Evaluation of Geochemical Tests in Predicting Acid Mine Drainage Potential in Coal Surface Mine

Geochemical tests that are generally conducted to predict AMD potential have been studied using samples from a coal mine area in Kalimantan, Indonesia. Acid base accounting and net acid generation (NAG) tests were used to classify whether the samples were potentially acid forming or non acid forming material. A modified free draining column leach test was conducted on the potentially acid forming samples to understand the kinetics of acid generation. The results of more than 200 days of observation are presented in this paper. Both comparisons and findings were analyzed. There were some deviations between the result of acid base accounting analysis and the result of kinetic test. This study could be used to revisit the interpretation of test results for a better prediction on AMD potential in coal mines.