... 16Dupuis, M ................................................... 7, 26Dutrizac, J ....................................................... 12

E

Eccleston, E ..................................................... 31Edmison, D ..................................................... 21Ellis, T ............................................................... 4Elsayed, A ....................................................... 19Eltringham, G .................................................... 4Esbensen, K ..................................................... 16Evatt, G ........................................................... 16

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Fafard, M ........................................... 7, 8, 18, 26Farhat, R .......................................................... 30Finch, J ............................................................ 22Fisk, D ............................................................. 10Fleming, C............................................. 6, 15, 26Ford, K ............................................................ 26Forget, L .......................................................... 19Forniciov, C. .................................................... 39Fortier, A ......................................................... 41Fortier, M ........................................................ 27Fortin, C .................................................... 33, 38Fortin, J ........................................................... 38Freeman, N ...................................................... 10Frydrychewicz, A ............................................ 37Fujita, T ............................................................. 5Fulton, M......................................................... 26

G

Gaborit, L ........................................................ 34Gaboury, D ...................................................... 35Gagnon, C ....................................................... 25Gakwaya, A ..................................................... 18Gallant, D ........................................................ 27Galley, A .......................................................... 48Gallienne, D .................................................... 37Gaudreault, V .................................................. 27Gauthier, P ....................................................... 27Gauvin, G ........................................................ 26Gavin, G .......................................................... 31Gebski, P ................................................... 10, 45Gella, V ........................................................... 47Geoffroy, N ..................................................... 12Gerlich, A .......................................................... 8Gerritsen, T ..................................................... 46Ghali, E ..................................................... 27, 42Gholipour, J ................................................... 3, 8Giblett, A ................................................... 25, 50Giguère, N ....................................................... 44Glen, S............................................................. 43Golebiowski, E ................................................ 39Golpaygan, A ................................................... 45Gordon, R ........................................................ 35Gougeon, P ........................................................ 3Grama, A ......................................................... 27Grande, T .......................................................... 8Guerin, M .......................................................... 8Guillot, M .............................................. 9, 18, 38Güntner, J ........................................................ 15Guo, J ................................................................ 3Guo, M ............................................................ 23Guo, X ......................................................... 4, 39Gurung, M ....................................................... 33

H

Habashi, F ......................................................... 2Hacini, L ...................................................... 7, 26Hadjigeorgiou, J .............................................. 42Halfyard, J ....................................................... 40Hamel, G ........................................................... 2Hammerschmidt, J .......................................... 15Haneman, B ....................................................... 4Hannington, M ................................................ 47Han, Y ............................................................. 27

Hardtke, W ...................................................... 16Harju, M .......................................................... 41Harris, B ...................................................... 6, 36Harris, C .......................................................... 46Harrison, R ...................................................... 30Harrison, S ...................................................... 12Hart, B ......................................................... 5, 15Hasenbank, A .................................................. 10Hawboldt, K .................................................... 40Heard, D ............................................................ 9Hekmat-Arkakan, A ........................................ 28Helm, M .......................................................... 50Henderson, R ............................................... 6, 16Henein, H .......................................................... 9Hertler, C ......................................................... 46Hewitt, B ......................................................... 10Hilchey, B ....................................................... 39Hinds, M ......................................................... 14Hiruta, K ......................................................... 33HIRUTA, K ..................................................... 32Holmstöm, A ................................................... 15Holywell, G ..................................................... 20Hoseini, M....................................................... 20Hosoi, A........................................................... 33HOSOI, A ........................................................ 32Howel, S .......................................................... 16Hyde, D ........................................................... 48Hyland, M ................................................... 2, 27

I

Imani, Y ............................................................. 9Inostroza, C ................................................. 2, 17Inoue, K ........................................................... 33Isac, M ............................................................. 19Issid, G ............................................................ 45Itoh, M............................................................. 32Ivey, D ............................................................... 9Izadi, H .............................................................. 8Izatt, N ............................................................. 34Izatt, S ............................................................. 34

J

Jackson, S ........................................................ 14Janse van Rensburg, S ..................................... 25Jefferey, M ...................................................... 43Jeffrey, M ........................................................ 43Jewbali, A .................................................... 7, 42Jia, C ......................................................... 23, 39Johnson, P ....................................................... 16Jonas, J .............................................................. 8Jones, D ........................................................... 15Jones, M .......................................................... 36Jones, P .............................................................. 7Jones, R ........................................................... 10Joshi, S ............................................................ 37

