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HomeMy WebLinkAboutNC0090212_Plan of Action_20221213 (2)Consulting (U.S.), Inc. srk consulting 525 S 5250 Neil Road, Suite 300 Reno, NV 89502 United States +1 775 828 6800 office +1 775 828 6820 fax reno@srk.com www.srk.com Technical Memo December 13, 2022 To Adam Parr, Mining Director, North Carolina Department of Environmental Quality, Division of Energy, Minerals, and Land Resources From Ruth Griffiths, Amy Prestia, Rob Bowell Cc David Miller (DEQ), Toby Vinson (DEQ), Morgan Warren (Albemarle Corporation) Subject Kings Mountain Geochemical Characterization Work Plan Client Albemarle Corporation Project Kings Mountain Project 1 Introduction The following work plan has been prepared by SRK Consulting (U.S.), Inc. (SRK) on behalf of Albemarle Corporation (Albemarle) to provide the North Carolina Department of Environmental Quality Division of Energy, Minerals and Land Resources (DEQ) with a description of the approach and test methods being used for the geochemical characterization of waste rock, ore and tailings at the Kings Mountain Project located in North Carolina. 1.1 Objectives The primary purpose of this investigation is to provide an understanding of the geochemical characteristics of geological materials specific to the Kings Mountain Project and to define the potential for future mining wastes, including tailings, waste rock and pit wall rock, to generate acid or leach deleterious constituents. In order to accomplish the objectives of the study, representative samples have been collected and characterized following guidelines set forth in the Global Acid Rock Drainage (GARD) Guide (INAP, 2014), the MEND Prediction Manual for Drainage Chemistry from Sulfidic Geologic Materials (MEND, 2009) and the Bureau of Land Management Instruction Memorandum NV- 2010-014, Nevada Bureau of Land Management Rock Characterization Resources and Water Analysis Guidance for Mining Activities (BLM, 2013). These are internationally recognized guidance documents for the geochemical characterization of geological materials and are derived from best practices of the mining industry, government, academia and community groups conducting mine site drainage chemistry predictions. Recognizing that the work performed as part of the geochemical characterization study will be integrated into the subsequent permitting documents prepared for the site, SRK developed an approach for a purpose-built characterization that focuses on the following aspects: Assessment of waste rock geochemistry to provide a prediction of the potential geochemical reactivity and stability of future waste rock and construction material for the project, and to SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 Kings Mountain Geochemical Characterization Work Plan Technical Memo determine potential contact water (run-off and seepage) chemistry associated with the future mine facilities. Evaluation of tailings material geochemistry to provide a prediction of contact water chemistry that may change over time and would influence the design, operation and closure of the Tailings Storage Facility (TSF). Determination of final pit wall geochemistry to define the control that the pit wall rocks would have on the chemistry of waters removed from the pit during operation and pit lake that will form after closure. The results of the geochemical characterization testwork will provide a basis for the assessment for Acid Rock Drainage and Metal Leaching (ARDML) and will support predictions of future contact water quality (i.e., runoff and groundwater that contacts waste rock or pit walls). In turn, these results will be used to inform decisions on engineering designs, mine planning and waste rock and tailings management. The purpose of this memorandum is to provide a detailed description of the geochemical characterization program design, in particular the Leaching Environmental Assessment Framework (LEAF) test methodology, and to obtain approval from DEQ on the approach and scope of the program. This memorandum includes a summary of the static test data available to date that supports the design of the LEAF and kinetic test programs and elaborates on the information provided by SRK in the October 6, 2022 meeting with DEQ. Full details of the characterization program methodology and results will be presented in a comprehensive geochemical characterization report. 2 Background 2.1 Project Location The Kings Mountain Project is located in southwestern North Carolina, USA, adjacent to the city of Kings Mountain on the 1-85 transit corridor, approximately 33 miles west of the city of Charlotte (Figure 2-1). The Property is located at approximately 35 degrees, 13 minutes north latitude and 81 degrees, 21 minutes west longitude. 2.2 Project Climate South -Central North Carolina is situated in a humid subtropical climate (Cfa) per the Koppen climate classification system. This climate is generally characterized by hot humid precipitous summers and cold drier winters. Average winter temperatures vary between 30 degrees Fahrenheit (°F) to 50°F. Average summer temperatures vary between 70OF to 90°F. Average monthly precipitation varies between 3 inches and 5 inches. Average annual precipitation is 42 inches, with an even distribution of rainfall throughout the year and an average annual snowfall of 4 inches. South -Central North Carolina is prone to thunderstorms during the summer and ice storms during the winter. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 Kings Mountain Geochemical Characterization Work Plan Technical Memo Kings Mobritain i" 001, // M' pmvY . ® OpenSI—Nap (and) wntnbutors• CC-BKSA i Mer p, 7+� FID®77 ■ North Carolina �eluc Kd �r4 I J\1 N�ntNsnik ''Garr• Ik n J -_ Duncan spartanburg Greenvi� South Carolina . Mau,din r sin, ,de , - Un- Sumter { NationalForest i� Neiberry Legend Geen,�• pd I _` �-C "Miles O Kings Mountain Project 0 10 20 Dawm: •- tiro„•,. µAD_1d9a_5�9ePlq�_Norbr_Cpmlin_rIPS 3200_r— 1 _2 000 000 e ( nd) eonlnbut rs. CC -BY -SA E -N14D' 22Ba Avmw�ry: EPSC OP trW(atl Figure 2-1: Location Map 2.3 Geology and Mineralization As described by SRK (2021), North Carolina's tin-spodumene belt lies within the Inner Piedmont terrane, an orogenic core formed during the Devonian -Mississippian, Acadian-Neoacadian orogeny of the southern Appalachians. The Inner Piedmont stretches for some 700 kilometers (km) strike length from Winston-Salem in North Carolina to the Coastal Plain in Alabama, bound between the Brevard Fault Zone (BFZ) to the northwest and the Central Piedmont Suture (CPS) to the southeast (Merschat et al., 2012). Rocks of the Eastern Inner Piedmont, the Cat Square terrane, are unconformably abutted against the exotic peri-Gondwanan Carolina super terrane along the CPS; spodumene pegmatites, SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 3 Kings Mountain Geochemical Characterization Work Plan Technical Memo hosted by rocks of the Cat Square terrane, occur along a reactivation of this major tectonic boundary, the Kings Mountain shear zone (KMSZ). In the Kings Mountain area, the Cat Square terrane is composed of amphibolites, mica schist, and mica gneiss; these are interpreted to represent the deposition of pelitic sediments, with subsequent mafic and ultramafic intrusions, in the remnant Iapetus Ocean basin that existed between Laurentia and the Carolina superterrane. Mississipian aged Cherryvile Granite, granite pegmatite, and spodumene pegmatites intrude the mica schist and amphibolite units of the Cat Square terrane along the KMSZ. Spodumene pegmatites, averaging up to 20% spodumene, vary in thickness and overall extent; hundreds of these spodumene pegmatite dikes occur in the Kings Mountain area, with most less than 10 feet (ft) thick while the largest spodumene pegmatite dikes are approximately 400 ft thick and 3,300 ft long. The Kings Mountain deposit is a Lithium -bearing rare -metal pegmatite intrusion that has penetrated along the KMSZ. The pegmatite field at Kings Mountain is approximately 1,500 ft wide at its widest point in the historic pit area and narrows to approximately 400 to 500 ft in width at its narrowest point south of the historic pit. The lithium mineralization at the Kings Mountain deposit occurs within albite- spodumene pegmatites and to a lesser extent within metamorphosed altered wallrock adjacent to mineralized pegmatites. A generalized stratigraphic column is provided in Figure 2-2. 