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Martinick Bosch Sell Pty Ltd 4 Cook Street West Perth WA 6005 Ph: (08) 9226 3166 Fax: (08) 9226 3177 Email: [email protected] Web www.mbsenvironmental.com.au
PREPARED BY:
KIDMAN RESOURCES LIMITED
DECEMBER 2017
EARL GREY LITHIUM PROJECT PROCESS TAILINGS GEOCHEMICAL ASSESSMENT
EARL GREY LITHIUM PROJECT PROCESS TAILINGS GEOCHEMICAL ASSESSMENT
Distribution List:
Company Contact Name and Position Copies Date
Kidman Resources Limited Chris Williams, General Manager 1 8 December 2017
Document Control for Job Number: KRLEGGC
Document Status Prepared By Authorised By Date
Draft Report Dave Allen and Michael North Kristy Sell 8 December 2017
Final Report Dave Allen and Michael North Kristy Sell 20 December 2017
Disclaimer, Confidentiality and Copyright Statement This report is copyright. Ownership of the copyright remains with Martinick Bosch Sell Pty Ltd (MBS Environmental). This report has been prepared for Kidman Resources Limited on the basis of instructions and information provided by Kidman Resources Limited and therefore may be subject to qualifications which are not expressed. No other person other than those authorised in the distribution list may use or rely on this report without confirmation in writing from MBS Environmental. MBS Environmental has no liability to any other person who acts or relies upon any information contained in this report without confirmation. This report has been checked and released for transmittal to Kidman Resources Limited. These Technical Reports:
Enjoy copyright protection and the copyright vests in Martinick Bosch Sell Pty Ltd (MBS Environmental) and Kidman Resources Limited unless otherwise agreed in writing.
May not be reproduced or transmitted in any form or by any means whatsoever to any person without the written permission of the Copyright holder.
TABLE OF CONTENTS 1. INTRODUCTION ........................................................................................................................................... 1
1.1 PROJECT BACKGROUND ............................................................................................................................. 1 1.2 OBJECTIVE AND SCOPE OF WORK ............................................................................................................... 1
2. PROCESS OVERVIEW .................................................................................................................................. 3
The Earl Grey Lithium Project (the project) is located approximately 105 km south southeast of Southern Cross, Western Australia. A large, economic pegmatite-hosted lithium deposit was discovered by Kidman Resources Limited (Kidman) in 2016. The deposit and proposed operation is situated at the abandoned Mt Holland Gold Mine, which operated between 1988 and 2001, and comprises a number of open pits, an underground mine, a processing plant, waste rock dumps, tailings storage facilities (TSFs) and other infrastructure that is largely unrehabilitated and currently a liability of the State of Western Australia. The key components of the project will comprise:
Progressive mining of the Earl Grey lithium deposit using conventional open cut drill and blast mining methods, over a potential 30 to 40 year life of mine (LOM), with transfer of ore to a run of mine (ROM) pad in preparation for processing.
Processing of lithium ore (dominant lithium minerals being spodumene and petalite, which are both alumino silicates) at a rate of 3 million tonnes per annum, through a newly constructed gravity separation and flotation plant, largely constructed within the historic disturbance footprint.
Production of a spodumene based lithium concentrate that will be stored in a concentrate shed prior to being transported offsite for further processing to extract the lithium.
Production of two process waste streams, comprising:
A gravel sized coarse reject stream of primarily quartz and other benign minerals which will be disposed of in waste rock dumps as well as being used for construction purposes (e.g. road base, fill, rehabilitation armouring).
A finer grained tailings stream that will be deposited into either the abandoned and unrehabilitated Mt Holland Gold Mine TSF or an expansion to the existing in-pit TSF. No new TSF is planned as part of the project.
1.2 OBJECTIVE AND SCOPE OF WORK
The objective of the study was to determine the potential for acid and metalliferous drainage (AMD), neutral or saline drainage to occur from tailings and identify if disposal of the tailings materials poses any significant risks to the surrounding environment. Previous work by MBS had characterised the geochemical properties of the pegmatite ore from which the current tailings stream will be derived (MBS 2017a) and hence was also available as reference for the current work. The scope of work for process tailings geochemical assessment involved:
Liaison with Kidman for the collection and submission of a representative process sample to laboratories for the following analysis:
Acid base accounting (ABA) parameters including chromium reducible sulfur (CRS) and acid neutralising capacity (ANC).
Total metals and metalloids composition by X-Ray Fluorescence (XRF) spectrometry.
Water leachate using a 1:5 extraction ratio for pH and electrical conductivity (EC).
Leaching Environmental Assessment Framework (LEAF) Test Method 1313 (pH dependence, US EPA SW-846 method).
Prepare a report outlining relevant geochemical properties, including the potential for acid formation and saline and neutral leaching of environmentally significant metals and/or metalloids to the surrounding environment.
2. PROCESS OVERVIEW The Earl Grey deposit is proposed to be mined via conventional open cut methods. The pit is planned to be developed in multiple stages over a 30 to 40 year period, with the first stage providing ore for years 1 to 6. Approximately 100 million tonnes of ore will be mined over the life of mine. Development of the pit will be undertaken using conventional drilling and blasting methods in 5 m benches, with broken material excavated on 2.5 m horizontal flitches. Ore will be transported to a ROM pad for transfer to the processing plant. Low grade ore will be transported to a separate stockpile located to the immediate southeast of the pit. Processing of ore to produce a spodumene concentrate will occur in stages as follows:
Crushing: The processing circuit requires lithium ore to be crushed. This will be undertaken by feeding ore from the ROM in to a three-stage crushing circuit comprising of a primary jaw crusher, a dry triple deck sizing screen, secondary and tertiary crushers and fine ore storage bin at a design throughput of 3 Mtpa, producing 3.35 mm crushed ore.
Removal of fines (desliming) and iron: Very fine material (slimes) will be removed in a cyclone. The deslimed ore is then crushed to a P80 size off 0.18 mm and iron minerals separated magnetically.
Flotation: Spodumene (and some petalite refer glossary, Section 7) is concentrated by flotation using oleic acid (2,500 g/t) adjusted to pH 8 using soda ash (sodium carbonate) and sodium silicate (70 g/t).
The final spodumene concentrate product will be stored in a purpose built storage facility immediately adjacent to the processing plant, prior to transport offsite either for export to overseas markets or for lithium extraction within Western Australia. Over the life of mine, approximately 10 Mt (7,500,000 m3) of fine tailings and 70 Mt (33,000,000 m3) of coarse gravel rejects are expected to be produced. Gravel rejects will be managed as fresh waste rock or used as a construction material (e.g. road aggregate). Fine tailings will be deposited into either the abandoned and unrehabilitated Mt Holland Gold Mine Tailings Storage Facility (TSF) or an expansion to the existing in-pit TSF.
There is no simple method to define whether mine waste containing small quantities of sulfur will produce sulfuric acid. Sulfide minerals are variable in their behaviour under oxidising conditions and not all forms will produce sulfuric acid (H2SO4). Instead, a combination of approaches is often applied to more accurately classify mine waste. These approaches are listed below in order of increasing data requirements (and therefore increased reliability):
The “Analysis Concept”, which only requires data for total sulfur content. Its adoption is based on long term experience of hard rock wastes from Western Australian mine sites in arid and semi-arid conditions. Experience has shown that waste rock containing very low sulfur contents (0.3%) rarely produces significant amounts of acidic seepage.
The “Ratio Concept”, which compares the relative proportions of acid neutralising minerals (measured by the ANC) to acid generating minerals (measured by the Acid Production Potential (AP)). Experience has shown that the risk of generating acidic seepage is generally low when this ratio (the Neutralisation Potential Ratio – NPR) is above a value of two.
