KP-2012-CO41-0457-T

Hudbay Peru S.A.C. Gravity Flow Floating Decant System

(Barge) Performance Criteria

August 22, 2012

prepared for: Hudbay Perú S.A.C.

Av. El Derby No. 055, Torre 3, Piso 4 Distrito de Santiago de Surco

Provincia y Departamento de Lima Perú

prepared by:

Knight Piésold and Co.

1999 Broadway, Suite 600 Denver, Colorado 80202-5706 USA

Telephone: (303) 629-8788 Facsimile: (303) 629-8789

E-mail: [email protected]

KP Project No. DV201.00245/41

Rev. No. Date Description Knight Piésold Client

A August 22, 2012 For review and comment Gilberto Domínguez Terry Linde

Gravity Flow Floating Decant System (Barge) Performance Criteria, Rev A

i



Table of Contents

Page

PART 1.0 - GENERAL ............................................................................................ 1-1

1.1 SCOPE .................................................................................................................................... 1-1

1.2 REFERENCES ........................................................................................................................ 1-2

1.3 GENERAL REQUIREMENTS ................................................................................................. 1-2

1.4 DOCUMENTATION ................................................................................................................ 1-3

1.5 QUALITY ASSURANCE ......................................................................................................... 1-3

1.6 DELIVERY, STORAGE, AND WARRANTY ........................................................................... 1-4

PART 2.0 - PRODUCTS ......................................................................................... 2-1

2.1 TECHNICAL REQUIREMENTS .............................................................................................. 2-1

2.2 INSPECTION AND TESTING ................................................................................................. 2-2

2.3 PAINTING ............................................................................................................................... 2-2

Figures Figure 1 General Arrangement Plan Figure 2 Embankment Section and Details Figure 3 Pond Section and Embankment Profile Figure 4 Outletworks Plan, Profile, and Details M:\Denver\Projects\201\00245.41\Deliverables\Reports Specs\1300 Sediment Ponds\MainSedPond\BargePerformanceCriteria\RevA\Text\Text_RevA.docx


1-1



PART 1.0 - GENERAL

Project: Constancia Mine Location: Southern Peru – Cusco Average Site Temperature: -0.4 ˚C to 15.3 ˚C Project Lifespan: 15 years Owner: Hudbay Peru S.A.C. Contractor: Stracon - GYM Consulting Engineer: Knight Piésold – Attn: David Branz

1.1 SCOPE

A. Scope of Services

Performance requirements for designing, manufacturing, transporting, installation supervision and commissioning a single floating decant system (barge) at the Main Sediment Pond (Pond) of the Constancia Project. The barge shall drain the Pond of site runoff water by gravity, adhering to the requirements listed below. No pumps or valves are required for operating the barge.

B. General Overview The following items include site conditions and barge requirements. Further details can be found in Part 2 of this document:

• Floating barge designed to discharge the flows listed in Section 1.3.

• Flexible outflow pipe (hose) from the barge to a fixed HDPE outlet pipe in the dam designed to discharge the flows listed in Section 1.3. Supplier is responsible for ensuring that the full outlet works meets the discharge requirements, and that the hose remains within its specific performance specifications.

• Weighted or floating pipe collars on the hose as needed to alleviate stresses and movement of hose.

• Structural anchors attached to winches mounted to the barge by cables tying the barge to the pond shore and/or bottom. The purpose of the winch and anchor system is to allow operators to control the range of horizontal and vertical movement of the barge. Controlling the vertical range of movement of the barge from the maximum and minimum elevations listed in the table in section 1.3 and the horizontal range of motion will allow for proper functioning of the barge while minimizing stresses on the flexible hose and pipefittings.

• An access road and docking pad shall be provided at the bottom edge of the pond adjacent to the barge. Through use of the winch and anchor system, the operators may dock the barge for maintenance and while it is not in use during the low water condition.

• Stand or structure attached to the bottom of the barge that allows the barge to rest on the ground without damaging the barge and discharge system or clogging the inlet with mud.


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• Turbidity meter mounted on the barge to measure solids concentration in the discharged water. The operator shall rely on the turbidity meter to determine if the water near the barge inlet meets the water quality requirements shown in Section 1.3. Based on the turbidity readings, the operator shall be able to control the discharge of the barge by opening or closing valves installed at each end of the HDPE outlet pipe that runs through the embankment. Valves, turbidity meter, and HDPE outlet pipe are included in a separate scope of services.