480 �L ~ (D O upper mica Schist N■ (upper mica sch) no E (i 0) &CL _ 540 N O in l0 E W +cc amphibole 's O d gneiss -schist (amp N 560 R gn-sch); shear schist i= (shear schist) d cc H d � c c� S80 U- � E 600 C) C v U)O N8 •N 14 / mica schist (mica sch) N / M® 620 0 U d 640 O v a silica mica schist (silica 0 O_ mica sch): silica mica •_ �j ++ im C schist - marble E 66o Z O i transition zone (sc►t-mbl) > 0 C H — 2 ~ 680 7 N — —_ — marble (mbl) C O C N H L rn 700 CY1 C U phyllite (phyllite) Figure 2-2: Generalized Stratigraphic Column ■ SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 Kings Mountain Geochemical Characterization Work Plan Technical Memo A detailed geological model has been developed by Albemarle and various consultants as part of the exploration program and to provide information for mine planning purposes. A plan view and cross - sectional view of the geologic model from SRK (2021) is provided in Figure 2-3 and Figure 2-4. Development of this geological model is ongoing and the geologic interpretations are subject to change. A total of twelve material types have been identified for the purposes of the Kings Mountain geochemical characterization program based on lithology and grade (i.e., ore versus waste). The Kings Mountain material types are summarized in Table 2-1 along with the estimated proportions to be mined based on the current mine plan and geologic model. The material type proportions in Table 2-1 may change as the geologic interpretation of the deposit evolves, and the geologic model is updated. Table 2-1: Kings Mountain Geochemical Program Material Types Category Main Material Type Estimated Percentage of Total to be Mined' Waste Rock Overburden 1.3% Amphibolite Gneiss -Schist 45.5% Biotite Gneiss 3.2% Mica Schist 10% Pyrrhotite (Po) Mica Schist 5% Upper Mica Schist 6.2% Shear Schist 4.2% Silica Mica Schist 3.7% Diabase <1 % Granite <1 % Ore Pegmatite 0.9% Spodumene Pegmatite 19.3% 'Proportions are an estimate and subject to change based on ongoing modeling and mine planning. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 5 Kings Mountain Geochemical Characterization Work Plan Technical Memo _ Full -Rock Name_ � Merged2016 ��t ■ Amphibole Gneiss -Schist rn m m Chlorite Schist ■Marble Mica Schist i Peg y d7j h Sear Shear Schist ■Silica Mica Schist ■Spod Peg Upper Mica Schist 1 +543000 N ` 4 i ' a 1� 3E 1 fr' Air +541500 N F Looking down v o + m 0 549 1000 1500 �! Figure 2-3: Geologic Model Plan View SRK CONSULTING (U.S.), INC. ■ DECEMBER 13, 2022 6 Kings Mountain Geochemical Characterization Work Plan Technical Memo Full Rock Name Mlerg-ed_2018 ■Amphibole Gneiss -Schist ■Amphilbolite ■Aplite ■Chlorite Schist Ilk" Dia base 0 Granite Mafic ■ Marble Mica Schist All' ■ Musc Peg ■ NR ■ Overburden Peg +600 phyllite Quartzolite ■ Schist - Marble Shear Schist ■Silica Mica Schist ■Spod Peg Upper Mica Schist ■ ter +-300 +300 N, 00 Plunge 00 Azimuth 015 0 100 200 300 Figure 2-4: Geologic Model Cross -Sectional View SRK CONSULTING (U.S.), INC. m DECEMBER 13,2022 Kings Mountain Geochemical Characterization Work Plan Technical Memo 3 Mine Plan, Conceptual Model and Program Design A conceptual geochemical model has been developed based on the deposit geology combined with the proposed mining and processing methods. This conceptual model provides the basis for the scope and methodology of the geochemistry baseline study and defines the approach for sample selection, laboratory procedures and key criteria for decision -making throughout the process. The Project will be developed as an expansion of a previously mined open pit. The Albemarle owned site has an existing lithium conversion plant and research/administrative facility. The primary project includes redevelopment of the open pit, spodumene concentrator and associated infrastructure, and construction of waste rock/tailings storage facilities. Ore and waste rock will be mined using conventional open pit mining techniques including drill and blast, loading and truck haulage. Mining will take place below the regional water table and the pit will be flooded upon closure of the mine. Waste rock will be generated from mining and placed in waste rock storage facilities. Potentially acid generating (PAG) waste rock mined from the pit will be managed to mitigate risks to the environment. The operation will employ dry stack tailings technologies to reduce the amount of water required in the mining process, improve the stability of the TSF, and minimize the overall footprint of the operation. Dry stack tailings technology removes most of the moisture from the tailings slurry mixture. The design of the geochemical characterization program has been developed based on the geology of the site and the mine plan information. Table 3-1 provides a list of the mine materials that will require geochemical characterization and the types of geochemical data required. Because Albemarle is currently evaluating variations within the mineral processing flow sheet including ore sorting, magnetic separations, and dense media separation (DMS), the specific type of waste produced may change. The potential waste streams that will be generated from the lithium extraction process are summarized in Table 3-1; however, the waste streams and management of these waste streams may change as the ongoing metallurgical testing program and the flow sheet are finalized. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 Kings Mountain Geochemical Characterization Work Plan Technical Memo Table 3-1: Program Design Mine Component/ Location Duration Composition Material Geochemical Characterization Test Methods Facility Available for Characterization ABA, Mineralogy EPA LEAF HCT NAG, 1312 ICP (SPLP) EPA 1313 EPA 1314 EPA 1315 EPA 1316 (pH) (Upflow) (Diffusion) (L/S) Waste rock Mine area Permanent Non-PAG and PAG Core' X X X X X X storage facilities Waste rock Sonic core X -- X Ore sorting rejects Met program3 X X X X X X DMS material Met program3 X X X X X Material from magnetic Met program3 X X X separation Ore stockpiles Plant site Temporary Ore grade material Core' X X X X X Pit walls Open pit Permanent Waste rock and low- Core' X X X X X X grade ore Pit backfill Open pit Permanent Non-PAG and PAG Core' X X X X X X X Waste rock Sonic core X -- X Dry stack TSF Mine area Permanent Flotation tails Met program3 X X X X X X X Sonic core' X -- X Reclamation Various Permanent Soil for reclamation Sonic core X -- X covers (pre -strip) Borrow areas Various Permanent Non-PAG waste rock Core' X -- X X for construction material ' Core from exploration drillholes throughout the deposit (unweathered) 2 Sonic core from legacy facilities (weathered) 3 Residues from metallurgical testwork programs ° Sonic core from holes drilled into alluvium within mine facility footprints Note: The ore processing flow sheet is still under development and the information in this table may change as the details are finalized SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 9 Kings Mountain Geochemical Characterization Work Plan Technical Memo 4 Waste Rock Characterization 4.1 Waste Rock and Ore Sample Collection Sample selection is a fundamental step in any geochemical characterization program. The number of samples selected for testing is typically based on the number of discrete material types identified for a deposit as well as the relative percentage of each material type predicted to be mined according to the geologic model. For the Kings Mountain geochemical characterization program, material types have been delineated based on lithology and grade (i.e., ore vs. waste) as described above. A total of 474 samples representative of future waste rock and ore have been collected from exploration drill core for geochemical characterization testing. The samples are summarized in Table 4-1 and are shown in the context of the future pit in Figure 4-1. The material type proportions in Table 4-1 may change as the geologic interpretation of the deposit evolves, and the geologic model is updated. However, the number and location of samples is still considered representative and adequate to characterize the material associated with the Project and predict water quality for the future mine facilities. In addition, samples of waste rock are being collected from existing (legacy) waste rock piles from previous operations. The purpose of these samples is to compare the geochemistry of fresh rock (i.e., core) to weathered rock material that has been exposed to oxygen and water for over 50 years. This will provide an indication of the soluble weathering products that developed as a result of weathering that are available for leaching from this material. An estimated 20 to 40 samples of legacy waste will be collected during the ongoing drill program. 4.2 Waste Rock and Ore Characterization Test Methods The geochemical test methods selected for this Project include both static and kinetic testing that are designed to address the bulk geochemical characteristics of the samples, and to assess the potential of waste rock and ore materials to generate acid or release metals into solution. "Static testing" is a general term describing those analytical methods applied to characterize acid generation and metal leaching characteristics of material at the time of testing and does not account for temporal changes that may occur in the material as chemical weathering proceeds. Static tests provide a balance of acid generating and acid consuming reactions at an end point and may be used to determine the potential magnitude of metals leaching from a given material. Static testing is distinguished from "kinetic tests", which evaluate the rate of sulfide oxidation and metal release over time. Static testing provides a conservative approximation of acid generation and trace metal release potential, which is used to determine whether more comprehensive kinetic testing is warranted. Based on the results of the static tests, materials that exhibit uncertain or highly variable geochemical behavior may require further characterization using kinetic test methods to determine the rates and character of longer -term leaching. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 10 Kings Mountain Geochemical Characterization Work Plan Technical Memo The geochemical test methods for the Kings Mountain Project have been selected to determine the total acid generating or neutralizing potential of the samples and assess the concentration of constituents in leachates that could be derived from the material. Static and kinetic testing methodologies include the following: Multi -element analysis using four -acid digestion followed by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) or ICP Atomic Emission Spectroscopy analysis (ICP-AES) to determine total chemistry for 48 elements plus mercury (ALS Chemex Method ME-MS61 m) Measurements of paste pH Acid Base Accounting (ABA) using the modified Sobek method (Sobek et al., 1978) with sulfur speciation by hydrochloric acid and nitric acid extraction Net Acid Generating (NAG) testing that reports the final NAG pH and final NAG value after a two - stage hydrogen peroxide (H2O2) digest (Miller et al., 1997) Synthetic Precipitation Leaching Procedure (SPLP) testing (US EPA, 1994) and analysis of leachate Leaching Environmental Assessment Framework (LEAF) testing using the EPA 1313, 1314 and 1316 methodologies (US EPA, 2012a;b; US EPA, 2017a) Humidity Cell Test (HCT) Procedure (ASTM D5744-96), including analysis of extracts Mineralogical analysis, including optical microscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), QEMSCAN and TIMA. A sample matrix summarizing the number of waste rock and ore samples submitted for each test is provided in Table 4-1 and full details of the test methods are provided in the following sections. At the time of writing, the ABA, NAG and multi -element analysis is complete, and the SPLP, LEAF, HCT and mineralogy work is in progress. Samples collected from the legacy waste rock and ore piles onsite will be submitted for ABA, NAG and multi -element analysis. Based on the results of this testing, a sub -set of samples will be selected for mineralogy, SPLP and LEAF testing. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 11 Kings Mountain Geochemical Characterization Work Plan Technical Memo Table 4-1: Waste Rock and Ore Sample Frequency and Testing Matrix Category Main Material Type Estimated ABA/NAG/ HCT/ Modified LEAF EPA Percentage Multi- Mineralogy SPLP, LEAF 1314 of Total to be Element (optical, (EPA 1313 (in Mined (complete) SEM, XRD) and 1316), progress) (in Mineralogy progress) (XRD) (in progress) Waste Overburden 1.3% 5 1 0 0 Rock Amphibolite Gneiss -Schist 45.5% 116 5 4 2 Biotite Gneiss 3.2% 31 2 3 1 Mica Schist 10% 44 3 3 2 Pyrrhotite (Po) Mica Schist 5% 39 2 2 1 Upper Mica Schist 6.2% 12 2 1 1 Shear Schist 4.2% 49 3 4 2 Silica Mica Schist 3.7% 8 1 1 1 Diabase <1 % 2 0 0 0 Granite <1% 2 0 0 0 Ore Pegmatite 0.9% 109 2 3 0 Spodumene Pegmatite 19.3% 57 1 2 0 Total 474 22 23 10 Figure 4-1: Geochemical Characterization Samples in Context of Final Pit Shell SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 12 Kings Mountain Geochemical Characterization Work Plan Technical Memo 4.2.1 Static Testing Acid Base Accounting ABA provides an industry -recognized assessment of the acid generation or acid neutralization potential of rock materials. It indicates the theoretical potential for a given material to produce net acid conditions. The technique characterizes the `total potential reservoir of acidity or alkalinity in a given material' but does not account for mineralogy, kinetics or other influencing factors controlling natural sulfide oxidation. The ABA method used for the Kings Mountain Project is the Modified Sobek ABA method (Sobek et al., 1978), which includes both laboratory analysis and empirical calculations based on acid potential (AP) and neutralizing potential (NP). An estimate of acid generation is made by assuming complete reaction between all of the minerals with acid potential and all of the minerals with neutralizing potential (essentially dissolution of carbonate minerals and to some extent silicate minerals). The AP values were calculated from sulfide sulfur concentrations and reported as kilograms of calcium carbonate per ton of rock (kg CaCO3 eq/t). The NP values were determined using the Modified Sobek protocol that includes a digestion to expel any CO2 followed by a back titration with NaOH to pH 8.3. Neutralizing potential is calculated as CaCO3 equivalents per ton of rock. The samples were also submitted for determination of total inorganic carbon (TIC) by Leco analysis to provide a second measure of neutralization potential for comparison. Measurements of paste pH are also taken and provide an indication of the availability of the acid neutralizing minerals for buffering The balance between the acid generating mineral phases and acid neutralizing mineral phases is referred to as the net neutralization potential (NNP), which is equal to the difference between NP and AP. The NNP allows classification of the samples as potentially acid consuming or acid producing. A positive value of NNP indicates the sample neutralizes more acid than is produced during oxidation. A negative NNP value indicates there are more acid producing constituents than acid neutralizing constituents. Material that would be considered to have a high potential for acid neutralization produces a net neutralizing potential greater than 20 kg CaCO3/t. Those materials considered to have a higher potential for acid generation produce an NNP less than -20 kg CaCO3/t. ABA data are also assessed using the neutralization potential ratio (NPR), which is calculated by dividing the NP by the AP. NPR values less than 1 indicate a higher potential for acid generation and greater than 3 indicate significant acid neutralization. For the purposes of the King Mountain characterization program, a a site -specific NPR cut-off of 2 has been selected for identifying potentially acid generating material. This site -specific cut-off may be refined based upon the results of the characterization program described herein. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 13 Kings Mountain Geochemical Characterization Work Plan Technical Memo Net Acid Generation Testing Static Net Acid Generation (NAG) testing is being used as a second measure of ARID potential for the Kings Mountain waste rock and ore samples. The static NAG test differs from the ABA test in that it provides a direct empirical estimate of the overall sample reactivity, including any acid generated by semi -soluble sulfate minerals as well as potentially acid -generating sulfide minerals. NAG testing was carried out in accordance with the method described by Miller et al. (1997). The method essentially involves intensive oxidation of the sample using hydrogen peroxide, which accelerates the dissolution of sulfide minerals and has the net result that acid production and neutralization can be measured directly. The leachate is then titrated with sodium hydroxide in two stages (to pH 4.5 and to pH 7) to determine the NAG value, which is calculated as follows: NAG = (Vi it / X) (49 * VNaOH * M) / W Where: NAG = net acid generation (kg H2SO4 per metric ton) Vtnit = volume of initial hydrogen peroxide solution (mQ X = volume used to determine NAG by titration (mL) VNaOH = volume of NaOH used in titration (mQ M = concentration of NaOH used in titration (moles/liter) W = weight of sample reacted (g) Based on the NAG method, the criteria used for assessing the acid generation potential based on NAG results are summarized in Table 4-2. In general, a NAG pH greater than pH 4 and a NAG value equal to zero are indicative of a non-acid generating material. A NAG value greater than one kg H2SO4/t indicates the sample would generate some acidity in excess of available alkalinity. However, by convention, any NAG value below 10 kg H2SO4/t has a limited potential for acid generation and the results are considered inconclusive because a blank hydrogen peroxide solution can generate a NAG artifact value up to 10 kg H2SO4/t (Sapsford et al., 2009). Table 4-2: Acid Generation Criteria for NAG Test Results Acid Generation Capacity Final NAG NAG value pH (s.u.) (kg H2SO4 eglt) Potentially Acid Higher Capacity < 4.5 >10 Generating (PAG) Lower Capacity < 4.5 <10, >1 Non -Acid Generating (non-PAG) > 4.5 0 SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 14 Kings Mountain Geochemical Characterization Work Plan Technical Memo Multi -Element Analysis The Kings Mountain waste rock and ore samples have been submitted for multi -element analysis using the ME-MS61 m method that involves a four -acid digest followed by ICP-MS/ICP-AES analysis to determine total concentrations for 48 elements plus mercury. The four -acid digest is able to dissolve most minerals in the sample matrix and provides near -total quantitative results. Multi -element analysis is a useful screening -level tool for geochemical characterization and the data can be used to evaluate the variation in chemical composition across the deposit or fingerprint different lithologies. When compared to average elemental crustal abundance, multi -element data can also provide an indication of elemental enrichment that may be of environmental importance and can identify parameters that might be of concern for the Project. The soluble or leachable portion of these elements, however, needs to be estimated empirically by leach tests (i.e., SPLP, LEAF or HCT testing), which account for site specific factors that affect mineral solubility. The results of the multi -element analysis are analyzed using the Geochemical Abundance