Acid-Base Accounting, in which the calculated value for Nett Acid Producing Potential (NAPP) is used to classify the acid generating potential of mine waste. NAPP is equal to the AP minus the ANC.
Procedures recommended by AMIRA (2002), which take into consideration measured values provided by the NAG test and calculated NAPP values.
Kinetic leaching column test data, which provides information for the relative rates of acid generation under controlled laboratory conditions, intended to simulate those within a waste rock stockpile or tailings storage facility.
A sound knowledge of geological and geochemical processes must also be employed in the application of the above methods. ABA accounting methods are outlined in full in AMIRA (2002), DIIS (2016) and the ‘GARD’ guide (INAP 2009). Classification of wastes in this report is based on use of CRS to measure potentially acid generating sulfide minerals. The CRS method was preferred to the AMIRA method of indirect measurement of oxidisable sulfur as the difference between total sulfur and sulfate sulfate (measured by dilute acid extraction) based on the very low sulfur content of Earl Grey ore (MBS 2017a) and the expected contribution of acid insoluble sulfate minerals such as barite and celestite. AP was calculated by multiplying the CRS concentration (% S) by 30.6 (kg H2SO4/t). ANC was measured, allowing NAPP and NPR to be calculated.
3.2 LABORATORY METHODS
A composite sample of representative process tailings from separation of spodumene and petalite from pegmatite ore was prepared by Nagrom (Kelmscott, Perth, WA). Three sub-samples of this material were submitted to MPL Envirolab laboratories (Myaree, Perth WA) for further analysis on 9 November 2017. An additional five samples were submitted on 11 December 2017 (Section 4.1). Methods of analysis for this study are indicated in the following sections. Results are collated in Appendix 1 and laboratory reports are provided in Appendix 2 and Appendix 3.
3.2.1 Acid Base Accounting
Sample analysis was performed by MPL Envirolab laboratory. CRS was measured by the method of Ahern et al. (2004). ANC was measured using the Sobek method (AMIRA 2002). pH of a slurry following reaction with
hydrogen peroxide (pHFOX) was measured as an indication of the potential for acid generation by oxidation of sulfide minerals. The samples were also tested for pH and EC on a 1:5 sample:water extract.
3.2.2 Elemental Composition
Elemental composition of ore and tailings was also performed by Nagrom Minerals using XRF for the elements Al, Ca, Fe, K, Mg, Mn, Na, Nb, P, Pb, Rb, Sn, Si, Ta and Ti. This is a total determination for the elements measured. Data for earlier analysis of five samples of lithium ore included in the waste rock characterisation program (MBS 2017a) were also included in this assessment. Major and trace metals/metalloids were measured following digestion of a finely ground sample with a four acid mixture of nitric, hydrochloric, perchloric and hydrofluoric acids, which is a total determination for the elements measured. Digest solutions were analysed using inductively coupled plasma mass spectrometry (ICP-MS) or inductively coupled plasma optical emission spectrometry ICP-OES. The method is not suitable for accurate measurement of volatile elements such as mercury and boron. One sample of tailings (P1710052) was also assessed for metals and metalloids using a reverse aqua regia digestion which assesses metals which may be leachable under extreme conditions to the environment. This method is suitable for volatile elements. From the total four acid digestion or XRF data, the global abundance index (GAI) for each element was calculated by comparison to the average earth crustal abundance (Bowen 1979 and AIMM 2001). The main purpose of the GAI is to provide an indication of any elemental enrichment that could be of environmental significance. The GAI (based on a log-2 scale) is expressed in integer increments from zero to six (GARD Guide). A GAI of zero indicates that the content of the element is less than or up to three times the average crustal abundance; a GAI of one corresponds to a three to six fold enrichment; a GAI of two corresponds to a six to 12 fold enrichment and so forth, up to a GAI of six which corresponds to a 96-fold, or greater, enrichment above average crustal abundances. A GAI of more than three is considered significant and may warrant further investigation.
3.2.3 Leaching Environmental Assessment Framework Test Method 1313
The Leaching Environmental Assessment Framework (LEAF) is currently being evaluated for assessment of waste derived materials in Western Australia. The Department of Water and Environmental Regulation (DWER) advocates adoption of one of these tests (US EPA SW-846, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, Test Method 1313 (pH dependence) for characterisation of mining wastes. Test Method 1313 determines how liquid-solid partitioning varies with the pH of the leaching solution using a parallel batch extraction method. This test method applies a full range of pH conditions that the test material may be exposed to in the environment, thereby providing a high level of confidence in predicting the likely concentrations of contaminants in leachates from these materials in various settings. A composite sample was analysed by MPL Envirolab laboratories using Test Method 1313, which involves parallel batch extraction with nine solutions at a solid to liquid extraction ratio of 1:10, with final pH values between 2 and 13 pH units. Each filtered extract solution was analysed for 28 metals and metalloids by ICP, soluble sulfur by ICP and soluble fluoride using an Ion Specific Electrode (ISE) method. Dissolved Organic Carbon (DOC) was measured by an in-house automated colorimetric method. DOC concentrations provide an indication of residual concentrations of oleic acid used in the process (Section 2).
Five samples of tailings were initially provided by Nagrom for geochemical assessment. The samples were marked as follows:
T2345 test work comp sighter rougher tail composite.
Duplicate samples marked P17100151 post settlement and P17100151 post settlement Spare.
Duplicate samples marked P17100152 post settlement and P17100152 post settlement Spare. Three samples (T2345 and one of each duplicate sample marked P17100151 and P17100152) were initially submitted to MPL Envirolab laboratory for analysis on 9 November 2017. The sample marked “P17100151 post settlement” was subsequently shown to be contaminated by sulfidic materials, which was attributed to previous geotechnical testing of the sample by an engineering laboratory and cross contamination with other samples. This contamination was clearly indicated by the presence of very elevated concentrations of iron (19,000 mg/kg), chromium (880 mg/kg), nickel (380 mg/kg), copper (140 mg/kg) and manganese (560 mg/kg) in sample P17100151 versus P17100152 (Appendix 2, Report 203076-C). The other samples (T2345 and duplicate samples of P17100152) are considered to be representative of project flotation tailings. Partially to confirm the anomalous, contaminated nature of P17100151 an additional five samples of tailings material were subsequently provided by Nagrom. These samples were submitted to MPL Envirolab laboratory for analysis of 11 December 2017. These samples were identified as follows:
Sighter Float Test 25 Ro Tail.
Sighter Float Test 26 Ro Tail.
Sighter Float Test 25RPT Ro Tail.
Sighter Float Test 27 Ro Tail.
Sighter Float Test 28 Ro Tail.
4.2 ACID M INE DRAINAGE CHARACTERISATION
Laboratory results for CRS and ANC and calculated ABA parameters (AP, NAPP and NPR) are collated in Table A1-1 of Appendix 1. Original laboratory reports are included in Appendix 2. The material was classified as NAF based on non detectable CRS concentrations (<0.005%) in all uncontaminated samples and is not expected to produce acidic seepage as a result of sulfide oxidation. The ANC values were also low, ranging from 2.4 to 4.3 kg H2SO4/t, which is consistent with the unreactive nature of the dominant minerals in the tailings such as quartz and feldspars. Some of the measured ANC is attributed to sodium silicate used in the process (Section 2). pHFOX values from artificial oxidation with hydrogen peroxide were slightly acidic, ranging from 5.0 to 5.6 on the uncontaminated samples. The difference between these values and the moderately alkaline pH values of 1:5 water leachates (Section 4.4) is attributed to carbon dioxide and/or organic acidity produced by complete or partial peroxide oxidation of residual oleic acid (Section 4.5.5).