• The barge shall be accessed during operation and while floating in the pond by a small boat, i.e., dinghy that can be docked on the shore while not in use.

1.2 REFERENCES

A. Codes and Standards

The equipment shall comply with the requirements of this performance specification, with applicable Specifications, Codes, Standards, stated below. The latest edition at time of award shall apply:

• AISI American Iron and Steel Institute.

• ANSI American National Standards Institute.

• B1.20.1 Pipe Threads

• B16.5 Pipe Flanges and Fittings (Steel)

• ASTM American Society of Testing and Materials

• API American Petroleum Institute

• PPI Plastics Pipe Institute

• ASTM American Society for Testing and Materials

• AWWA American Water Works Association

1.3 GENERAL REQUIREMENTS

• The design, materials, and construction shall be new and in accordance with the Supplier's standard practice or recommendation for the intended service unless the requirements listed in this specification preclude their use.

• The Supplier shall guarantee that the equipment will perform satisfactorily for the capacities and design conditions stated in this specification.

• If special tools are required for assembly and maintenance, they shall be furnished.

• Design discharge flow rate at maximum head for barge = 75,000 m3/day

• Required Total Solutions in Suspension (TSS) of discharged water = 50 ppm

• Depth of surface water to be skimmed = 500 mm

• pH range of pond water = 6-9

• Pond live storage capacity (between elevations 3986.0 and 3995.0 masl) = 840,000 m3

• Pond dead storage capacity (between elevations 3983.0 and 3986.0 masl) = 95,000 m3

• The water in the pond is expected to be low for half of the year during the dry season and intermittently fill and empty as storms and drawdown dictate during the rainy season the other half of the year.

• The general barge location is shown on the attached drawings. The barge should be located near the left abutment (to be verified prior to final barge design) and allowed to float to the levels shown in the table below. The expected maximum change in water


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elevations in the pond during normal operations is 8.5 m. The elevation of the barge shall be synonymous with the skimming elevation.

• Critical Elevations are listed in the following table.

Main Sediment Pond

Description Elevation (masl)* Embankment crest elevation 3997.0 Maximum operating water surface elevation 3995.0 Minimum water surface elevation 3986.0 Pond bottom at the location of the barge 3983.5 Maximum skimming elevation (0.5 m below maximum operating water surface elevation)

3994.5

Minimum skimming elevation (at minimum live storage elevation)

3986.0

*All elevations to be verified prior to final barge design

1.4 DOCUMENTATION

The Supplier shall supply the following items with their bid:

• All drawings and data listed in accordance with the requirements shown in Section 1.3.

• A list of spare parts which will be required for reliable operation of the equipment for 1-year operation.

• A list of any exceptions to this specification with the bid. The Supplier shall be responsible for completeness of exceptions taken. If no exceptions are listed it will be assumed that specification as written shall be met completely.

• Calculations for barge stability, buoyancy and discharge hydraulics based on the operating conditions of the barge and discharge.

• Technical and operational characteristics of the offered barge. The minimum information shall be the hydraulics, dimensions, erection details, and materials of construction. The load capacity of the offered barge shall be included.

• Maintenance schedule and procedures.

1.5 QUALITY ASSURANCE

A. General

• The Supplier shall be solely and entirely responsible for the process performance of the equipment and systems. The Supplier shall guarantee that the equipment(s) will operate satisfactorily to the conditions and requirements of this specification and datasheet.

• The Buyer reserves the right to witness any tests or inspections, which considers necessary to ensure that components conform to Quality Assurance requirements. Supplier shall notify Buyer in advance of all tests and grant free access to manufacturing facilities, including those of his sub-suppliers, for such inspections.

• The Supplier shall provide the Buyer with the complete list of documentation for review. Such documents shall cover manufacturing, quality control, inspection procedures, deficiency evaluation, and correction.

• All inspection reports shall be made available for inspection by the Buyer.

• All defects in excess of agreed acceptance criteria shall be reported immediately to the Buyer by the Supplier and evaluated by the Supplier’s engineering departments for possible corrective action. All corrections shall be subject to the Buyer's approval.