K

Kabir, A ............................................................. 3Kalanchey, R ................................................... 15Kamguem, R ................................................... 28Kang, J ........................................................ 8, 21Kappes, R .................................................... 6, 33Kapusta, J .................................................... 3, 21Kashani-Nejad, S ............................................ 38

Kato, T ............................................................ 33KATO, T .......................................................... 32Kawakita, H .................................................... 33Kayali, E ......................................................... 28Kekesi, T ......................................................... 11Kelebek, S ....................................................... 33Kennedy, M ..................................................... 46Kenne, J ........................................................... 28Kesler, S .......................................................... 41Ketelhodt, L .................................................... 42Khalesi, M ....................................................... 42Khanna, R ....................................................... 23Khettabi, R ................................................ 18, 28Khokhar, M ..................................................... 19Kinver, P............................................................ 5Kipper, D ......................................................... 11Kirby, B ..................................................... 17, 21Kirkham, G ............................................... 13, 34Kleine, C ......................................................... 42Knapp, S .......................................................... 22Knights, D ....................................................... 23Kondos, P .................................................. 15, 31Kongkarat, S ................................................... 23Koppalkar, S .................................................... 25Korovin, V ...................................................... 11Korpi, M .......................................................... 46Kouam, J ................................................... 18, 20Kowalczyk, M ................................................. 42Kretschmar, U ................................................. 35Kulcsar, T ........................................................ 11Kuwauchi, Y.................................................... 24Kyle, J ............................................................. 47

L

Lacroix, M ......................................................... 7Lagueux, J ....................................................... 16Lakshmanan, V ............................................... 40Lalancette, J .................................................... 36Lamb, T ........................................................... 37Langlois, V ...................................................... 27Laroche, D ....................................................... 26Larose, S ........................................................... 8Larouche, D ..................................................... 26Lauzon-Gauthier, J ............................................ 8Lawrence, R .................................................... 25Lebeuf, M .......................................................... 8Leclerc, S .......................................................... 2Lee, C .............................................................. 45Lefebvre, L ...................................................... 38Lefrançois, L ................................................... 27Lemieux, D ..................................................... 36Lentz, D ............................................... 41, 47, 48Leo, P .............................................................. 44Lévesque, J ...................................................... 18Li, F ................................................................. 39Lind, P ............................................................. 31Ling, D ............................................................ 23Lipkowski, J .............................................. 37, 47Liu, Q .............................................................. 34Lombardi, A .................................................... 19Long, R ........................................................... 38Lopez, D ............................................................ 6López, O .......................................................... 25Lorenzen, L ..................................................... 42Luckita, A ........................................................ 10Lumsden, B ..................................................... 11Lun Sin, S........................................................ 19

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Machin, A ........................................................ 19Machuca Mory, D ........................................... 16MacKay, B ...................................................... 46MacKay, R ...................................................... 19Mackey, P ...................................... 21, 29, 39, 45MacRae, A ....................................................... 46Madi, Y............................................................ 20Maheshwari, A ................................................ 20Mäkinen, T ...................................................... 46Makni, S .......................................................... 25Maloney, S ...................................................... 48Marcuson, S .................................................... 22Marin, G .......................................................... 19Marin, T .......................................................... 38Marion, P ......................................................... 14Marois, M .......................................................... 7Martel, R ......................................................... 12Martens, J ........................................................ 11Martinez-Gutierrez, H ..................................... 23Martinez-Morales, C ....................................... 23Maslouhi, A ..................................................... 38Masounave, J ............................................. 18, 28Masters, I ......................................................... 15Matei, M .......................................................... 18Mayhew, K ...................................................... 15May, L ............................................................... 3May, P ............................................................. 47McClenaghan, S .............................................. 48McDermid, J ................................................... 21McGinty, J ....................................................... 45McLean, A ....................................................... 23McQueen, H ................................................ 9, 44Meakin, R ........................................................ 47Medraj, M ................................................... 3, 19Meesschaert, B ................................................ 11Mercier, L ........................................................ 50Mercier-Langevin, P ................................. 47, 48Mermillod-Blondin, R............................... 14, 15Methot, J ......................................................... 38Mezbahul-Islam, M ......................................... 19Mezei, A .......................................................... 30Millos, R ......................................................... 21Mindivan, H .................................................... 28Mirazimi, S ..................................................... 11Mirjafari, P ...................................................... 12Mirkhani, K ..................................................... 10Mirnezami, M ................................................. 22Mirza, A ............................................................. 4Mirza, J ..................................................... 37, 47M. Murenbeeld, M .......................................... 36Moger, L .......................................................... 12Mohammadnejad, S ........................................ 49Mooruth, N ...................................................... 13Morgeneyer, T ................................................. 20Moriarty, J ....................................................... 16Morimitsu, M .................................................. 39Moryoussef, P ................................................... 7Muñoz, F ......................................................... 10Murray, K ........................................................ 15