Table A1-2 of Appendix 1 presents heavy metal and metalloid compositions for the tailings sample. Also included are elemental concentrations for the same elements measured in the sample of ore provided to Nagrom for the metallurgical program, and ranges of concentrations of these and other elements in six samples of ore-grade pegmatite included in the MBS waste rock characterisation report (MBS 2017a). Table A1-3 of Appendix 1 presents calculated GAI values for these samples, as outlined in Section 3.2.2. Examination of the total element concentrations and the corresponding GAI values for ore grade materials and process tailings indicated the following key points:
Significant enrichment (GAI value of three or more) in beryllium, rubidium, tin and tantalum in ore grade materials. These elements are all naturally elevated in pegmatite lithologies, but also normally present in highly insoluble forms. Lithium is also, as expected, significantly enriched.
Low concentrations of common rock forming elements calcium and magnesium, particularly in tailings, but close to global abundance concentrations of potassium (2.5% versus global abundance average of 2.1%) and elevated sodium (3.5% versus global abundance average of 2.3%) in tailings.
Very low concentrations of environmentally significant metals and metalloids including antimony, cadmium, copper, chromium, selenium, antimony, mercury, nickel, lead and zinc. Most concentrations in samples of both materials were close to or below the laboratory reporting limit.
No enrichment of radioactive elements uranium and thorium in ore grade materials. Radioactivity of naturally occurring rubidium, a low level β radiation emitter with a half-life of 49 billion years, has been discussed in an earlier MBS report (MBS 2017a) and is below levels requiring any specific management.
Comparison of elemental concentrations of ore and tailings samples analysed by Nagrom indicates:
Significant concentration of silicon, potassium and sodium in the tailings stream relative to the ore. These elements are associated with quartz and feldspars; the dominant rock-forming minerals in pegmatites which subsequently report to tailings.
Slight increase of rubidium concentration in tailings (2,450 and 2,820 mg/kg in ore and tailings, respectively). This observation suggests that rubidium is more associated with potassium minerals (by substitution for potassium in feldspar minerals) than lithium minerals in Earl Grey ore. This difference is consistent with differences in the elements with lithium ions being significantly smaller and lighter than potassium and rubidium ions.
As expected, lithium is significantly lower in tailings relative to the ore (0.72 and 0.095% in ore and tailings, respectively). The calculated tailings GAI value for 0.095% lithium (950 mg/kg) is 5, still indicating significant enrichment by comparison with the global average crustal abundance of 0.002% (20 mg/kg).
Significant depletion of iron, calcium, magnesium, titanium, manganese, phosphorus, tin, lead, tantalum and niobium in the tailings stream. This indicates these elements primarily report with floated spodumene/petalite to the concentrate.
4.4 WATER LEACHATE CHARACTERISATION
Results for pH and EC in the 1:5 water extract are given in Table A1-4 of Appendix 1. The sample leachates were found to be:
Slightly to moderately alkaline pH (ranging between 7.9 and 9.9 pH units for uncontaminated samples). These values are slightly less than those of Earl Grey pegmatite ore, for which pH values ranged from 9.2 to 9.8 pH units (MBS 2017a). As indicated in Section 2, the oleic acid flotation solution is buffered to pH 8 by addition of soda ash and sodium silicate, which accounts for the observed difference.
Non-saline, as indicated by very low EC of 24 and 180 µS/cm for uncontaminated samples (seven of eight samples being less than 70 µS/cm). Nagrom advised that Perth tap water was used for the metallurgical program and therefore may not reflect tailings produced by a processing plant at the project.
Overall, results suggest that tailings seepage will be slightly alkaline. The salinity of tailings from the project will reflect the final salinity of process water used with no appreciable soluble salts present in the material itself. Previous data (MBS 2017a), indicates hypersaline groundwater at the project of between 70,000 mg/L and 120,000 mg/L total dissolved solids.
4.5 LEACHING ENVIRONMENTAL ASSESSMENT FRAMEWORK TEST
METHOD 1313
Results for soluble metals, metalloids, fluoride and DOC in the pH dependent extracts of the T2345 Composite tailings sample by US EPA SW-846 Test Method 1313 (pH dependence) are presented in Appendix 3 in tabular and chart formats. ANZECC 2000 livestock drinking water quality guidelines, where available, have been included in the relevant charts as a comparator. It should be noted that, the receiving groundwater of between 70,000 mg/L and 120,000 mg/L total dissolved solids (MBS 2017a) is significantly more saline than is suitable for livestock (range 2,000 to 10,000 mg/L tolerable depending on species). In the absence of a livestock guideline for lithium, the ANZECC 2000 irrigation water quality guideline (2.5 mg/L) was used as the comparator. Final solution pH values ranged from 2.1 to 13. A leachate solution was also provided at “natural pH” of the sample, i.e. the leachate provided by use of deionised water as the leaching fluid without pH adjustment by addition of alkali or acid. The “natural pH” provided by this method was 7.9, which is slightly lower than the values of 8.9 and 8.7 pH units from analysis of 1:5 water extracts (Section 4.4). The lower pH was attributed to the different extraction ratio (1:10) and longer extraction time (24 hours, compared to one hour for the 1:5 water extract method). A summary of results for the LEAF test as grouped by analyte into four classes is summarised in Table 1. Results by class and for each particular element are discussed in Sections 4.5.1 to 4.5.4. Note that Table 1 indicates only changes in relative solubility with pH under the conditions of testing not net risk of soluble metals to the environment.
Table 1: Summary of LEAF Test Resul ts by Element
Group/Class Definition Elements in Class for Tailings
Material
Class 1
Insoluble/unreactive.
Class 1 analytes are present at very low or non-detectable concentrations at all pH values
Hg, Mo, Se, Th, V
Class 2
Acid soluble/reactive
Class 2 analytes are present at low to very low concentrations at circum-neutral and alkaline conditions but become increasingly soluble under acidic conditions. Many metallic elements such as calcium and magnesium are Class 2.
Ca, Mg, Cd, Co, Li, Mn, Ni, Sr, Tl, F
Class 3
Alkali soluble/reactive
Class 3 analytes are present at low to very low concentrations at circum-neutral and acidic conditions, but become increasingly soluble under alkaline conditions.
Sb, Sn, S/SO4
Class 4
Acid or Alkali soluble/reactive
Class 4 analytes are present at low to very low concentrations at circum-neutral pH, but become increasingly soluble under acidic and alkaline
Group/Class Definition Elements in Class for Tailings
Material
conditions. Amphoteric elements (for example aluminium and zinc) are Class 4 analytes.
4.5.1 Class 1 Elements
The following elements indicated Class 1 behaviour, were highly insoluble and therefore present no significant environmental risk:
Molybdenum, all concentrations at or below the laboratory reporting limit (0.001 mg/L).
Selenium, all concentrations less than 0.001 mg/L.
Thorium, all concentrations less than 0.0005 mg/L.
Mercury, all concentrations less than 0.00005 mg/L
4.5.2 Class 2 Elements
The following elements indicated indicated Class 2 behaviour. Apart from fluoride, most analytes were metals. It should be noted that given the absence of any acid forming minerals in the tailings, acidic conditions and any increased solubility which results is not expected for the project tailings as placed.
Fluoride. The maximum concentration was 0.5 mg/L in final pH 2 leachate. As the maximum concentration is well below the livestock drinking water guideline of 2 mg/L, fluoride presents no significant environmental risk.
Calcium and magnesium. The maximum concentrations were 19 and 7.3 mg/L, respectively, in final pH 2 leachate. These low concentrations indicate most of the calcium and magnesium is present as insoluble primary minerals.