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• The Supplier shall not substitute major component sub-suppliers after award of a Purchase Order without the Buyer’s approval.

• The Supplier shall assign an experienced project coordinator whose responsibility shall be to supervise all aspects of the work.

• The Supplier shall maintain a quality assurance program during the fabrication and assembly of equipment. All quality inspection records signed by the Quality Control Inspector shall be available for the Buyer's review.

• The Supplier shall maintain reliable services and make available required parts during installation and field-testing, and thereafter, during 1 year of operation.

1.6 DELIVERY, STORAGE, AND WARRANTY

• Commissioning services shall take place on site during early November 2012.

• The Supplier shall provide in its bid a schedule to deliver a design package, shipment of components, and installation of barge from the date of notice to proceed.

• The warranty period for all components shall be 12 months from startup or 18 months from shipment, whichever occurs first.


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PART 2.0 - PRODUCTS

2.1 TECHNICAL REQUIREMENTS

A. Gravity Flow Floating Decant System (Barge)

• Barge and equipment shall be complete and operable and shall meet the requirements described above.

• The Supplier shall accept full responsibility for the complete design and materials of construction for the barge.

• The offered barge shall be based on a proven design.

• The assembled barge shall have lugs to lift the barge as a unit, without damage; this lifting operation does not include the flexible hose.

• Each barge shall be equipped with bolted safety hand railing with a single man opening for access.

• Gratings shall have anti-skid surface.

• The invert elevation of the HDPE outlet pipe that the flexible hose from the barge connects to is not finalized. The Supplier shall provide the recommended invert elevation for this pipe.

• The Supplier shall provide the elevation required for the pond bottom in the vicinity of the barge based on barge dimensions and operating conditions.

B. FLEXIBLE HOSE

The Supplier shall provide the flexible hose that attaches the barge inlet to the provided outlet pipe flange. The hose shall be designed to convey the required discharge flow shown in Section 1.3 and to withstand normal operating wear and tear for the life of the project.

C. PIPE CONNECTIONS The Supplier shall provide proper pipefittings and connections associated with the barge and at the end of the flexible hose where it connects to the HDPE outlet pipe.

D. STRUCTURAL ANCHORS The Supplier shall provide exact location of anchors that will allow for optimum operation of the barge. Anchor design is not required; however, recommendations and design input are to be provided to allow for proper anchor design.

E. WINCHES The Supplier shall provide and install winches on the barge that meet the load requirements for controlling barge movement horizontally and vertically for the life of the project.

F. CABLES The Supplier shall provide the cables that connect the winches on the barge to the anchors. The cables shall be in compliance with the proper standards and shall allow for the proper operation of the barge throughout the life of the project.


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G. STAND The Supplier shall provide a stand or structure attached to the bottom of the barge that allows the barge to rest on the ground without damaging the barge and discharge system or clogging the inlet with mud.

H. INSTRUMENTATION The Supplier shall provide recommendations for mounting a turbidity meter to the barge.

I. MAINTENANCE The Supplier shall provide operation and maintenance procedures for the barge. Maintenance is expected to be performed while floating in the pond when possible; otherwise, maintenance shall be performed while docked on shore. A crane may be employed if necessary to raise the barge off the ground or water surface.

2.2 INSPECTION AND TESTING

• The Buyer reserves the right to witness any tests or inspections which he considers necessary to ensure that components conform to Quality Assurance requirements. Supplier shall afford free access to manufacturing facilities, including those of his sub-suppliers for such inspections.

• All defects in excess of agreed acceptance criteria shall be reported immediately to the Buyer by the Supplier and evaluated by Supplier’s engineering departments for possible corrective action. All corrections shall be subject to Buyer’s approval.

2.3 PAINTING

• Barge shall be painted according the Supplier’s standard. The Supplier shall inform in their bid the detail of offered paint system. Corrosion resistant paint shall be applied to metal parts on the barge and floating elements shall be able to withstand the expected conditions.

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KP-2012-CO41-0457-T

Documents

dbranz drawing path

hdpe outlet pipe

agreed acceptance criteria

suppliers engineering departments

quality assurance requirements

final barge design

anchor system

turbidity meter