N

Nadeau, F .......................................................... 3Nadeau, J ......................................................... 38Nagaraj, D ....................................................... 22Nakamura, T .................................................... 32

Narendrula, R .................................................. 49Naseri Joda, N ................................................. 33Nava-Alonso, F ............................................... 37Nicol, E ........................................................... 47Nyholt, J .......................................................... 36Nzotta, M ........................................................ 31

O

Ogilvie, G ........................................................ 48Ohto, K ............................................................ 33Ojo, O .............................................................. 21O’Kane, P ........................................................ 23Oki, T ................................................................ 4Olifirenko, A .................................................... 11Ono, H ............................................................... 5Orangi, S ........................................................... 7Ospina, M ........................................................ 36Ourriban, M ....................................................... 6Owada, S ......................................................... 32

P

Paajanen, S ...................................................... 41Pandher, R ....................................................... 45Pangeni, B ....................................................... 33Papangelakis, V ............................................... 47Parada, F ......................................................... 24Parada, R ......................................................... 24Parenteau, C .................................................... 38Parra F., R........................................................ 45Parra, R ........................................................... 24Patoine, M ....................................................... 30Patra, P ............................................................ 22PATRA, P ........................................................ 22Peacey, J .................................................... 30, 37Peevers, R ......................................................... 7Pekguleryuz, M ............................................... 20Pelletier, P ......................................................... 6Pelton, R .......................................................... 23Peña, C .............................................................. 5Penniston, C ...................................................... 9Pepin, J ........................................................ 9, 21Pepin, Y ........................................................... 45Perry, B ........................................................... 16Pesonen, L ....................................................... 46Peters, S........................................................... 47Pham, T ........................................................... 18Picard, D ........................................................... 7Picard, S .......................................................... 46Pickles, C ........................................................ 23Piercey, S ......................................................... 48Pignatari, L ...................................................... 16Pihlasalo, J ...................................................... 46Pilgrim, L ........................................................ 48Pineda-Rivera, M ............................................ 23Pitard, F ........................................................... 16Pleysier, R ....................................................... 49Poirier, S ............................................................ 2Portillo, G ........................................................ 30Poulin, S .......................................................... 12Prakash Narayan, S ......................................... 20Prasad Rao, K .................................................. 19Pratt, A............................................................. 13Prazeres, E ....................................................... 41Prengaman, R .................................................... 4Provis, J ........................................................... 49

Q

Quintela, M ..................................................... 11

R

Rashchi, F ................................................. 11, 33Ratvik, A ........................................................... 8Ravindran, C ................................................... 19Reinhardt, J ..................................................... 14Rezaei Farkoosh, A ......................................... 20Riad, K ............................................................ 20Richards, N ..................................................... 21Rimaszeki, G ................................................... 11Robben, M....................................................... 42Robertson, J..................................................... 25Robinson, T ..................................................... 15Rodriguez-Rodriguez, C ................................. 37Rogge, R ......................................................... 19Romero-Serrano, A ......................................... 23Rørvik, S ........................................................... 8Roy, R ............................................................. 40Runkel, M. ...................................................... 15