Cadmium concentrations were below the laboratory reporting limit (<0.0001 mg/L) for leachates with pH between 5.5 and 13, and was only present in very low concentrations at low pH (maximum 0.001 mg/L at pH 2) compared to a livestock drinking water guideline (ANZECC 2000) of 0.01 mg/L.
Cobalt concentrations were below the laboratory reporting limit (<0.001 mg/L) for leachates with pH between 5.5 and 13, and was only present in very low concentrations at low pH (maximum 0.008 mg/L at pH 2).
Lithium concentrations were very low for leachates with pH between 5.5 and 13, ranging from 0.10 to 0.16 mg/L. Higher concentrations were recorded at low pH, with a maximum concentration of 2.6 mg/L in final pH 2 leachate. Although this maximum value is slightly higher than the ANZECC guideline value for lithium in irrigation water of 2.5 mg/L (ANZECC 2000), lithium in tailings leachate presents very low environmental risk.
Manganese concentrations were very low for leachates with pH between 5.5 and 13, ranging from 0.005 to 0.38 mg/L. Higher concentrations were recorded at low pH, with a maximum concentration of 3.9 mg/L in final pH 2 leachate. There is no livestock drinking water guideline for manganese (ANZECC 2000). The human drinking water guideline for manganese is 0.5 mg/L (DWER 2014), which is lower than the maximum observed manganese concentration. In addition, the human drinking water guideline for manganese is based on circum-neutral pH (i.e. 6.5 to 7.5) for which manganese concentrations were below 0.5 mg/L.
Nickel concentrations were very low for leachates with pH between 5.5 and 13, with a maximum of 0.001 mg/L. Higher concentrations were recorded at low pH, with a maximum concentration of 0.055 mg/L in final pH 2 leachate, however this still remained well below the livestock drinking water guideline of 1 mg/L.
Thallium results were below the laboratory reporting limit (<0.001 mg/L) for leachates with final pH values between 4 and 13. A maximum concentration of 0.002 mg/L was recorded for leachate with a final pH of 2.
4.5.3 Class 3 Elements
Antimony, tin and sulfur were the only elements with Class 3 behaviour. The maximum concentration of 0.002, 0.013 and 9.1, respectively, were recorded in leachate with final pH of 13. These concentrations indicate very low environmental risk for these elements. As noted for Class 2, the generation of such an extreme pH in as placed tailings (particularly given the process water buffering) is extremely unlikely and even these very low concentrations are not expected in as placed tailings.
4.5.4 Class 4 Elements
Several elements indicated Class 4 (amphoteric) behaviour:
Aluminium concentrations were variable, with the highest concentrations of 9.2 and 20 mg/L corresponding to final leachate pH values of 13 and 2, respectively. Much lower concentrations were recorded at pH values at or near the “natural pH” of 7.9. Concentrations in leachates with final pH values between 9 and 5.5 ranged from 0.25 mg/L (pH 9) to 0.05 mg/L (pH 5.5), well below the livestock drinking water guideline of 5 mg/L (ANZECC 2000). Aluminium is considered unlikely to present a significant environmental risk under the range of pH conditions expected within a TSF or co-disposal with Earl Grey waste rock (MBS 2017a).
Arsenic exhibited weak amphoteric behaviour, with the highest concentrations recorded in leachates with final pH values of 13 (0.11 mg/L), 12 (0.088 mg/L) and 2 (0.05 mg/L). All concentrations were well below the livestock drinking water guideline of 0.5 mg/L.
Beryllium concentrations were below the laboratory reporting limit (0.0005 mg/L) for leachates with final pH values between 5.5 and 12. Reportable concentrations were only noted for high pH leachates (0.001 mg/L at pH 13) and low pH leachate (0.0078 and 0.0026 mg/L at final pH values of 2 and 4, respectively. Beryllium is considered unlikely to present a significant environmental risk under the range of pH conditions expected within a TSF or co-disposal with Earl Grey waste rock (MBS 2017a).
Chromium concentrations were below the laboratory reporting limit (0.001 mg/L) for leachates with final pH values between 4 and 10.5. Reportable concentrations were only noted for high pH leachates (0.004 and 0.001 mg/L at pH 13 and 12, respectively) and low pH leachate (0.018 mg/L at pH 2). This behaviour indicates that chromium is only present in the trivalent form (chromium(III)), and not the more toxic hexavalent form (chromium(VI)). Concentrations were well below the livestock drinking water guideline of 1 mg/L for trivalent chromium (ANZECC 2000).
Copper concentrations were variable, with concentrations ranging from at or below 0.001 mg/L in the final leachate pH range of 5.5 to 9 (including the “natural pH”) to 0.29 mg/L at pH 2. Slightly elevated concentrations were reported at highly alkaline pH leachate values with a maximum of 0.021 mg/L at pH 13. All copper concentrations were well below the livestock drinking water guideline of 1 mg/L for (ANZECC 2000).
Iron concentrations were generally low, but variable. The highest concentrations of 5.2, 0.25 and 0.24 mg/L were recorded at final leachate pH values of 2, 3 and 13, respectively. Very low iron concentrations are predicted for leachate pH values between 5.5 and 10 and iron is considered highly unlikely to present a significant environmental risk under the range of pH conditions expected within a TSF or co-disposal with Earl Grey waste rock (MBS 2017a). Presence of low concentrations of iron at high pH (iron is not usually amphoteric) may be associated with complexation to oleate anions (Section 4.5.5).
Lead concentrations were below the laboratory reporting limit (0.001 mg/L) at leachates other than those with final pH values of 13 (0.005 mg/L) and 2 (0.095 mg/L). All concentrations were below the livestock drinking water guideline of 0.1 mg/L (ANZECC 2000).
Rubidium and caesium indicated similar amphoteric behaviour, although some rubidium in strongly alkaline leachates was attributed to contaminant levels in potassium hydroxide used for pH adjustment in the
laboratory. The highest rubidium concentrations of 0.54 and 0.33 mg/L were recorded in leachates with final pH values of 13 and 2, respectively. The highest caesium concentrations of 0.053 and 0.095 mg/L were also recorded in leachates with final pH values of 13 and 2 respectively.
Uranium exhibited weak amphoteric behaviour, with the highest concentrations recorded in leachates with final pH values of 13 (0.037 mg/L) and 2 (0.099 mg/L). All concentrations were well below the livestock drinking water guideline of 0.2 mg/L.
4.5.5 General Discussion
Concentrations of DOC did not align with these classes. The lowest concentration of 2 mg/L was recorded for leachates with final pH values between 2 and 7. The highest concentration of 5 mg/L was recorded for leachates with final pH values between 10 and 13. Concentrations of 4 mg/L were recorded for leachates with final pH of 7.9 (the “natural pH”) and 9. This behaviour indicates the oleate anion (the sodium salt of oleic acid which is generated under alkaline conditions) is less strongly bound to tailings solids than the free acid, which is the dominant form at acidic and circum-neutral pH values. The presence of low concentrations of oleic acid/oleate salts in slightly alkaline tailings seepage will contribute to a small biological oxygen demand (BOD). Although the predicted BOD is low (maximum 10.6 mg/L at “natural pH”) by comparison to other types of waste water, it may contribute to decreased redox potential of receiving waters in the environment and potential increases in concentrations of low valence elements such as iron, manganese and arsenic (as arsenite). Over time, the concentrations of biodegradable oleic acid and associated BOD are expected to decrease in response to expected biological mediated degradation within the TSF. The alkali metals lithium, rubidium, sodium and caesium exhibited similar behaviour to each other, exhibiting maximum solubility at very low (pH 2) and very high (pH 12 and 13) pH levels, with minimum solubility corresponding values slightly below the “natural pH” of the material (pH 7.9). The maximum concentration measured (2.6 mg/L) was for lithium at pH 2, which is slightly above the irrigation water guideline of 2.5 mg/L. There is very little toxicity data for rubidium and caesium. The alkali metal ions (Li+, Na+, K+, Rb+ and Cs+) are not considered toxic to most organisms at low concentrations as a consequence of their low reactivity to biologically active molecules by chelation or oxidation-reduction reactions. Of the alkali metal ions, lithium is considered the most reactive because of its higher charge density (high charge to ionic radius ratio). However, review of literature data (Aral and Vecchio-Sadus 2008, Shahzad et al. 2016) suggests that leachable concentrations of lithium (0.13 mg/L at “natural pH”) are unlikely to cause adverse environmental impacts. The United States Environmental Protection Agency (US EPA) has established regional screening levels (RSLs) for lithium which include industrial soil (2,300 mg/kg), residential soil (160 mg/kg) and residential soil in groundwater sensitive areas (12 mg/kg) (USEPA 2017). The soluble portion of lithium at “natural pH” of 0.13 mg/L represents 1.3 mg/kg in the solid material and is below all these soil criteria.
