2012-10-01_REVISION - M1977310 (10)

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Acid -Base Accounting Results JD -6 -WRP JD- 8 -ROPCI JD- 8 -ROPC2 AVERAGE ORE Acid Potential (AGP) (t/kt) 2 4 7 5.5 Neutralization Potential (ANP) (t/kt) 53 61 71 66 Net Neutralizing Potential (NNP) (t/kt) 51 56 64 60 ANP /AGP ratio 26.5 15.3 10.1 12.7 Sulfur, HCl Extractable ( %) <0.01 0.04 0 08 0.06 Sulfur, HNO Extractable ( %) 0.05 0.10 0.13 0.115 Sulfur, Hot Water Extractable ( %) 0.02 0 68 0.64 0 66 Sulfur, Residual ( %) <0.01 <0.01 <0.01 0 01 Sulfur, Total ( %) 0.08 0.82 0.86 0.84 JD -6 Mine Environmental Protection Plan 9 The results of the ABA tests indicate that waste rock from the JD -6 underground mine has a net neutralizing (NNP) capacity of 51 t CaCO /kt and an ANP /AGP ratio of 26.5 (Table 5). Based on these results, the potential for material in the waste rock pile to generate acidic drainage is low. The results of the ABA tests indicate that ore from the nearby JD -8 Mine has an average net neutralizing (NNP) capacity of 66 t CaCO /kt and an average ANP /AGP ratio of 12.7 (Table 5). The NNP of the tested samples ranged from 56 to 64 t CaCO /kt while the ANP /AGP ratios ranged from 10.1 to 15.3. Based on these results, the potential for material in the ore storage pile to generate acidic drainage is low. The results of the February 2012 geochemical sampling of waste rock from the JD -6 Mine and the December 2010 geochemical sampling of ore from the nearby JD -8 Mine indicate that no materials classified as acid - forming exist on site. Table 5. Acid -Base Accounting (ABA) Results for Representative Composite Samples from the JD -6 Mine Waste Rock Pile and JD -8 Mine Ore Pile Notes: WRP = representative underground waste pile composite ROPC = representative ore pile composite 5.3.3.3 Whole Rock Elemental Analysis and SPLP Testing Results Geochemical testing performed on the composited samples also included whole rock elemental analysis and synthetic precipitation leaching procedure (SPLP) testing. Samples for whole rock elemental analysis were prepared using the cone - and - quarter method to generate 115- to 208 -gram splits (Table 4). The split samples were crushed in their entirety by Energy Laboratories and grab sample was taken from the pulverized blended sample for the analytical split. The samples were analyzed for 23 elements by inductively coupled plasma atomic emission spectrometry (ICP -AES) and mass spectrometry (ICP -MS). An initial nitric acid (HNO and hydrogen peroxide (H digestion (EPA method 3050B) was used to prepare samples for ICP -MS (EPA method 6020). ICP -AES analysis (EPA method 6010B) required the addition of hydrochloric acid (HC1) to the initial digestate (EPA method 3050B -M). EPA method 7471A, an aqua regia digestion with cold vapor atomic absorption spectrometry was used for mercury. Sulfur species were determined using the Sobek Modified method. Analytical results and laboratory reports for whole rock elemental analyses are presented in Table 6. Elemental data indicate that the ore and waste rock are enriched in arsenic, cadmium, lead, molybdenum, selenium, uranium, and vanadium compared to world shale averages and world sandstone averages (Rose et al., 1979). The ore and waste rock are deficient in aluminum, barium, boron, chromium, copper, and iron compared to world shale averages and world sandstone averages (Table 6). For most metals, abundance in the whole rock sample did not necessarily correlate with high leachate concentrations in the SPLP testing. The SPLP tests were performed by Energy Laboratories in accordance with EPA method 1312 (EPA, 1994) and consisted of leaching the samples in a solution of weakly acidified deionized water for 18 hours. The extraction fluid was prepared by titrating a 60/40 weight percent mixture of sulfuric and nitric acids to 4148A.120927 Whetstone Associates