S

Saavedra, I ....................................................... 24Sadri, A ...................................................... 10, 45Saha-Chaudhury, N ......................................... 23Sahajwalla, V ............................................ 23, 40Sahoo, M ......................................................... 27Samtani, A ....................................................... 10Samue, A ......................................................... 28samuel, A ......................................................... 18Samuel, F .................................................. 18, 28Santos, R ......................................................... 23Sarvinis, J .......................................................... 4Schneeberger, G ........................................ 12, 39Schneller, M ...................................................... 7Scholey, K ....................................................... 22Schonewille, R ............................................ 3, 45Sediako, D ................................................. 18, 19Seetharaman, S ................................................ 31Seyed Ahmadi, M ............................................ 28Shankar, S ....................................................... 44Shariff, T ........................................................... 3Sheehan, G ........................................................ 4Shestak, Y........................................................ 11Shibata, E ........................................................ 32Shibayama, A ............................................ 32, 33Shiratori, T ...................................................... 32Sigler, D .......................................................... 21Simard, J ......................................................... 37Simon, J............................................................. 2Simons, A ........................................................ 46Sims, J ............................................................. 35Skidmore, C .................................................... 23Skybakmoen, E ................................................. 8Sokhanvaran, S ................................................. 2Solheim, A ......................................................... 8Somasundaram, P ............................................ 22Somasundaran, P ............................................. 22Songmene, V ................................. 18, 20, 27, 28Soucy, G ............................................................ 8Sridhar, R ........................................................ 40Staunton, B ........................................................ 5Staunton, W ............................................... 25, 49Steinlechner, S .......................................... 12, 39Støre, A .............................................................. 8

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Stubina, N ..................................... 15, 21, 31, 46Stubley, M ...................................................... 34Sudbury, M ...................................................... 29Sudbury, M .................................................. 4, 11Sugawara, K .................................................... 33SUGAWARA, K ............................................. 32Sukhram, M..................................................... 27Sunyer, A ......................................................... 12Su, T ................................................................ 27Syarifuddin, J .................................................. 10Sylvester, P ................................................ 48, 49

T

Tacher, M ........................................................ 38Tahan, A .......................................................... 28Takasaki, Y ...................................................... 33TAKASAKI, Y ................................................ 32Tangen, M ....................................................... 43Taylor, M ......................................................... 27Tebib, M .......................................................... 28Teng, L ............................................................ 31Thibodeau, S ..................................................... 7Thomas, K ....................................................... 31Thomas, S ......................................................... 2Thompson, P ................................................... 34Tian, Q ............................................................ 39Tikhonov, A ..................................................... 11Tjahyono, N ...................................................... 2Tohn, A .............................................................. 3Tokoro, C ........................................................ 32TONGAMP, W ................................................ 32Tonkin, C ......................................................... 16Torigoe, K ....................................................... 32Torrealba, J ...................................................... 16Torstein, U ....................................................... 38Tougas, B ........................................................ 19Townsend, R ................................................... 41Tripathi, N ....................................................... 45Tschöpe, K ........................................................ 8Tsunazawa, Y .................................................. 32Turek, C ............................................................ 6Twigge-Molecey, C ........................................... 2

U

Uken, R ........................................................... 14Upton, B .......................................................... 24Uribe-Salas, A ................................................. 37Usmar, S .......................................................... 29

V

Vahed, A .......................................................... 31Valle, N ........................................................... 14van der Merwe, W ........................................... 47van Deventer, J ................................................ 50van Eldert, J .................................................... 42Van Gerven, T ................................................. 23van Hille, R ............................................... 12, 13van Huyssteen, J ................................................ 6Van Weert, G ................................................... 50van Zyl, A ........................................................ 12Vasudevan, M .................................................. 22Vatansever, R .................................................. 28Vaughan, J ....................................................... 49Vega, M ............................................................. 5Vegter, N ......................................................... 40Vekris, E .......................................................... 21Verburg, R ....................................................... 25Vermette, H ..................................................... 27Verreman, Y .............................................. 18, 20Vidal, G ........................................................... 10Voermann, N ............................................... 4, 29Voicu, G .......................................................... 13

W

wanjara, P .......................................................... 3Wanjara, P ..................................................... 3, 8Warczok, A ...................................................... 38Warner, J ......................................................... 13Warner, T ......................................................... 29Wasmund, B ...................................................... 4Waters, K ......................................................... 30Weck, A ..................................................... 22, 30Welyhorsky, R ................................................. 16Westin, B ......................................................... 13

Wiechmann, E ................................................. 10Wijayaratne, H ................................................ 27Wilding, J ........................................................ 11Wilkinson, B ................................................... 41Wilkomirsky, I................................................. 24Williams, B ..................................................... 24Wong, D ............................................................ 2Wotruba, H ...................................................... 42Wu, P ............................................................... 23Wyethe, J ......................................................... 40