5. CONCLUSIONS AND IMPLICATIONS FOR MANAGEMENT Geochemical characterisation for two samples of process tailings from Earl Grey lithium ore has indicated this waste stream:
Is classified NAF due to an absence of detectable sulfides as CRS (<0.005%), and minor residual alkalinity; primarily from process water buffering. These concentrations, which are consistent with previous analysis of the pegmatite ore, are therefore considered insufficient based on the authors’ experience for any net acid production in Western Australian hard rock mines.
Is predicted to provide seepage that is moderately alkaline (pH 8 to 8.5) and non-saline (unless saline groundwater is used in the process plant) in the long term.
Is geochemically enriched in a number of elements including lithium, rubidium and possibly beryllium. Despite this enrichment, corresponding soluble concentrations of these elements and other metals and metalloids across a wide range of pH values were very low, indicating they are likely to remain in the solid form as insoluble minerals and do not pose a risk to (hypersaline) groundwater quality.
May initially produce seepage with some low levels of dissolved organic carbon, and hence BOD, as a consequence of dissolution of oleic acid used as the spodumene flotation agent in the processing plant. Concentrations of oleic acid and BOD, and decreased redox conditions, in tailings seepage are expected to decrease with time with microbial degradation.
One option being considered by Kidman for storage of process tailings is coverage of the eastern historic TSF at Mt Holland, which is currently uncovered and contains PAF gold tailings. This TSF is currently a State liability as oxidation of gold tailings is producing AMD (MBS 2017b). Coverage of these gold tailings with a thick layer of benign mine waste is expected to provide an effective barrier to ingress of air and water to the gold tailings and therefore provide an environmental benefit. MBS undertook a compatibility assessment between gold tailings and Earl Grey mine waste (waste rock and tailings) and concluded there was a very low risk of incompatibility (MBS 2017b). The report noted further assessment may be required if process chemicals, specifically high concentrations of fluoride, were used to produce lithium concentrates. The adopted process outlined only uses oleic acid and sodium silicate (Section 2) and concentrations of soluble fluoride in tailings examined were extremely low. Sodium silicate is considered environmentally benign as any residues in the tailings streams will slowly convert to alkaline sodium carbonate and insoluble silica. From the results of the US EPA SW-846 Test Method 1313 (pH dependence) LEAF test discussed in Section 4.5), there is no evidence that addition of oleic acid has resulted in dissolution of metals and metalloids in pegmatite ore at environmentally significant concentrations. As alkaline oleic acid solutions has no complexation capacity for divalent metals such as nickel, copper, lead and zinc, and metalloids including arsenic, selenium and antimony that are present at elevated concentrations in historic gold tailings (MBS 2017b), there is little considered risk of these metals being leached by lithium tailings seepage at concentrations higher than currently being leached by incident rainfall on an uncovered and slowly oxidising TSF. Overall, results indicate that Earl Grey lithium process tailings is considered geochemically benign, consisting predominantly of inert mineral forms (in particular quartz and feldspars) which are resistant to leaching and contain no potential for acid generation. Tailings seepage is predicted to be alkaline in perpetuity, non metalliferous, low and decreasing BOD from oleic acid residues and low concentrations of soluble fluoride. The salinity of tailings seepage will be determined by the salinity of process water used by the project, with minimal salinity arising from salts presence in Earl Grey ore or the flotation reagents.
6. REFERENCES Ahern, C.R., McElnea, A.E., Sullivan LA (2004). Acid Sulfate Soils Laboratory Methods Guidelines. In Queensland Acid Sulfate Soils Manual 2004. Department of Natural Resources, Mines and Energy, Indooroopilly, Queensland, Australia.
AIMM. 2001. Field Geologists’ Manual. Australasian Institute of Mining and Metallurgy Monograph 9. Fourth Edition. Carlton, Victoria.
AMIRA. 2002. ARD Test Handbook: Project 387A Prediction and Kinetic Control of Acid Mine Drainage. Australian Minerals Industry Research Association, Ian Wark Research Institute and Environmental Geochemistry International Pty Ltd, May 2002.
ANZECC. 2000. National Water Quality Management Strategy, Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand.
Aral, H. and Vecchio-Sadus, A. 2008. Toxicity of lithium to humans and the environment — A literature review. Ecotoxicology and Environmental Safety (70): 349 – 356.
Bowen, H.J.M. 1979. Environmental Chemistry of the Elements. Academic Press, London; New York.
DIIS. 2016. Preventing Acid and Metalliferous Drainage. Department of Industry, Innovation and Science, September 2016.
DWER. 2014. Assessment and Management of Contaminated Sites: Contaminated Sites Guidelines. Department of Water and Environment Regulation (DWER). Perth, Western Australia.
INAP. 2009. Global Acid Rock Drainage (GARD) Guide. International Network for Acid Prevention, www.gardguide.com (accessed 12 September 2017).
MBS 2017a. Earl Grey Lithium Project Waste Rock Characterisation. Report prepared by MBS Environmental for Kidman Resources Limited. May 2017.
MBS 2017b. Earl Grey Lithium Project Tailings Compatibility Assessment. Report prepared by MBS Environmental for Kidman Resources Limited. November 2017.
Shahzad, B., Tanveer, M., Hassan, W., Shah, A.N., Anjum, S.A., Cheema, S.A. and Ali I. 2016. Lithium toxicity in plants: reasons, mechanisms and remediation possibilities – A review. Plant Physiology and Biochemistry (107): 104-115.
USEPA 2017. Regional Screening Levels (RSLs) for Chemical Contaminants at Superfund Sites. United States Environmental Protection Agency, https://www.epa.gov/risk/regional-screening-levels-rsls-generic-tables-june-2017 (accessed 15 November 2017, target hazard quotient 1.0).
AC Acid consuming material. Defined as NAF material which has a NAPP value in excess of -100 kg H2SO4/t
ANC Acid Neutralising Capacity. A process where a sample is reacted with excess 0.5 m HCl at a pH of about 1.5, for 2-3 hours at 80-90ºC followed by back-titration to pH=7 with sodium hydroxide. This determines the acid consumed by soluble materials in the sample.
amphoteric Metal or metalloid that is soluble in both acidic and alkaline media.
AP Acid Potential. Similar to MPA, but only is based on the amount of sulfide-sulfur (calculated at the difference between total sulfur and sulfate-sulfur (SO4-S)) rather than total sulfur. AP (kg H2SO4/t) = (Total S – SO4-S) x 30.6.
circum-neutral pH pH value near 7.
CRS Chromium Reducible Sulfur. The standard CRS method (ISO 148388-2:2014) measures acid volatile sulfur (sulfur volatilised as H2S gas by reaction of sulfides with dilute acid) and H2S produced by reduction of Sn2- ions (n ≥2) with chromous (Cr2+) ions.
