| Summary: | The Net Acid Production Test (NAP) was developed as a hydrogen peroxide-based static test
for the prediction of acid rock drainage which could be applied in the field. Previous evaluation
indicated the test underestimated the Net Acid Production Potential of mine waste samples.
Recognizing that this error might have been the result of incomplete oxidation of iron sulphide
minerals in the mine waste, modifications to the test were introduced, primarily to enhance the
degree of oxidation. Ten mine waste samples were characterized (particle size, chemistry,
mineralogy) and subjected to the modified NAP test, standard Acid Base Accounting, Modified
Acid Base Accounting, and the B.C. Research Initial static tests. The results of the NAP test
were quantitatively comparable to those of the; other static tests. Comparison of the sulphur
content of four samples before and after the NAP Test indicated that 95 to 99 percent of the
sulphur initially present was oxidized by the hydrogen peroxide digestion. It was concluded that
the modification improved the extent of iron sulphide mineral oxidation and, consequently, the
accuracy of the test.
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