X

Xu, M ........................................................ 22, 23

Y

Yalcin, E .......................................................... 33Yang, Q ........................................................... 23Yang, S ............................................................ 23Yang, Y ............................................................ 23Yan, L .............................................................. 15Yasser, Z .......................................................... 18Ying, W ..................................................... 10, 45Yuan, D ........................................................... 15Yumoto, T ........................................................ 32

Z

zaharia, M ....................................................... 23Zaror, C ............................................................. 5Zedan, Y .................................................... 18, 28Zeifert, B ......................................................... 23Zhang, G ......................................................... 23Zhang, S .......................................................... 25Zhang, Y ............................................................ 8Zhou, J......................................................... 5, 14Ziegler, D ...................................................... 7, 8Zinck, J ...................................................... 11, 39

AM PM AM PM AM PM

PlenaryWestmount / Outremont

Plenary I Start: 8:30 - p. 2

Plenary II Start: 8:30 - p. 17

Keynote I Start: 10:00 - p. 5

Plenary - Round table Discussion

Start: 14:00 - p. 14

Keynote II Start: 8:55 - p. 41

Mineralogy of Precious Metals I

Start: 10:50 - p. 5

Mineralogy of Precious Metals II

Start: 15:15 - p. 14

Gravity Recovery Start: 9:30 - p. 25

Non Cyanide Lixiviants Start: 14:00 - p. 36

New Concepts I Start: 9:45 - p. 42

Fundamentals Start: 14:00 - p. 45

Fontaine D Strategic Mine Planning I Start: 10:50 - p. 6

Strategic Mine Planning II Start: 15:15 - p. 16

Environment Start: 9:30 - p. 24

Geology II Start: 14:00 - p. 34

Mining-Maintenance and Engineering

Start: 9:45 - p. 41

Geology III Start: 14:00 - p. 47

Fontaine E Geology I Start: 15:15 - p. 13

Management and Mineral Economics -

Start: 14:00 - p. 36

Mining III Start: 9:45 - p. 42

Lachine Aluminium Production I Start: 10:00 - p.2

Aluminium Production II Start: 14:00 - p.7

Light Metals Ti and Mg Start: 9:30 - p. 19

Aluminium Production III

Start: 14:00 - p. 26

Aluminium Transformation III Start: 8:30 - p. 37

Aluminium Transformation IV Start: 14:00 - p. 44

LasalleAluminium

Transformation I Start: 9:30 - p. 18

Aluminium Transformation II Start: 14:00 - p. 27

Le Portage REGAL Start: 8:10 - p. 20

New Technology Implementation Fontaine H New Technology Review

Start: 10:00 - p. 3

New Technology Implementation

Start: 14:00 - p. 10

Industry-University Interaction

Start: 9:30 - p. 22

Scale Up Start: 13:35 - p. 30

Energy Start: 8:55 - p. 38

Modelling Start: 13:35 - p. 45

Verdun Metal Recycling I Start: 10:00 - p. 4

Remediation. Characterization Start: 14:00 - p. 11

Metallurgical Slag, Dust Start: 9:30 - p. 23

Advances from Japan. Precious Metals

Start: 13:35 - p. 32

By-products Processing Effluents, Wastewater

Treatment Start: 8:30 - p. 39

Lasalle Metal Recycling II Start: 14:00 - p. 11

Innovation in Joining Advanced Materials (IJAM II)

LongueuilLaser Welding and

Processing Start: 10:00 - p. 3

Welding Proc. Involving Hot Deformation / Arc Welding

Processes Start: 14:00 - p. 8

Understanding Innovations

Start: 9:30 - p. 21

MicroWelding Processes

Start: 14:00 - p. 30

Management Fontaine G Management I Start: 9:30 - p. 21

Management II Start: 14:00 - p. 29

WEDNESDAY, OCTOBER 5

Technological Developments / Cyanide

Start: 9:30 - p. 25

Comminution/ Concentration

Start: 14:00 - p. 33

TUESDAY, OCTOBER 4

Technical Program @ a GlanceMONDAY, OCTOBER 3

Refractory Ores Start: 15:15 - p. 15Mont-Royal

SYMPOSIUM Room

World GoldPlant Practice &

Projects I Start: 10:50 - p. 6

Pregrobbing / Recovery

Start: 14:00 - p. 47

New Concepts II Start: 9:45 - p. 43

Hampstead / Cote St. Luc

Poster Sessions Poster SessionsPoster Sessions Poster SessionsPoster Sessions Fontaine A Poster Sessions

Waste Processing &

Recycling

Light Metals