EC Electrical conductivity. A measurement of solution salinity.
Conversion: 1,000 µS/cm = 1 dS/m = 1 mS/cm
feldspar Abundant rock forming aluminosilicate mineral with substitution varieties of potassium, calcium and sodium.
MPA Maximum Potential Acidity. A calculation where the total sulfur in the sample is assumed to all be present as pyrite. This value is multiplied by 30.6 to produce a value known as the Maximum Potential Acidity reported in units of kg H2SO4/t.
NAF Non Acid Forming.
NAG Net Acid Generation. A process where a sample is reacted with 15% hydrogen peroxide solution at pH = 4.5 to oxidise all sulfides and then time allowed for the solution to react with acid soluble materials. This is a direct measure of the acid generating capacity of the sample but can be affected by the presence of organic materials.
NAGpH The pH after the NAG test with hydrogen peroxide and heating is completed i.e. oxidation of all sulfides.
NAPP Net Acid Producing Potential. NAPP (kg H2SO4/t) = AP – ANC.
oleic acid A long chain monounsaturated fatty acid with the chemical formula C18H34O2. Fatty acid or soap flotation of spodumene is a well-established method for producing lithium concentrates from pegmatite ore.
oxidisable sulfur A form of sulfur (sulfide, S2-) that reacts with oxygen and water to form sulfuric acid (H2SO4). It is estimated as the fraction that remains when sulfate (SO42-) is subtracted from the total sulfur. An alternative method for estimating oxidisable sulfur is by measurement of chromium reducible sulfur.
PAF Potentially Acid Forming.
PAF-LC Potentially Acid Forming – Low Capacity. Waste rock classification for samples with NAPP values less than or equal to 10 kg H2SO4/t.
PAF-HC Potentially Acid Forming – High Capacity. Waste rock classification for samples with NAPP values greater than 10 kg H2SO4/t.
pegmatite Very coarse intrusive igneous rock that commonly consist of quartz, feldspar and mica.
petalite Lithium aluminium tectosilicate [LiAlSi4O10], a secondary source of hard rock lithium which can be converted to spodumene by heating.
pyrite Iron (II) sulfide, FeS2. Pyrite is the most common sulfide minerals and the major acid forming mineral oxidising to produce sulfuric acid.
spodumene Lithium aluminium inosilicate [LiAl(SiO3)2] the primary source of ‘hard rock’ lithium.
Rubidium mg/kg 1,150 to 3,270 2,450 2,820 Not analysed
Titanium mg/kg Not analysed 72 12 Not analysed
Manganese mg/kg 750 to 1,350 1,000 120 80
Sulfur mg/kg <100 to 1,200 30 <10 Not analysed
Phosphorus mg/kg Not analysed 990 320 Not analysed
Tin mg/kg 29 to 64 70 <10 <2
Lead mg/kg 6 to 8 10 <10 3
Tantalum mg/kg 37 to 72 80 <10 Not analysed
Niobium mg/kg 48 to 75 90 <10 Not analysed
Silver mg/kg 0.05 – 0.11 Not analysed Not analysed Not analysed
Arsenic mg/kg 6 – 310 Not analysed Not analysed 3
Barium mg/kg 1 to 33 Not analysed Not analysed 3
Beryllium mg/kg 98 to 151 Not analysed Not analysed <1
Cadmium mg/kg 0.15 to 0.41 Not analysed Not analysed 8
Cobalt mg/kg 0.4 to 14 Not analysed Not analysed 5
Chromium mg/kg 14 to 196 Not analysed Not analysed <1
Copper mg/kg 3 to 21 Not analysed Not analysed 5
Molybdenum mg/kg 2.4 to 4.6 Not analysed Not analysed <1
Nickel mg/kg 1 to 56 Not analysed Not analysed 5
Antimony mg/kg 0.2 to 0.9 Not analysed Not analysed <7
Selenium mg/kg <0.5 Not analysed Not analysed <2
Thorium mg/kg 1.3 to 2.5 Not analysed Not analysed Not analysed
Uranium mg/kg 2.4 to 4.0 Not analysed Not analysed Not analysed
Vanadium mg/kg 1 to 54 Not analysed Not analysed Not analysed
Zinc mg/kg 75 to 99 Not analysed Not analysed 70
Mercury mg/kg Not analysed Not analysed Not analysed <0.1
*This analysis done on reverse aqua regia digestion for environmentally available metals versus other results which are true totals by four acid digestion.
Determination of various metals by ICP-MS. METALS-022
Determination of Mercury by Cold Vapour AAS. METALS-021
Metals in soil and water by ICP-OES.METALS-020
Leaching Environment Assessment Framework (LEAF) methods of leaching using USEPA methods SW846 1313, 1314, 1315 or 1316.
INORG-125
Total Organic Carbon using APHA latest edition 5310B. DOC is filtered prior to determination.INORG-079
Chromium Reducible Sulfur - Hydrogen Sulfide is quantified by iodometric titration after distillation to determine potential acidity. Based on Acid Sulfate Soils Laboratory Methods Guidelines, Version 2.1 - June 2004.
INORG-068
Fluoride determined by ion selective electrode (ISE) based on APHA latest edition, 4500-F-C. Soils reported from a 1:5 water extract unless otherwise specified.
INORG-026
Conductivity and Salinity - measured using a conductivity cell at 25°C based on APHA latest edition Method 2510. Soils reported from a 1:5 water extract unless otherwise specified.
INORG-002
pH - Measured using pH meter and electrode base on APHA latest edition, Method 4500-H+. Please note that the results for water analyses may be indicative only, as analysis can be completed outside of the APHA recommended holding times. Soils are reported from a 1:5 water extract unless otherwise specified.
INORG-001
Acid Mine Drainage determined by AMIRA International - Acid Rock Drainage Test Handbook.AMD-001
Methodology SummaryMethod ID
MPL Reference: 203076
R01Revision No:
Page | 11 of 13
Client Reference: MRLMMCFW - Earl Grey Lithium
Not ReportedNR
National Environmental Protection MeasureNEPM
Not specifiedNS
Laboratory Control SampleLCS
Relative Percent DifferenceRPD
Greater than>
Less than<
Practical Quantitation LimitPQL
Insufficient sample for this testINS
Test not requiredNA
Not testedNT
Result Definitions
Australian Drinking Water Guidelines recommend that Thermotolerant Coliform, Faecal Enterococci, & E.Coli levels are less than1cfu/100mL. The recommended maximums are taken from "Australian Drinking Water Guidelines", published by NHMRC & ARMC2011.
Surrogates are known additions to each sample, blank, matrix spike and LCS in a batch, of compounds whichare similar to the analyte of interest, however are not expected to be found in real samples.
Surrogate Spike
This comprises either a standard reference material or a control matrix (such as a blank sand or water) fortifiedwith analytes representative of the analyte class. It is simply a check sample.
LCS (LaboratoryControl Sample)
A portion of the sample is spiked with a known concentration of target analyte. The purpose of the matrix spikeis to monitor the performance of the analytical method used and to determine whether matrix interferencesexist.
Matrix Spike
This is the complete duplicate analysis of a sample from the process batch. If possible, the sample selectedshould be one where the analyte concentration is easily measurable.
Duplicate
This is the component of the analytical signal which is not derived from the sample but from reagents,glassware etc, can be determined by processing solvents and reagents in exactly the same manner as forsamples.
Blank
Quality Control Definitions
MPL Reference: 203076
R01Revision No:
Page | 12 of 13
Client Reference: MRLMMCFW - Earl Grey Lithium
Measurement Uncertainty estimates are available for most tests upon request.
