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<br />J <br /> <br />- 2 9 - <br />4 CONCLUSIONS <br />1) The acid/base accounting and humidity cell techniques were gesaerally <br />accurate in predicting the formation of acid mine drainage for• selected <br />mines in British Columbia. A few results from the humidity cell, how- <br />ever, were difficult to interpret due to indefinite pH trends. The <br />humidity cell results were successful in assessing the potential for <br />acid mine drainage production for samples which exhibited a balance <br />between acid production potential and neutralization potential <br />according to acid/base accounting. <br />2) The lower humidity in the 1983 test cells reduced the pyrite oxidation <br />rate, particularly in samples with very high percent sulfur. In future <br />tests using the humidity cell technique, the input air should be satur- <br />~ ated with water vapour to ensure that humidity does not limit pyrite <br />oxidation. <br />3) The pyrite oxidation rates per unit mass of sulfur in the humidity cell <br />experiments were lower for samples with high percent sulfur compared to <br />low sulfur. This observation is only partially explained by the lower <br />humidity in the 1983 tests. Acid generation predictions based on the <br />percent sulfur content of a sample, such as acid/base accounting, may <br />be conservative for high sulfur containing rocks. However, since rocks <br />with high percent sulfur usually exhibit large negative neutralization <br />r potentials, this finding would not often affect the qualitative acid <br />mine drainage prediction. Further experiments with high percent sulfur <br />samples are recommended to confirm this finding. <br />4) The net neutralization potential found from acid base accounting gave a <br />fair estimate of whether acidity would be produced in the humidity <br />cells. In general, only samples with relatively high percent sulfur <br />G^ <br />