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~ ~1 <br />above -20 kg CaCO,/t imply the sample will not :produce acidic drain,t,ge. These values are not <br />endorsed, but rather used as a tool for data pres~:ntation. <br />For ease of comparison with other tests; the APP deterrniniai by the NAP 'l'est was <br />expressed as the equivalent Net NP, using the relationship NAP Ned NP == -Net AP. This <br />conversion is rro1: entirely correct. The dissolution of acid-neutralizin„ mineras may br largely <br />limited by the amount of acid generated as a result of iron sulphidE: miner:il oxidatiim. If a <br />sample contains an excess of acid-neutralizing minerals, the faction of these minerals which do <br />not dissolve will not be accounted for. Thus, the NAP is subject to uncierestirnating the amount <br />of acid-neutralizing minerals present in samples ii which they aze pre:<.~ent in excess of the iron <br />sulphide minerals (i.e, samples with a high Net NP). No samples with elevated Net NP values <br />were tested in this study. <br />For quantitative comparison of NAP results with those from the other static tests, the <br />NAP Net NP was compared with the average values from the standard P~BA, Ivfodified ABA and <br />B. C. Initial Tests. This average is not recommended for mine waste evaluation and was used <br />only to simplify data presentation. <br />The Net NP was also calculated using the rr.ineralogical composition of the samples. The <br />capacity for acid production (mineralogical APP) was calculated based on the sulphur associated <br />with iron sulphide minerals, jazosite, and melanterite. The mineralogical NP was calculated as <br />the sum of calcium carbonate and magnesium carbonate content. [t. was assumed that the <br />calcium carbonate and magnesium carbonate present in the mine waste samples (Table 2), and <br />only these minerals, would neutralize acid and mairrtain pH above an environmentally acceptable <br />level of pH 6.0. The mineralogical Net NP w,ts calculated as the difference between the <br />mineralogic NP and mineralogic APP. <br />QUALITATIVE COMPARISON WITH OTHER STATIC TESTS <br />The acidic drainage predictions by the NAP Test were generally in good agreement with <br />the other static tests (Table 3). The NAP results agreed with all three of the other static test <br />methods on the acid producing character of eight of the samples (RK-1, B:IC-2, RK-3, RK-4, TL- <br />1, TL-4, TL-5, TL-6). Three of the samples for which agreement was universal (RK-1, RK-2, <br />TL-1) were classified as "inconclusive", based on Net NP (all tests) values of -14 to +18 kg <br />CaCO,/t. The remaining five samples for which agreement was universal (RK-3, RK-4, TL-4, <br />TL-5, TL-6) were classified as acid producing. The Net NP values (,ill tests) for these five <br />samples in the range of -147 to -39 kg CaCO,/t, with the exception of one value of -22 kg <br />CaCO,lt (B. C. Initial Net NP for RK3). The mineralogic Net NP values were in agreement <br />with the classification of all eight samples. <br />ISI <br />