Where sampling dates are not provided, Envirolab are not in a position to comment on the validity of the analysis whererecommended technical holding times may have been breached.
When samples are received where certain analytes are outside of recommended technical holding times (THTs), the analysis hasproceeded. Where analytes are on the verge of breaching THTs, every effort will be made to analyse within the THT or as soon aspracticable.
In circumstances where no duplicate and/or sample spike has been reported at 1 in 10 and/or 1 in 20 samples respectively, thesample volume submitted was insufficient in order to satisfy laboratory QA/QC protocols.
Matrix Spikes, LCS and Surrogate recoveries: Generally 70-130% for inorganics/metals; 60-140% for organics (+/-50% surrogates)and 10-140% for labile SVOCs (including labile surrogates), ultra trace organics and speciated phenols is acceptable.
Duplicates: <5xPQL - any RPD is acceptable; >5xPQL - 0-50% RPD is acceptable.
For VOCs in water samples, three vials are required for duplicate or spike analysis.
Spikes for Physical and Aggregate Tests are not applicable.
Filters, swabs, wipes, tubes and badges will not have duplicate data as the whole sample is generally extracted during sampleextraction.
Duplicate sample and matrix spike recoveries may not be reported on smaller jobs, however, were analysed at a frequency to meetor exceed NEPM requirements. All samples are tested in batches of 20. The duplicate sample RPD and matrix spike recoveries forthe batch were within the laboratory acceptance criteria.
Laboratory Acceptance Criteria
MPL Reference: 203076
R01Revision No:
Page | 13 of 13
Envirolab Services (WA) Pty Ltd trading as MPL Laboratories
Chromium Reducible Sulfur - Hydrogen Sulfide is quantified by iodometric titration after distillation to determine potential acidity. Based on Acid Sulfate Soils Laboratory Methods Guidelines, Version 2.1 - June 2004.
INORG-068
Conductivity and Salinity - measured using a conductivity cell at 25°C based on APHA latest edition Method 2510. Soils reported from a 1:5 water extract unless otherwise specified.
INORG-002
pH - Measured using pH meter and electrode base on APHA latest edition, Method 4500-H+. Please note that the results for water analyses may be indicative only, as analysis can be completed outside of the APHA recommended holding times. Soils are reported from a 1:5 water extract unless otherwise specified.
INORG-001
Acid Mine Drainage determined by AMIRA International - Acid Rock Drainage Test Handbook.AMD-001
Australian Drinking Water Guidelines recommend that Thermotolerant Coliform, Faecal Enterococci, & E.Coli levels are less than1cfu/100mL. The recommended maximums are taken from "Australian Drinking Water Guidelines", published by NHMRC & ARMC2011.
Surrogates are known additions to each sample, blank, matrix spike and LCS in a batch, of compounds whichare similar to the analyte of interest, however are not expected to be found in real samples.
Surrogate Spike
This comprises either a standard reference material or a control matrix (such as a blank sand or water) fortifiedwith analytes representative of the analyte class. It is simply a check sample.
LCS (LaboratoryControl Sample)
A portion of the sample is spiked with a known concentration of target analyte. The purpose of the matrix spikeis to monitor the performance of the analytical method used and to determine whether matrix interferencesexist.
Matrix Spike
This is the complete duplicate analysis of a sample from the process batch. If possible, the sample selectedshould be one where the analyte concentration is easily measurable.
Duplicate
This is the component of the analytical signal which is not derived from the sample but from reagents,glassware etc, can be determined by processing solvents and reagents in exactly the same manner as forsamples.
Blank
Quality Control Definitions
MPL Reference: 203076-B
R03Revision No:
Page | 9 of 10
Client Reference: MRLMMCFW - Earl Grey Lithium
Measurement Uncertainty estimates are available for most tests upon request.
Where sampling dates are not provided, Envirolab are not in a position to comment on the validity of the analysis whererecommended technical holding times may have been breached.
When samples are received where certain analytes are outside of recommended technical holding times (THTs), the analysis hasproceeded. Where analytes are on the verge of breaching THTs, every effort will be made to analyse within the THT or as soon aspracticable.
In circumstances where no duplicate and/or sample spike has been reported at 1 in 10 and/or 1 in 20 samples respectively, thesample volume submitted was insufficient in order to satisfy laboratory QA/QC protocols.
Matrix Spikes, LCS and Surrogate recoveries: Generally 70-130% for inorganics/metals; 60-140% for organics (+/-50% surrogates)and 10-140% for labile SVOCs (including labile surrogates), ultra trace organics and speciated phenols is acceptable.
Duplicates: <5xPQL - any RPD is acceptable; >5xPQL - 0-50% RPD is acceptable.
For VOCs in water samples, three vials are required for duplicate or spike analysis.
Spikes for Physical and Aggregate Tests are not applicable.
Filters, swabs, wipes, tubes and badges will not have duplicate data as the whole sample is generally extracted during sampleextraction.
Duplicate sample and matrix spike recoveries may not be reported on smaller jobs, however, were analysed at a frequency to meetor exceed NEPM requirements. All samples are tested in batches of 20. The duplicate sample RPD and matrix spike recoveries forthe batch were within the laboratory acceptance criteria.
Laboratory Acceptance Criteria
MPL Reference: 203076-B
R03Revision No:
Page | 10 of 10
Envirolab Services (WA) Pty Ltd trading as MPL Laboratories
Results are reported on a dry weight basis for solids and on an as received basis for other matrices.
Samples were analysed as received from the client. Results relate specifically to the samples as received.
Please refer to the following pages for results, methodology summary and quality control data.
Analysis Details
Tests not covered by NATA are denoted with *Accredited for compliance with ISO/IEC 17025 - Testing.
NATA Accreditation Number 2901. This document shall not be reproduced except in full.
01/12/2017Date of Issue
01/12/2017Date results requested by
Report Details
Todd Lee, Laboratory Manager
Authorised By
Joshua Lim, Operations Manager
Results Approved By
Revision No: R00
203076-CMPL Reference: Page | 1 of 8
Client Reference: MRLMMCFW - Earl Grey Lithium
1,60019,000mg/kgIron
3100mg/kgBarium
<12mg/kgBeryllium
<717mg/kgAntimony
80560mg/kgManganese
1290mg/kgZinc
<22mg/kgSelenium
22mg/kgTin
5380mg/kgNickel
<1110mg/kgMolybdenum
<0.1<0.1mg/kgMercury
347mg/kgLead
<116mg/kgCobalt
5140mg/kgCopper
8880mg/kgChromium
<0.40.7mg/kgCadmium
36mg/kgArsenic
30/11/201730/11/2017-Date analysed
30/11/201730/11/2017-Date digested
SoilSoilType of sample
P17100152P17100151UNITSYour Reference
203076-C-2203076-C-1Our Reference
17 Metals in soil
MPL Reference: 203076-C
R00Revision No:
Page | 2 of 8
Client Reference: MRLMMCFW - Earl Grey Lithium
MediumExtreme-Reaction Rate*
5.41.9pH UnitspHFOX (field peroxide test)*
28/11/201728/11/2017-Date analysed
28/11/201728/11/2017-Date prepared
SoilSoilType of sample
P17100152P17100151UNITSYour Reference
203076-C-2203076-C-1Our Reference
sPOCAS field test
MPL Reference: 203076-C
R00Revision No:
Page | 3 of 8
Client Reference: MRLMMCFW - Earl Grey Lithium
Determination of Mercury by Cold Vapour AAS. METALS-021
Metals in soil and water by ICP-OES.METALS-020
pH- measured using pH meter and electrode. Soil is oxidised with Hydrogen Peroxide or extracted with water. Based on section H, Acid Sulfate Soils Laboratory Methods Guidelines, Version 2.1 - June 2004.
