The Open Collections website will be undergoing maintenance on Wednesday December 7th from 9pm to 11pm PST. The site may be temporarily unavailable during this time.

British Columbia Mine Reclamation Symposium

Modification of the Net Acid Production (NAP) Test Lapakko, Kim; Lawrence, Richard W.


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.

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International