2010-08-02_REVISION - M1977300 (28)

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Environmental Protection Plan, Schwartzwalder Mine 14-2 • Table 142. Average Mineral and Chemical Analyses of Schwartzwalder Rocks Lime-Silicate- Schwartzwalder Schwartzwalder Mica Schist Vein Material Hornblende Gneiss Trend Quartzite Trend Garnet- Biotite-Gneiss Calcite 15 nd nd nd nd Pyrite nd 5 4 nd nd Major Components (%) SiO2 43 94 54 61 Mgo 4 0.5 3 2 CaO 12 0.6 1.5 1.3 Total Iron 11 2 19 13 Total Carbon 2 0.3 1.4 0.4 5.4 Total Sulfur 0.1 0.3 1.4 0.01 0.7 Arsenic 18 25 14 2 73 Cadmium nd nd 2 nd 2 Copper 68 26 9 20 357 Molybdenum 11 6 15 4 1933 Nickel 59 5 40 3 47 Lead 9 nd 6 30 2267 Uranium 9 14 18 4 5100 Vanadium 20 11 19 78 313 Zinc 8 15 142 112 273 Metals (ppm) Note: nd = not detected The results of the whole rock analyses indicate that metals, including molybdenum, lead, and uranium are • enriched in the vein material above normal crustal abundances. Copper, vanadium and zinc are also enriched in vein material, but not to the extent observed for molybdenum, lead, and uranium. Metal concentrations in waste lithologies are lower than in the vein material, and although they are weakly elevated, the concentrations are near normal crustal abundances for igneous and metamorphic rocks as cited in Rose et al., 1979. (ii) Acid-Base Accounting Acid-base accounting (ABA) tests were used to evaluate the potential for waste rock and fill material to generate acid rock drainage. Eleven samples of waste rock were submitted for ABA testing including six samples from the West Waste Rock Pile and five samples from the East Waste Rock Pile. The samples were collected from five separate pits and most of the rock had been exposed to surface weathering conditions for at least ten years. Acid-base accounting provides a theoretical estimate of the net acid-producing potential of rock materials by comparing the total acid generating potential (AGP) to total acid neutralizing potential (ANP). Test results are generally evaluated by calculating the net neutralizing potential (NNP = ANP-AGP) or by the ratio of ANP to AGP (ANP/AGP). Samples with NNPs greater than 20 and ANP/AGP ratios greater than 3 are considered to have low potential to produce acid. Samples with NNP values between 0 and 20 and ANP/AGP ratios between 3 and 1 are indeterminate. Samples with negative NNP values and ANP/AGP ratios below 1 are potentially acid generating (EPA, 1994). The results of the ABA tests indicate that waste rock from the Schwartzwalder Mine is strongly neutralizing with an average net neutralizing (NNP) capacity of 149 t CaC03/kt and an ANP/AGP ratio of 10 (Table 14-3). The NNP of the tested samples varied from 86 to 206 t CaC03/kt. The observed range of t CaC03/kt ratios was 2.3 to 28.5. Only one of the samples tested had an ANP/AGP ratio less than 3. Its net neutralizing potential, however, was 89 t CaC03/kt which is more than four time greater than the - recommended guidance of 20 t CaC03/kt for material with low potential to produce acidic drainage. Based 4109C.100731 Whetstone Associates