Spike Recovery %DuplicateQUALITY CONTROL: sPOCAS field test
MPL Reference: 203076-C
R00Revision No:
Page | 6 of 8
Client Reference: MRLMMCFW - Earl Grey Lithium
Not ReportedNR
National Environmental Protection MeasureNEPM
Not specifiedNS
Laboratory Control SampleLCS
Relative Percent DifferenceRPD
Greater than>
Less than<
Practical Quantitation LimitPQL
Insufficient sample for this testINS
Test not requiredNA
Not testedNT
Result Definitions
Australian Drinking Water Guidelines recommend that Thermotolerant Coliform, Faecal Enterococci, & E.Coli levels are less than1cfu/100mL. The recommended maximums are taken from "Australian Drinking Water Guidelines", published by NHMRC & ARMC2011.
Surrogates are known additions to each sample, blank, matrix spike and LCS in a batch, of compounds whichare similar to the analyte of interest, however are not expected to be found in real samples.
Surrogate Spike
This comprises either a standard reference material or a control matrix (such as a blank sand or water) fortifiedwith analytes representative of the analyte class. It is simply a check sample.
LCS (LaboratoryControl Sample)
A portion of the sample is spiked with a known concentration of target analyte. The purpose of the matrix spikeis to monitor the performance of the analytical method used and to determine whether matrix interferencesexist.
Matrix Spike
This is the complete duplicate analysis of a sample from the process batch. If possible, the sample selectedshould be one where the analyte concentration is easily measurable.
Duplicate
This is the component of the analytical signal which is not derived from the sample but from reagents,glassware etc, can be determined by processing solvents and reagents in exactly the same manner as forsamples.
Blank
Quality Control Definitions
MPL Reference: 203076-C
R00Revision No:
Page | 7 of 8
Client Reference: MRLMMCFW - Earl Grey Lithium
Measurement Uncertainty estimates are available for most tests upon request.
Where sampling dates are not provided, Envirolab are not in a position to comment on the validity of the analysis whererecommended technical holding times may have been breached.
When samples are received where certain analytes are outside of recommended technical holding times (THTs), the analysis hasproceeded. Where analytes are on the verge of breaching THTs, every effort will be made to analyse within the THT or as soon aspracticable.
In circumstances where no duplicate and/or sample spike has been reported at 1 in 10 and/or 1 in 20 samples respectively, thesample volume submitted was insufficient in order to satisfy laboratory QA/QC protocols.
Matrix Spikes, LCS and Surrogate recoveries: Generally 70-130% for inorganics/metals; 60-140% for organics (+/-50% surrogates)and 10-140% for labile SVOCs (including labile surrogates), ultra trace organics and speciated phenols is acceptable.
Duplicates: <5xPQL - any RPD is acceptable; >5xPQL - 0-50% RPD is acceptable.
For VOCs in water samples, three vials are required for duplicate or spike analysis.
Spikes for Physical and Aggregate Tests are not applicable.
Filters, swabs, wipes, tubes and badges will not have duplicate data as the whole sample is generally extracted during sampleextraction.
Duplicate sample and matrix spike recoveries may not be reported on smaller jobs, however, were analysed at a frequency to meetor exceed NEPM requirements. All samples are tested in batches of 20. The duplicate sample RPD and matrix spike recoveries forthe batch were within the laboratory acceptance criteria.
Laboratory Acceptance Criteria
MPL Reference: 203076-C
R00Revision No:
Page | 8 of 8
Envirolab Services (WA) Pty Ltd trading as MPL Laboratories
Chromium Reducible Sulfur - Hydrogen Sulfide is quantified by iodometric titration after distillation to determine potential acidity. Based on Acid Sulfate Soils Laboratory Methods Guidelines, Version 2.1 - June 2004.
INORG-068
pH- measured using pH meter and electrode. Soil is oxidised with Hydrogen Peroxide or extracted with water. Based on section H, Acid Sulfate Soils Laboratory Methods Guidelines, Version 2.1 - June 2004.
INORG-063
Conductivity and Salinity - measured using a conductivity cell at 25°C based on APHA latest edition Method 2510. Soils reported from a 1:5 water extract unless otherwise specified.
INORG-002
pH - Measured using pH meter and electrode base on APHA latest edition, Method 4500-H+. Please note that the results for water analyses may be indicative only, as analysis can be completed outside of the APHA recommended holding times. Soils are reported from a 1:5 water extract unless otherwise specified.
INORG-001
Acid Mine Drainage determined by AMIRA International - Acid Rock Drainage Test Handbook.AMD-001
Spike Recovery %DuplicateQUALITY CONTROL: sPOCAS field test
MPL Reference: 204413
R00Revision No:
Page | 10 of 12
Client Reference: KRLEGGC
Not ReportedNR
National Environmental Protection MeasureNEPM
Not specifiedNS
Laboratory Control SampleLCS
Relative Percent DifferenceRPD
Greater than>
Less than<
Practical Quantitation LimitPQL
Insufficient sample for this testINS
Test not requiredNA
Not testedNT
Result Definitions
Australian Drinking Water Guidelines recommend that Thermotolerant Coliform, Faecal Enterococci, & E.Coli levels are less than1cfu/100mL. The recommended maximums are taken from "Australian Drinking Water Guidelines", published by NHMRC & ARMC2011.
Surrogates are known additions to each sample, blank, matrix spike and LCS in a batch, of compounds whichare similar to the analyte of interest, however are not expected to be found in real samples.
Surrogate Spike
This comprises either a standard reference material or a control matrix (such as a blank sand or water) fortifiedwith analytes representative of the analyte class. It is simply a check sample.
LCS (LaboratoryControl Sample)
A portion of the sample is spiked with a known concentration of target analyte. The purpose of the matrix spikeis to monitor the performance of the analytical method used and to determine whether matrix interferencesexist.
Matrix Spike
This is the complete duplicate analysis of a sample from the process batch. If possible, the sample selectedshould be one where the analyte concentration is easily measurable.
Duplicate
This is the component of the analytical signal which is not derived from the sample but from reagents,glassware etc, can be determined by processing solvents and reagents in exactly the same manner as forsamples.
Blank
Quality Control Definitions
MPL Reference: 204413
R00Revision No:
Page | 11 of 12
Client Reference: KRLEGGC
Measurement Uncertainty estimates are available for most tests upon request.
Where sampling dates are not provided, Envirolab are not in a position to comment on the validity of the analysis whererecommended technical holding times may have been breached.
When samples are received where certain analytes are outside of recommended technical holding times (THTs), the analysis hasproceeded. Where analytes are on the verge of breaching THTs, every effort will be made to analyse within the THT or as soon aspracticable.
In circumstances where no duplicate and/or sample spike has been reported at 1 in 10 and/or 1 in 20 samples respectively, thesample volume submitted was insufficient in order to satisfy laboratory QA/QC protocols.
Matrix Spikes, LCS and Surrogate recoveries: Generally 70-130% for inorganics/metals; 60-140% for organics (+/-50% surrogates)and 10-140% for labile SVOCs (including labile surrogates), ultra trace organics and speciated phenols is acceptable.
Duplicates: <5xPQL - any RPD is acceptable; >5xPQL - 0-50% RPD is acceptable.
For VOCs in water samples, three vials are required for duplicate or spike analysis.
Spikes for Physical and Aggregate Tests are not applicable.
Filters, swabs, wipes, tubes and badges will not have duplicate data as the whole sample is generally extracted during sampleextraction.
Duplicate sample and matrix spike recoveries may not be reported on smaller jobs, however, were analysed at a frequency to meetor exceed NEPM requirements. All samples are tested in batches of 20. The duplicate sample RPD and matrix spike recoveries forthe batch were within the laboratory acceptance criteria.