Index (GAI; ]NAP, 2014), which compares the concentration of an element in a given sample to its average crustal abundance. GAI values are particularly useful in determining the relative enrichment of elements based on lithology and may be used to identify elements enriched above average crustal concentrations. GAI values are calculated as follows: GAI =1og2 [C/(1.5*S)] Where C is the concentration of an element as determined from the multi -element assay, and S is the average crustal abundance of the element of interest (Mason, 1966). Materials are then assigned a GAI value between zero and six based on the degree of enrichment (Table 4-3). According to the INAP (2014) protocol, a GAI value greater than three indicates significant enrichment. Table 4-3: Interpretation of GAI Values GAI Value Interpretation 0 < 3 times average crustal concentrations 1 3 to 6 times average crustal concentrations 2 6 to 12 times average crustal concentrations 3 12 to 24 times average crustal concentrations 4 24 to 48 times average crustal concentrations 5 48 to 96 times average crustal concentrations 6 >96 times average crustal concentrations SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 15 Kings Mountain Geochemical Characterization Work Plan Technical Memo 4.2.2 Short-term Leach Testing Synthetic Precipitation Leaching Procedure (SPLP) The Synthetic Precipitation Leaching Procedure (EPA Method 1312) is being conducted on representative composite samples to evaluate the short-term reactivity of waste rock and ore materials associated with the Kings Mountain Project. The SPLP method is an agitated extraction method that requires particle size reduction to less than 9.5 mm. The standard SPLP method uses an extraction solution that has been adjusted with dilute sulfuric/nitric acid to pH 5.0 and is typically run at a 20:1 solution to solid ratio. The high liquid to solid ratio may result in an underestimate of leachability and grain size reduction may increase reactivity. For the Kings Mountain characterization program, a modified SPLP method is being used where the extraction solution consists of D.I. water with no pH adjustment and the solution to solid ratio is 2:1. Due to these modifications, the results of the modified SPLP are more comparable to the Nevada Meteoric Water Mobility Procedure (MWMP) that is frequently used to provide a measure of the readily soluble constituents of mine waste. The results of the SPLP provide a qualitative evaluation of constituents that could occur at concentrations above the water quality criteria (i.e., concentrations are not considered to be conclusive or to represent actual predictions of water quality). SPLP testing is being conducted on 23 composite samples representative of the main Kings Mountain material types in Table 4-1. In addition to SPLP testing, these composites have also been submitted for LEAF testing as described in Section 4.2.2 below. Composite samples were generated from the core samples to capture the range of static test results (ABA and NAG) for each of the main material types. The sub -samples selected for each of the composites contain similar sulfide sulfur content and demonstrate similar ABA and NAG characteristics. For example, four composites were generated for the Amphibolite Gneiss -Schist material as shown in Figure 4-2 through 4-5. Also shown are the discrete samples selected for kinetic testing as described in Section 4.2.3. Graphs showing the sub -samples included in the composites for the remaining material types are provided in Attachment 1. Composites were not generated for the overburden (alluvium), granite or diabase material types because these material types comprise an insignificant portion (<1.5%) of the waste rock material. SPLP extracts were submitted for the list of analytes and associated reporting/detection limits in Table 4-4. Radiochemistry was not completed for one sample of pegmatite due to limited sample material. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 16 Kings Mountain Geochemical Characterization Work Plan Technical Memo NP vs. AP 1000 Non-PAG 100 O . ' - cn 8 ♦ 000 Amphibole Gneiss -Schist g O - 004-•' ---- NPR =1 NPR =2 U 10 $ O O ® O HCis m �e O O 8 O O O Comp 1* z O Comp 2 O Comp PAG O Comp 4 1 ' Selected for EPA 1314 0.1 0.10 1.00 10.00 100.00 AP (kg CaCO3/t) Figure 4-2: Neutralization Potential versus Acidification Potential NAG pH vs. NPR 12 11 N r.- •♦-���4♦o 10 r' OO O O O 00 O 0 9 cc CL Z O O O 00 0 0 8 00 lia— O O o ♦ Amphibole Gneiss -Schist 2 0 O O 0 00 NPR=2 x o 0 1 0 - - NAG pH=4.5 a 6 * * # O HCTs z g o A O Comp 1* 5 NAG pH = 4.5 O Comp 2 * O Comp 4 Q' O O Comp 4 3 � o * Selected for EPA 1314 2 1 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure 4-3: Neutralization Potential Ratio versus NAG pH SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 17 Kings Mountain Geochemical Characterization Work Plan Technical Memo NAG vs. NAG pH 60 PAG 1 Non-PAG 50 1 1 0 1 <, 40 1 O `^ x 1 co c 1 30 12 c � 1 v C7 1 a Q 20 1 w 1 z • 10 1 I •• �� i� o �Y �i B �•rr� �• •� ■ulllijb 0 2 4 6 8 10 12 NAG pH (s.u.) Figure 4-4: NAG pH versus Net Acid Generation NAG pH vs. Sulfide (wt %) 12 11 • ♦ ♦ �• i 10 9 ♦ ♦ ♦♦ 8 7 ?: ♦ O a 6 i . . ♦ . O❑♦ Z 7 Q Z ♦ ❑♦ 5 AG pH = 4.5 ----------- �♦�-♦♦------------ 4 ❑♦ Epic * 3 ♦ 2 1 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure 4-5: Sulfide Sulfur versus NAG pH • Amphibole Gneiss -Schist O HCTs — — NAG pH=4.5 O Comp 1 O Comp 2 O Comp 3 O Comp 4 Selected for EPA 1314 ♦ Amphibole Gneiss -Schist O HCTs — — NAG pH = 4.5 O Comp * O Comp2 * O Comp3 O Comp4 * Selected for EPA 1314 SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 18 Kings Mountain Geochemical Characterization Work Plan Technical Memo Table 4-4: List of Analytes and Detection Limits for Leach Tests Parameter Parameter Description Laboratory Method Laboratory Detection Limit pH Hydrogen ion concentration M9045D/M9040C - Conductivity Electrical conductivity SM2510B 2 pmhos/cm Alkalinity as CaCO3 General inorganic SM2320B - Titration 2 mg/L Bicarbonate as CaCO3 General inorganic SM2320B - Titration 2 mg/L Carbonate as CaCO3 General inorganic SM2320B - Titration 2 mg/L Hydroxide as CaCO3 General inorganic SM2320B - Titration 2 mg/L Aluminum Dissolved metals, filtered in lab M6010D ICP 0.05 mg/L Antimony Dissolved metals (filtered in lab) M6020B ICP-MS 0.0004 mg/L Arsenic Dissolved metals (filtered in lab) M6020B ICP-MS 0.0002 mg/L Barium Dissolved metals (filtered in lab) M6010D ICP 0.009 mg/L Beryllium Dissolved metals (filtered in lab) M6020B ICP-MS 0.00008 mg/L Bismuth Dissolved metals, filtered in lab M6010D ICP 0.04 mg/L Boron Dissolved metals, filtered in lab M6010D ICP 0.03 mg/L Cadmium Dissolved metals, filtered in lab M6020B ICP-MS 0.00005 mg/L Calcium Dissolved metals, filtered in lab M6010D ICP 0.1 mg/L Carbon, total General inorganic SM5310B 1 mg/L Carbon, total inorganic General inorganic SM5310B 1 mg/L Carbon, total organic General inorganic SM5310B 1 mg/L Chloride General inorganic SM4500CI-E 1 mg/L Chromium Dissolved metals, filtered in lab M6010D ICP 0.02 mg/L Cobalt Dissolved metals, filtered in lab M6010D ICP 0.02 mg/L Copper Dissolved metals, filtered in lab M6010D ICP 0.01 mg/L Fluoride General inorganic SM4500E-C 0.15 mg/L Gross alpha & beta, total Radiochemistry WG551392 2 to 4 pCi/L Iron Dissolved metals (filtered in lab) M6010D ICP 0.06 mg/L Lead Dissolved metals (filtered in lab) M6020B ICP-MS 0.0001 mg/L Lithium Dissolved metals, filtered in lab M6010D ICP 0.008 mg/L Magnesium Dissolved metals, filtered in lab M6010D ICP 0.2 mg/L Manganese Dissolved metals, filtered in lab M6010D ICP 0.01 mg/L Mercury Dissolved metals (filtered in lab) M1631E, Atomic Fluorescence 0.0000003 mg/L Molybdenum Dissolved metals, filtered in lab M6010D ICP 0.02 mg/L Nickel Dissolved metals, filtered in lab M6010D ICP 0.008 mg/L Nitrate/Nitrite as N General inorganic M353.2 0.02 mg/L Phosphorus Dissolved metals, filtered in lab M6010D ICP 0.1 mg/L Potassium Dissolved metals, filtered in lab M6010D ICP 0.2 mg/L Radium 226 + alpha emitting radium isotopes WG551336 WG551336 1 pCi.L Radium 228, total Radiochemistry WG551336 1.5 pCi/L Scandium Dissolved metals, filtered in lab M6010D ICP 0.05 mg/L Selenium Dissolved metals (filtered in lab) M6020B ICP-MS 0.0001 mg/L Silicon Dissolved metals, filtered in lab M6010D ICP 0.1 mg/L Silver Dissolved metals (filtered in lab) M6010D ICP 0.01 mg/L Sodium Dissolved metals, filtered in lab M6010D ICP 0.2 mg/L Strontium Dissolved metals, filtered in lab M6010D ICP 0.009 mg/L Sulfate General inorganic D516--07 - TURBIDIMETRIC 1 mg/L Sulfur Dissolved metals, filtered in lab M6010D ICP 0.25 mg/L Thallium Dissolved metals (filtered in lab) M6020B ICP-MS 0.0001 mg/L Thorium Dissolved metals (filtered in lab) M6020B ICP-MS 0.001 mg/L Tin Dissolved metals, filtered in lab M6010D ICP 0.04 mg/L Titanium Dissolved metals, filtered in lab M6010D ICP 0.005 mg/L Total dissolved solids General inorganic SM2540C 20 mg/L Uranium Dissolved metals (filtered in lab) M6020B ICP-MS 0.0001 mg/L Vanadium Dissolved metals, filtered in lab M6010D ICP 0.01 mg/L Zinc Dissolved metals (filtered in lab) M6010D ICP 0.02 mq/L SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 19 Kings Mountain Geochemical Characterization Work Plan Technical Memo Environmental Assessment Framework (LEAF) Testing The Leaching Environmental Assessment Framework (LEAF) is a leaching evaluation protocol that consists of four leaching methods, data management tools, and scenario assessment approaches designed to work individually or to be integrated to provide a description of the release of inorganic constituents of potential concern (COPCs) for a wide range of solid materials (US, EPA, 2022). The LEAF methods were originally developed in the European Union (EU) for evaluating coal combustion products and are designed to consider the effect of key environmental conditions and waste properties on leaching. The application of LEAF methods to mining evaluations is relatively new, but they are typically used when conventional static and kinetic test methods do not adequately describe potential chemical releases. To date, they have primarily been used in the assessment of constituent leaching from cemented backfill in underground mines (Schafer, 2016). For the Kings Mountain characterization program, the LEAF tests are being done to provide additional information on the leachability of the waste rock and ore material and provide the most comprehensive characterization of this material as possible. Each of the following leach tests is designed to vary a critical release -controlling parameter to provide leaching data over a range of test conditions: Method 1313: Liquid -Solid Partitioning as a Function of Eluate pH Using a Parallel Batch Extraction Procedure (US EPA, 2012a) Method 1314: Liquid -Solid Partitioning as a Function of Liquid -to -Solid Ratio Using an Up -Flow Percolation Column Procedure (US EPA, 2017a) Method 1315: Mass Transfer Rates in Monolithic and Compacted Granular Materials Using a Semi -dynamic Tank Leaching Procedure (US EPA, 2017b) Method 1316: Liquid -Solid Partitioning as a Function of Liquid -to -Solid Ratio Using a Parallel Batch Extraction Procedure (US EPA, 2012b) Three of these LEAF methods are proposed as being applicable for the Kings Mountain waste rock and ore geochemical characterization program these are; EPA 1313, EPA 1314 and EPA 1316. The EPA 1313 method is designed to evaluate the partitioning of constituents between liquid and solid phases at or near equilibrium conditions over a wide range of pH values (pH 2 to 12). The method consists of a series of parallel batch extractions of solid material at various target pH values, achieved with an aliquot of either dilute acid or base. Testing is undertaken on a pulverized sample at a fixed L/S ratio and produces a liquid -solid portioning curve of constituents as a function of pH. The EPA 1314 method is a column percolation test designed to evaluate constituent release from solid materials as a function of cumulative liquid -to -solid ratios (L/S). The method provides an estimate of porewater concentrations at low L/S and allows determination of the changes in liquid -solid partitioning as soluble constituents are released during successive pore volumes. The method is applicable to low oxygen conditions where rock is submerged, for example pit backfill. The EPA 1316 method is an equilibrium -based leaching test intended to provide eluate solutions as a function of the L/S ratio. This method consists of five parallel batch extractions in reagent water over a SRK CONSULTING (U.S.), INC. ■ DECEMBER 13, 2022 20 Kings Mountain Geochemical Characterization Work Plan Technical Memo range of liquid -to -solid ratios (2:1, 5:1, 10:1, 50:1 and 100:1). The method provides liquid -solid partitioning at the natural pH of a solid material as a function of L/S. LEAF testing using the EPA 1313 and 1316 methods are being conducted on the 23 composite samples that represent the range of geochemical variability demonstrated by the main Kings Mountain material types. These are the same composites used in the SPLP test described above. Graphs showing the sub -samples included in the 23 composite samples are provided in Attachment 1. Composites were not generated for the overburden (alluvium), granite or diabase material types because these material types comprise an insignificant portion (<1.5%) of the waste rock material. In addition, nine of the composites and one sample from the HCT program were selected for the EPA 1314 test to represent waste rock materials that would be submerged in the pit backfill after dewatering stops and groundwater recovers. The composites and HCT sample selected for EPA 1314 are shown in the figures provided in Attachment 1 and include: Composite 1 - Amphibole Gneiss -Schist Composite 2 - Amphibole Gneiss -Schist Composite 1 - Biotite Gneiss Composite 1 - Mica Schist Composite 2 - Mica Schist Composite 1 - Po Mica Schist Composite 1 - Shear Schist Composite 2 - Shear Schist Composite 1 - Upper Mica Schist HCT - Silica Mica Schist The EPA 1313, 1314 and 1316 methods have been selected for this study because they are considered the most applicable batch leach methods to assess constituent release from waste rock under the environmental conditions of the site. The EPA 1315 method is not considered applicable to this study because it is designed to assess leaching from monolithic materials (e.g., concrete or cemented rock fill) rather than heterogeneous waste rock materials. The selected list analytes and associated reporting/detection limits for the LEAF tests are the same as used for the SPLP test as summarized in Table 4-4. The exception to this is that the radiochemistry for the LEAF tests is limited to Gross Alpha and Beta. The extracts were not submitted for the full suite of radiochemistry because of limited sample volume generated by the LEAF test. However, the full suite of radiochemistry is being completed on the SPLP extracts. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 21 Kings Mountain Geochemical Characterization Work Plan Technical Memo 4.2.3 Kinetic Testing Kinetic testing is recommended for the Kings Mountain Project in order to assess the long-term weathering rates of sulfide and other metal bearing minerals, consumption of inherent neutralizing capacity and to determine potential metal and metalloid leaching rates, particularly for those material types that demonstrated an uncertain potential for acid generation in the static tests. Kinetic tests (e.g., laboratory humidity cell tests, "HCT's") evaluate temporal changes in leachate chemistry, through the sequential leaching of the rock in a regular cycle of exposure to dry and wet air in a controlled laboratory environment. These cycles simulate and accelerate the chemical weathering rates observed under field conditions, using test conditions that are specifically designed to target oxidation of sulfide minerals. The goal of kinetic testing is to provide reaction rate data to support prediction of the leachate chemistry that would likely develop during meteoric rinsing of waste rock storage facilities. Kinetic test data can also be used to predict concentrations of constituents that would be released from pit wall rock in response to meteoric rinsing and to develop a prediction of future pit lake water quality required for permitting of the project. The kinetic testing procedure selected for the Kings Mountain Project consists of the standard HCT procedure designed to simulate water -rock interactions in order to predict the rate of sulfide mineral oxidation and therefore acid generation and metals mobility (ASTM D5744-13e1) (ASTM, 2013). Under ASTM methodology, the test is carried out on material sized to pass a 6.3mm (0.25 inch) Tyler screen. The test follows a seven-day cycle during which air that is humidified and at a temperature of 250C is introduced at the bottom of the column for three days of each cycle followed by three days of dry air. On the seventh day, the sample is rinsed with distilled water and the extracted solution is collected for analysis. Key parameters including pH, alkalinity, acidity, electrical conductivity, iron and sulfate are measured on a weekly basis to provide intermediate reference points between full analyses that are conducted less frequently. Analysis of major and trace element chemistry is carried out on a weekly basis for the first four weeks of the test, after which the frequency of analysis is reduced to every fourth week. The selected list analytes and associated reporting/detection limits for the HCTs are the same as used for the SPLP test as summarized in Table 4-4. Due to the limited sample volume generated during the HCT, radium 228 and radium 226 + alpha emitting radium isotopes are being analyzed on composite samples. A 100 mL split is collected every week over an eight -week period to provide the sample volume needed for radiochemistry analysis.. Geochemical reactions and reaction rates monitored throughout the test include sulfide oxidation, depletion of NP, secondary mineral precipitation, adsorption -desorption reactions and mineral dissolution (INAP, 2014). Termination of the HCTs will be determined when the release rates of key constituents such as pH, sulfate, acidity, alkalinity and iron as well as dissolved metals and metalloids become relatively constant with time and there is no substantial change in the calculated release rate (INAP, 2014). Prior to termination of the HCTs, a memo summarizing the results and a request for approval to terminate the cells will be submitted to DEQ. This memo will provide the rational basis for termination and outline the methods proposed for termination testing. Humidity cells will not be terminated without DEQ approval. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 22 Kings Mountain Geochemical Characterization Work Plan Technical Memo Following termination of the leach portion of the HCTs, the material within the cells will be blended and split for termination testing. Termination testing will include multi -element analysis, ABA, NAG and mineralogical analysis on some of the test residues to define the mineralogical processes that occurred as the materials were exposed to oxygen and water and aid in the interpretation of the evolution of the leachate during the HCT. Results from the static geochemical characterization tests (ABA, NAG and multi -element) were used to select a sub -set of 22 samples representing the main waste rock and ore types for kinetic testing (Table 4-1). The geochemical properties of these material based on the static test results are illustrated in the scatter plots presented in Figure 4-6 through Figure 4-8. These graphs show the distribution of the samples selected for kinetic testing in relation to the entire dataset. Additional graphs are provided in Attachment 1 broken out for the main material types. These graphs show the samples selected for kinetic testing are representative of the range of static test results. Sulfide sulfur, NPR, NNP, NAG and NAG pH were the key parameters used for sample selection. Unlike the samples selected for SPLP and LEAF testing, the samples selected for the HCTs consist of a single sample selected from the static test program (i.e., are not composites of multiple samples). The exception to this is the HCT sample to represent pegmatite, for which limited material was available. For this HCT, a composite using two samples was generated to represent this material type. The resulting HCT sample set is lithologically representative of the deposit and the number of kinetic test samples selected for each material type is based on the relative importance or mass of the lithological unit with respect to the total mass in the deposit. Samples of granite and diabase material types were not selected for kinetic testing because these material types comprise an insignificant portion (<1 %) of the waste rock material. Even though alluvium represents a small portion of the mined waste rock (1.3%), a sample of this material type was selected for kinetic testing to provide source term chemistry for alluvium that will be needed for the pit lake geochemical modeling. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 23 Kings Mountain Geochemical Characterization Work Plan Technical Memo 140 120 100 c, v O 80 u m u s 60 a Z 40 m 20 0 0 0 c 0 0 -20 v -40 Z Z -60 -80 -100 0.01 NPR vs NNP 0.1 1 10 Neutralizing Potential Ratio (NPR) ■ Overburden Non-PAG O *Amphibole Gneiss - Schist ♦ Biotite Gneiss A Mica Schist ♦ Upper Mica Schist x A Po Mica Schist ♦ Shear Schist ♦Shear Schist 1 • Silica Mica Schist • Pegmatite •Spod Pegmatite +Granite X Diabase O HCTs 100 1000 Figure 4-6: Waste Rock and Ore Neutralizing Potential Ratio vs. Net Neutralizing Potential N P vs. AP 1000 Non-PAG ■ Overburden a a O Amphibole Gneiss -Schist Ou 100 O u O O O Uncn Biotite Gneiss X Mica Schist ♦ Upper Mica Schist O n BX 8 _ p Po Mica Schist v 10 O O �,l>.' O n� ♦ Shear Schist p■ OT ao • i Md C : .. v �� • Silica Mica Schist to • - • N �f m t • ,• p • Pegmatite 7i 0 ❑ V • Spod Pegmatite 0 w 1 .•❑, + Granite Z X Diabase PAG - NPR = 1 ---- NPR =2 0 0 HCTs 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCo3 eq/t) Figure 4-7: Waste Rock and Ore Acid Generating Potential vs. Neutralizing Potential SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 24 Kings Mountain Geochemical Characterization Work Plan Technical Memo NAG vs. NAG pH 60 A 1 ■ Overburden PAG 1 • Amphibole Gneiss -Schist 1 50 1 ♦ Biotite Gneiss 1 0 A Mica Schist O A A 1 ♦ Upper Mica Schist 40 1 2 1 0 Po Mica Schist s Non-PAG 0 0 1 ♦ Shear Schist 1 30 c A 1 • Silica Mica Schist w t7 0 1 • 1 • Pegmatite d 20 Z 1 1 • Spod Pegmatite 1 • + Granite Aa, Q � QQ 1 •�•i X Diabase 10 1 ��\ 1 • • Q — — HCTs NAG pH=4.5 ®�• — lJ • D 0 2 4 6 8 10 12 NAG pH (s.u.) Figure 4-8: Waste Rock and Ore NAG pH vs. Net Acid Generation 4.2.4 Mineralogy Samples selected for kinetic testing have also been submitted for mineralogical analysis, including optical microscopy, XRD and SEM analysis. A split was taken from the composites generated for the SPLP and LEAP testing for XRD analysis to aid in the interpretation of the leach test results. The purpose of the mineralogical analysis is to identify site -specific mineralogical characteristics that influence ARDML. This includes the identification of any sulfide minerals that are present and an assessment of how their grain size and mineral form will affect future weathering behavior. For example, whether the sulfides are liberated (i.e., available for reaction) or encapsulated in unreactive silicate minerals, and therefore unlikely to react. The mineralogical analysis also aims to identify any minerals that will provide neutralizing capacity and to determine their availability for reaction. Mineralogy is the key to interpreting results from the static and kinetic tests and may be used in conjunction with the other test results to assess likely long-term weathering behavior. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 25 Kings Mountain Geochemical Characterization Work Plan Technical Memo 5 Tailings Characterization 5.1 Tailings Sample Collection Samples representative of future tailings material have been sourced from various metallurgical test programs for geochemical characterization testing. This includes six samples from the 2018 pilot plant and 20 samples from the 2022 North Met program as summarized in Table 5-1. As described above, the metallurgical process is still under development; however, a preliminary process flow sheet is provided in Figure 5-1 that shows the points in the process at which the North Met program samples summarized in were collected. Although subject to change, the current plan is for ore from the pit to be crushed and ground to -850 pm and sent through a heavy liquid separation process that produces the DMS tailings. Remaining ore will be ground to -300 pm for further processing. Several waste streams will be generated during the flotation process that will be combined and co -disposed in the TSF as shown in Figure 5-1. The DMS tailings are proposed to be co -mingled with the waste rock and deposited in the waste rock dumps and the fine flotation tailings will be filtered and dry stacked in the TSF. As shown in Figure 5-1, a preconcentration step (i.e., ore sorting) will likely be included in the process. Rejects from the ore sorting process will be comingled with the waste rock and placed on the waste rock dump. Materials generated from this process are available from the North Met program and have been included in the characterization program. Albemarle is also currently evaluating the magnetic separation at various points in the process that may be included in the process flow sheet as shown in Figure 5-1. However, at this stage, material representative of the rejects from the magnetic separation are not available. Material from the magnetic separation process will be comingled with the waste rock and placed on the waste rock dump. As part of the 2022 North Met program, testing has been done on two master composites both with and without preconcentration. Variability composites were also included in this test program to capture the range of ore properties. In addition, process solutions from the metallurgical testwork were submitted for the analytes in Table 4-4. Various waste streams from the 2018 pilot plant study were also included in the characterization program including rejects from the magnetic separation, which are not available from the North Met program. However, the flow sheet for the 2018 pilot plant was slightly different from the 2022 North Met program and did not include ore sorting. In addition to the metallurgical test residues, approximately 10 to 20 additional samples of legacy tailings will be collected during the ongoing drilling program. Porewater within the tailings will also be sampled to provide an assessment of constituent leaching under field conditions. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 26 Kings Mountain Geochemical Characterization Work Plan Technical Memo Table 5-1: Solid Tailings Samples and Selected Test Methods Metallurgy Ore Location Sample Name ABA, SPLP LEAF HCT Program Sorting on Flow NAG, ICP (EPA (EPA Sheet 1312) 1313 and (Figure 5-1) 1316) NorthMet No Ore 1 Comp 1 DMS Tailings X X Program Sorting Comp 2 DMS Tailings X X 2 Comp1 Float Tailing X X Comp 2 Float Tailing X X Ore 3 Sorted Comp 1 DMS Tails X X X Sorting Sorted Comp 2 DMS Tails X X X Sorted Var 1 DMS Tails X Sorted Var 2 DMS Tails X Sorted Var 3 DMS Tails X Sorted Var 4 DMS Tails X 4 Sorted Var 1 Ore Sorting Float Tails X X' X' Sorted Var 2 Ore Sorting Float Tails X X' X' Sorted Var 3 Ore Sorting Float Tails X X' X' Sorted Var 4 Ore Sorting Float Tails X X' X' 5 Sorted Comp1 Ore Sorting Rejects X X X X Sorted Comp 2 Ore Sorting Rejects X X X X Sorted Var 1 Ore Sorting Rejects X Sorted Var 2 Ore Sorting Rejects X Sorted Var 3 Ore Sorting Rejects X Sorted Var 4 Ore Sorting Rejects X 6 Mag concentrate X 2018 Pilot No Ore NA DMS 1st Pass X X Plant Sorting Locked -Cycle Tests X X Floatation Tails X X Magnetic Separation (+6M) X Magnetic Separation (-6M/+32M) X Blended Fines/Middlings X Note: 'Composite of Sorted Variability Ore Sorting Float Tails (1 through 4) SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 27 Kings Mountain Geochemical Characterization Work Plan Technical Memo F°rocu�i Process Crushing Mine Rock & Grinding No Ore 6M5 HI Coarse DMS I Concentrate Grinding Desliming Mica Floatation Spodumene Flotation Spodumene Concentrate re Sorting 3: DMS Tailings 6: Magn 5: one Sorting Concentrate Reject Coarser Magnetic Srparanon a Coarse DMS Co n[entrate Ore Sorting No Mag Sep Figure 5-1: Process Flow Sheet for the NorthMet Program Ore Sorting F�---� DMS — Coarse DMS I - Concentrate Fines SRK CONSULTING (U.S.), INC. - DECEMBER 13, 2022 28 Kings Mountain Geochemical Characterization Work Plan Technical Memo 5.2 Tailings Test Methods Test methods selected for the tailings sample are summarized in Table 5-1 and include: 1. Static characterization testing, including ABA, NAG and multi -element analysis 2. Short-term leaching testing, including SPLP, EPA 1313and 1316 methodologies and mineralogy 3. Kinetic testing, including HCTs, mineralogy and termination testing The methods selected for the tailings samples are identical to those being used for characterization of waste rock and ore samples described in Section 4.2. The only exception is the mineralogical analysis, which will comprise QEMSCAN and TIMA analysis being completed as part of the metallurgical test program. In addition, the tailings characterization program will not include the EPA 1314 LEAF method, as this is an up -flow column percolation method not considered applicable to a dry stack tailings facility. 6 Data Evaluation and Reporting SRK will use the results of the static and kinetic geochemical characterization testing to evaluate the potential for acid generation potential and metal leaching from waste rock, ore and tailings associated with the Project. The results will be incorporated into numerical models to predict future water quality associated with the mine facilities and pit lake. Water chemistry modeling allows for the quantitative assessment of environmental impacts associated with the project and allows for the development of appropriate engineering design for operation and closure of the mine facilities. Geochemical test results will be compared to potentially applicable regulatory standards in North Carolina to provide a context in which to understand and interpret the data. An interim characterization report will be prepared in 1 sc Quarter 2023 that provides a summary of the static test results including the short-term leach tests. In addition, this report will include preliminary kinetic test data; however, the HCT program will be ongoing at the time the report is prepared and conclusions will be preliminary. Upon completion of the kinetic test program, a comprehensive characterization report will be prepared that contains full details of the characterization program methodology and results. In addition, during the HCT program a series of memos will be prepared at key milestones to provide a summary of the kinetic test results and recommendations for termination of the cells that have stabilized and have meet the objectives of the test. The results of the numerical modeling will be provided under separate cover. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 29 Kings Mountain Geochemical Characterization Work Plan Technical Memo References ASTM, 2013a, ASTM D5744 - 13e1. Standard Test Method for Laboratory Weathering of Solid Materials Using a Humidity Cell. Bureau of Land Management (BLM), 2008 (updated 2013), Instruction Memorandum No. NV-2013-046, Nevada Bureau of Land Management Rock Characterization Resources and Water Analysis Guidance for Mining Activities. Updated September 19, 2013. Hanahan, J., 1985. The Foote Quarry, Kings Mountain, North Carolina: Revisited, 1984. Rocks & Minerals, 60(2), 76- 82. International Network for Acid Prevention (INAP), 2014. Global Acid Rock Drainage Guide (GARD Guide). http://www.gardquide.com/. Mason, B., 1966, Principles of geochemistry: New York, John Wiley, 329 p. MEND, 2009. Prediction Manual for Drainage Chemistry from Sulphidic Geologic Materials. MEND Report 1.20.1. December 2009. Merschat, A.J., Hatcher, R.D., Jr., Byars, H.E., and Gilliam, W.G., 2012. The Neoacadian orogenic core of the southern Appalachians: A geo-traverse through the migmatitic Inner Piedmont from the Brushy Mountains to Lincolnton, North Carolina. In: Eppes, M.C., and Bartholomew, M.J., eds., From the Blue Ridge to the Coastal Plan: Field Excursions in the Southeastern United States: Geological Society of America Field Guide 29, 2012, p. 171-217.Miller, S., Robertson, A., & Donohue, T. 1997. Advances in acid drainage prediction using the Net Acid Generation Test, Proceedings on the 4th International Conference on Acid Rock Drainage, Vancouver, BC, 533-549. Miller, S., Robertson, A., Donohue, T. 1997. Advances in Acid Drainage Prediction Using the Net Acid Generation Test, Proceedings on the 4th International Conference on Acid Rock Drainage, Vancouver, BC, p. 533-549. Sapsford, D.J., Bowell, R.J., Dey, M. and Williams, K.P., 2009, Humidity cell tests for the prediction of acid rock drainage. Minerals Engineering 22(1), pp25-36. Schafer, W., 2016. Geochemical Evaluation of Cemented Paste Tailings in a Flooded Underground Mine. Proceedings IMWA 2016, Freiberg/Germany. Drebenstedt, Carsten, Paul, Michael (eds.). Mining Meets Water — Conflicts and Solutions. Sobek, A.A, Schuller, W.A., Freeman, J.R., & Smith, R.M. 1978. Field and laboratory methods applicable to overburden and mine soils, EPA 600/2-78-054, 203. SRK, 2021. SEC Technical Report Summary, Initial Assessment, Kings Mountain, North Carolina. Dated December 31, 2021. US EPA, 1994. Method 1312. Synthetic Precipitation Leaching Procedure. Revision 0. September 1994. US EPA, 2012a. Method 1313. Liquid -Solid Partitioning as a Function of Extract pH using a Parallel Batch Extraction Procedure. Revision 0, October 2012 SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 30 Kings Mountain Geochemical Characterization Work Plan Technical Memo US EPA, 2012b. Method 1316. Liquid -Solid Partitioning as a Function of Liquid -Solid Ratio in Solid Materials using a Parallel Batch Procedure. Revision 0, October 2012 US EPA, 2017a. Method 1314. Liquid -Solid Partitioning as a Function of Liquid -Solid Ratio for Constituents in Solid Materials using an Up -Flow Percolation Column Procedure. Revision 1, July 2017. US EPA, 2017b. Method 1315: Mass Transfer Rates of Constituents in Monolithic or Compacted Granular Materials Using a Semi -Dynamic Tank Leaching Procedure, July 2017. US EPA, 2022. Leaching Environmental Assessment Framework (LEAF) Methods and Guidance. Leaching Environmental Assessment Framework (LEAF) Methods and Guidance I US EPA. Accessed November 7, 2022. Wilson, W.F and McKenzie, B.J., 1980. Mineral Collecting Sites in North Carolina. 250p. Geologic Survey North Carolina. SRK CONSULTING (U.S.), INC. DECEMBER 13, 2022 31 Attachment 1 Data Evaluation Graphs showing SPLP/LEAF Composites and HCT Samples 1000 NP vs. AP 1 10 100 Acid Generating Potential (AP) (kg CaCO3eq/t) Figure Al: Neutralization Potential versus Acidification Potential — Overburden 12 11 10 9 8 3 7 x n 6 z 5 NAG pH = 4.5 41 3 2 1 0.00 0.01 NAG pH vs. NPR 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A2: NAG pH versus NPR —Overburden ■ Overburden NPR=1 ---- NPR =2 O HCTs ■ Overburden NPR=2 NAG PH = 4.5 HCTs NAG vs. NAG pH 80 PAG 1 �0 1 1 1 0 60 1 0 1 0 '^ 1 s 50 1 Non-PAG C 1 0 m 40 1 d 1 c w l7 1 v Q 30 1 w 1 Z I 20 1 I 10 1 I 0 I ® ❑ ❑ ❑ 0 2 4 6 8 NAG pH (s.u.) Figure A3: NAG versus NAG pH — Overburden 12 11 10 9 8 2 x n Q 6 Z 5 4 3 m 0 NAG pH vs. Sulfide (wt %) ■ El 10 12 A NAG pH = 4.5 — — — — — — — — — — — — — — — — — — — — — — — — — — — — - 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A4: NAG pH versus Sulfide Sulfur — Overburden ■ Overburden O HCTs — — NAG pH=4.5 ■ Overburden p HCTs — NAG pH=4.5 NP vs. AP 1000 Z Non-PAG a w 00 100Oncri ♦ O . ' - $ o o0 00 � ♦ Amphibole Gneiss -Schist O Q Og O �4,• NPR=1 m O 10 v $ O ® --NPR =2 1 g p2a O HCTs O c 'N O Comp 1 * 'F O Comp 2 * Comp 3 a 1 Z O Comp 4 PAG * Selected for EPA 1314 0.1 W-' 0.10 1.00 10.00 100.00 Acid Generating Potential (AP) (kg CaCO3eq/t) Figure A5: Neutralization Potential versus Acidification Potential — Amphibole Gneiss -Schist 12 NAG pH vs. NPR O 11 O 00 10 p0 N 8 0 OOO ♦ ♦ 9 z 00 O J O 0 8 00 �7 Qoo OOOo Q6 6 <X> 0 0 B0 Z b O 5 800 NAG pH = 4.5 — — — — — — — O - 4 Q. �i O 3 O ♦ 2 1 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A6: NAG pH versus NPR —Amphibole Gneiss -Schist ♦ Amphibole Gneiss -Schist NPR = 2 NAG pH=4.5 O HCis O Comp 1 0 Comp 2 0 Comp 3 1 Comp 4 * Selected for EPA 1314 NAG vs. NAG pH 60 1 PAG 50 1 � 1 0 0 1 40 1 x Non-PAG 0 rs 30 — 1 `m 1 c w 0 1 (7 v _ 1 y 20 1 Z 1 • 1 1 •• 10 • 1 %13 • • 0 �www �w• www wnn 0 2 4 6 8 10 12 NAG pH (s.u.) Figure A7: NAG versus NAG pH —Amphibole Gneiss -Schist NAG pH vs. Sulfide (wt %) 12 • 11 10 — 9 • 2 • �� ♦ s 8 ♦ ♦ • 7 ♦ O • • O 6 ♦ ♦ • Z a 5 NAG pH = 4.5 — — — — — — — — — — — — - *+—♦i — M — — — — — — — — — — — 4 ♦♦ i • • ♦ Y♦ 3 � 2 1 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A8: NAG pH versus Sulfide Sulfur — Amphibole Gneiss -Schist • Amphibole Gneiss -Schist O HCTs — — NAG pH = 4.5 O Comp 1 O Comp 2 O Comp 3 G Comp 4 * Selected for EPA 1314 ♦ Amphibole Gneiss -Schist O HCTs — NAG pH 4.5 p Comp 1 0 Comp 2 O Comp 3 0 Comp 4 * Selected for EPA 1314 1000 0 LE 0.1 NP vs. AP Non-PAG ® ® }*- - ® � m 1 10 Acid Generating Potential (AP) (kg CaCO3 eq/t) Uncn 100 Figure A9: Neutralization Potential versus Acidification Potential — Biotite Gneiss NAG pH vs. NPR O N II oe O a Z O O O O NAG pH = 4.5 4 Q p�U O 3 Ov a O 2 1 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A10: NAG pH versus NPR — Biotite Gneiss ♦ Biotite Gneiss NPR = 1 ---- NPR =2 Q HCTs O Comp 1 p Comp 2 G Comp 3 * Selected for EPA 1314 ♦ Biotite Gneiss NPR=2 NAG pH = 4.5 O HCTs O Comp 1 to Comp 2 O Comp 3 * Selected for EPA 1314 NAG vs. NAG pH 80 PAG I 7o I 1 1 0 60 1 0 1 0 '^ 1 s 50 Non-PAG r 1 0 m 40 1 d 1 c v Q 30 1 w pppggq I Z l�tl I 20 K16dA 1 1 10 E@ I OO 1 0 ♦ ®®®® �I 0 2 4 6 8 10 12 NAG pH (s.u.) Figure A11: NAG versus NAG pH — Biotite Gneiss NAG pH vs. Sulfide (wt %) 12 11 10 9 8 7 ® O x O n 6 z O 5 NAG pH = 4.5 — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 4 O O O 3 0� 2 1 0.007 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure Al2: NAG pH versus Sulfide Sulfur — Biotite Gneiss ♦ Biotite Gneiss O HCTs — — NAG pH = 4.5 Comp 1 Comp 2 Comp 3 * Selected for EPA 1314 ♦ Biotite Gneiss O HCTs — NAG pH=4.5 O Comp 1 13 Comp 2 O Comp 3 * Selected for EPA 1314 NP vs. AP 1000 Z Non-PAG a w Uv 100 m - Uncn Y a Z m C 10 ° ° ® ❑ ° ❑❑ �' a N m Z 1 PAG 0.1 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCO3eq/t) Figure A13: Neutralization Potential versus Acidification Potential — Mica Schist 12 11 10 9 8 x a 6 z 5 NAG pH = 4. 4 3 2 1 0.00 0.01 NAG pH vs. NPR 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A14: NAG pH versus NPR — Mica Schist A Mica Schist NPR=1 ----NPR=2 O HCTs O Comp 1 D Comp 2 O Comp3 * Selected for EPA 1314 A Mica Schist NPR = 2 NAG pH = 4.5 C HCTs 0 Comp 1 - O Comp 2 * O Comp 3 * Selected for EPA 1314 NAG vs. NAG pH 60 1 PAG 50 1 � 0 1 Q 1 40 1 x ® Non-PAG 0 `m 30 1 C 1 �7 ® 1 v Q 1 y 20 1 Z 1 1 1 10 1 1 0 1 0 2 4 6 8 NAG pH (s.u.) Figure A15: NAG versus NAG pH — Mica Schist NAG pH vs. Sulfide (wt %) 12 11 10 9 8 N 7 QEp ® dp n 6 z 10 12 5 Q Q NAG pH = 4.5 — — — — — — — — — — — — — — — — — — — — — — — — — — — — Q 4 3 ®Q 2 1 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A16: NAG pH versus Sulfide Sulfur — Mica Schist A Mica Schist O HCTs — — NAG pH=4.5 0 Comp 1 0 Comp 2 0 Comp 3 * Selected for EPA 1314 A Mica Schist 0 HCis — NAG pH=4.5 0 Comp 1 * 0 Comp 2 * 0 Comp 3 * Selected for EPA 1314 NP vs. AP 1000 ♦ Upper Mica Schist NPR = 1 ---- NPR =2 O HCTs O Comp 1 * Selected for EPA 1314 0 w- 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCO3eq/t) Figure A17: Neutralization Potential versus Acidification Potential — Upper Mica Schist 12 11 10 9 8 x n 6 Z 5 NAG pH = 4.5 4 3 13 1 0.00 NAG pH vs. NPR 0.01 0.10 1.00 10.00 Neutralization Potential Ratio Figure A18: NAG pH versus NPR — Upper Mica Schist 100.00 1000.00 Upper Mica Schist -NPR =2 NAG pH = 4.5 0 HCTs 0 Comp * Selected for EPA 1314 NAG vs. NAG pH 60 1 PAG 50 1 � 0 1 0 1 40 x m 1 no 1 c 0 1 6 30 `m m 1 c 1 l7 1 v ¢ y 20 C3 1 1 Z ® 1 C1 10 1 ® 1 0 0 1 0 2 4 6 NAG pH (s.u.) Non-PAG Figure A19: NAG versus NAG pH — Upper Mica Schist 8 10 12 NAG pH vs. Sulfide (wt %) 12 11 10 9 8 x n 6 O Z 5 NAG pH = 4.5 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4 3 'm Im 2 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A20: NAG pH versus Sulfide Sulfur — Upper Mica Schist ♦ Upper Mica Schist C HCTs - NAG pH = 4.5 0 Comp 1 * Selected for EPA 1314 ♦ Upper Mica Schist 0 HCTs — NAG pH = 4.5 0 Comp * * Selected for EPA 1314 NP vs. AP 1000 Non-PAG a v 0 100 • U - Jncn a Z 0 10 y1 p v o Q ' c Z ® p m _ 3 " Z 1 PAG 0 69 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCO3 eq/t) Figure A21: Neutralization Potential versus Acidification Potential — Po Mica Schist 12 11 10 9 8 x n 6 z 5 NAG pH = 4.5 4 3 2 1 0.00 NAG pH vs. NPR 0.01 0.10 1.00 10.00 Neutralization Potential Ratio Figure A22: NAG pH versus NPR — Po Mica Schist 100.00 1000.00 A Po Mica Schist NPR = 1 ---- NPR =2 Q HCTs 13 Comp 1 p Comp 2 * Selected for EPA 1314 Po Mica Schist NPR=2 NAG pH=4.5 O HCTs G Comp 1 Comp 2 * Selected for EPA 1314 NAG vs. NAG pH 80 1 PAG 1 70 1 A 1 1 0 60 ® 1 0 1 0 'N 1 s 50 1 1 Non-PAG r 0 m 40 1 d 1 c w l7 1 v 30 �, 1 Q U w 1 Z „1 1 C� 20 1 n ZA 1 � 1 10 A 1 �A 0 1 ® 1 0 2 4 6 8 10 12 NAG pH (s.u.) Figure A23: NAG versus NAG pH — Po Mica Schist NAG pH vs. Sulfide (wt %) 12 11 10 9 8 x n 6 Z 5 NAG pH = 4.5 — — — — — — — — — — — — — — — — — — — — — — — — — — — — 4 — Q A 3 2 i 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A24: NAG pH versus Sulfide Sulfur — Po Mica Schist A Po Mica Schist Q HCTs — NAG pH = 4.5 G Comp 1 O Comp 2 * Selected for EPA 1314 A Po Mica Schist O HCTS — NAG pH = 4.5 O Comp Comp 2 * Selected for EPA 1314 NP vs. AP 1000 Z Non-PAG a w w 100 ❑♦ ❑♦ v o , - Uncn O 0 0 ♦ Shear Schist a o ? ❑� O NPR=1 ---- NPR=2 r 10 ,6 n p ADa e O HCTs a c Q Comp 1 N 'ra O Comp 2 Comp a 1 Z 1 Comp 4 PAG * Selected for EPA 1314 0.1 19 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCO3eq/t) Figure A2S: Neutralization Potential versus Acidification Potential — Shear Schist 12 11 10 9 8 x n 6 z 5 NAG pH = 4.5 4 3 2 1 0.00 0.01 NAG pH vs. NPR 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A26: NAG pH versus NPR — Shear Schist Shear Schist NPR =2 NAG pH = 4.5 O HCis O Comp 1 * O Comp 2 * O Comp 3 O Comp 4 * Selected for EPA 1314 NAG vs. NAG pH 60 1 PAG 50 1 � 1 0 0 1 40 1 x no m 1 c 1 0 m 30 1 `m 1 c w l7 4 1 v 0 Q 1 y 20 }{ 1 Z 4®S 1 1 10 • 1 1 0 n 0 2 4 6 NAG pH (s.u.) Figure A27: NAG versus NAG pH — Shear Schist Non-PAG n F nrlR V n l rl�l NAG pH vs. Sulfide (wt %) 12 11 • ❑♦ • 10 ❑� 0 ❑o • 9 8 vi 7 x n 6 z 5 NAG pH=4.5 ♦♦ — — — — — — — — — — — — — — — — — — — — — — — — — — — — 4 3 At Am AA A 1 -4 0.007 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A28: NAG pH versus Sulfide Sulfur — Shear Schist o Shear Schist O HCTs — — NAG pH=4.5 O Comp 1 O Comp 2 O Comp 3 G Comp * Selected for EPA 1314 ♦ Shear Schist O HCTS — NAG pH-4.5 p Comp 1 * 0 Comp 2 * 0 Comp 3 13 Comp 4 * Selected for EPA 1314 NP vs. AP 1000 • Silica Mica Schist NPR = 1 ---- NPR =2 Q HCTs * * Selected for EPA 1314 0 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCO3eq/t) Figure A29: Neutralization Potential versus Acidification Potential —Silica Mica Schist 12 11 10 9 8 x n 6 z 5 4 3 2 1 0.001 NAG pH = 4.5 0.01 NAG pH vs. NPR 0.1 1 10 100 Neutralization Potential Ratio Figure A30: NAG pH versus NPR — Silica Mica Schist 1000 • Silica Mica Schist NPR =2 NAG PH = 4.5 0 HCTs * * Selected for EPA 1314 80 70 c 60 O = 50 no s c 0 f6 40 d c w (7 v Q 30 w Z 20 10 0 0 2 NAG vs. NAG pH PAG 1 1 1 1 4 6 8 10 12 NAG pH (s.u.) Figure A31: NAG versus NAG pH — Silica Mica Schist NAG pH vs. Sulfide (wt %) 12 11 • 10 9 • 8 O • 7 • n • 6 • z 5 NAG pH = 4.5 4 3 2 1 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A32: NAG pH versus Sulfide Sulfur — Silica Mica Schist • Silica Mica Schist O HCTs * — — NAG pH = 4.5 * Selected for EPA 1314 • Silica Mica Schist O HCTs — NAG pH = 4.5 * Selected for EPA 1314 NP vs. AP 1000 Non-PAG 6 N 100 • Uncn a • " Z C 10 o : • t• f. O • • • • • • a00 Z 1 PAG 0 — 0.1 1 10 100 Acid Generating Potential (AP) (kg CaCO3 eq/t) Figure A33: Neutralization Potential versus Acidification Potential — Pegmatite 12 11 10 9 8 x a 6 z 5 NAG pH = 4. 4 3 2 1 0.00 0.01 NAG pH vs. NPR 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A34: NAG pH versus NPR — Pegmatite • Pegmatite O Comp 1 O Comp 2 O Comp 3 Q HCTs NPR =1 ---- NPR =2 • Pegmatite O Comp 1 O Comp 2 O Comp 3 O HCTs NAG pH=4.5 NPR = 2 NAG vs. NAG pH 80 1 PAG 1 �0 1 1 1 0 60 1 0 1 0 '^ 1 s 50 1 Non-PAG C 1 0 40 1 d 1 c w l7 1 v Q 30 1 w 1 z 1 20 1 1 � 1 woo 10 1 0 ! oil •! 0 2 4 6 8 NAG pH (s.u.) Figure A35: NAG versus NAG pH — Pegmatite 12 11 10 9 8 x n Q 6 z 5 4 3 2 1 0.007 NAG pH vs. Sulfide (wt %) • 0.01 0.1 Sulfide Sulfur (wt %) Figure A36: NAG pH versus Sulfide Sulfur — Pegmatite 10 12 NAG pH = 4.5 1 10 • Pegmatite O Comp 1 O Comp 2 O Comp 3 Q HCTs — — NAG pH = 4.5 • Pegmatite O Comp 1 a Comp 2 a Comp 3 O HCTs — NAG pH=4.5 NP vs. AP 1000 Non-PAG 6 N O0 100 ' V incn Y a Z f6 Q • C 10 otw = • a • • �- ,E 3 w 1 Z 0 k� 0.10 / PAG 1.00 10.00 100.00 Acid Generating Potential (AP) (kg CaCO3 eq/t) • Spod Pegmatite O Comp 1 O Comp 2 0 HCTs NPR = 1 ---- NPR =2 Figure A37: Neutralization Potential versus Acidification Potential — Spodumene Pegmatite 12 NAG pH vs. NPR 11 • 10 • N I 9 Z 8 v 7 • • x • o- • 6 • z • 5 • NAG pH = 4.5 — — — — — — — — — — — — — — — • — — — — — — — — — — - 4 3 • 2 1 0.00 0.01 0.10 1.00 10.00 100.00 1000.00 Neutralization Potential Ratio Figure A38: NAG pH versus NPR — Spodumene Pegmatite • Spod Pegmatite O Comp O Comp O HCTs NAG PH = 4.5 NPR = 2 80 70 c 60 O = 50 no r 0 40 d w (7 v Q 30 w Z 20 10 0 • PAG NAG vs. NAG pH 1 1 1 1 1 Non-PAG 0 2 4 6 8 NAG pH (s.u.) Figure A39: NAG versus NAG pH — Spodumene Pegmatite NAG pH vs. Sulfide (wt %) 12 11 10 9 8 10 12 • Spod Pegmatite O Comp 1 O Comp 2 O HCTs — — NAG pH = 4.5 7 • Spod Pegmatite _ • O Comp n • L7 6 O Comp 2 z • O HCTs 5 • NAG pH = 4.5 — — NAG pH = 4.5 - - - - - - - - - - - • - - - - - - - - - - - - - - - - - 4 3 • 2 1 — 0.001 0.01 0.1 1 10 Sulfide Sulfur (wt %) Figure A40: NAG pH versus Sulfide Sulfur — Spodumene Pegmatite