APPLICATION OF QUANTITATIVE MINERALOGY IN THE INTERPRETATION OF LABORATORY SCALE ACID ROCK DRAINAGE (ARD) PREDICTION TESTS: A GOLD CASE STUDY

摘要

In the move to practise sustainable mining, so there is an ever increasing awareness of the large volumes of waste generated by the industry and managing the risks associated with this material. In the context of acid rock drainage (ARD), reliable and accurate prediction is essential to the effective management of the long term risks. Typically ARD prediction entails the use of small scale geochemical tests with little consideration of the impact of the mineralogy of these ores, and of the benefit that can be achieved when mineralogy and geochemistry results are interpreted side by side. This study follows a mineral mass balancing approach on a gold ore in understanding the contribution of various minerals to laboratory scale acid base accounting (ABA) and net acid generation tests (NAG), as well as on the novel UCT biokinetic test. The results show the contribution of the carbonates to the acid neutralising capacity, as well as the varied contribution of the silicate minerals, likely through incongruent dissolution, from the different ANC test methodologies. The study also reinforces the potential of the novel UCT biokinetic test by demonstrating microbial leaching of similar minerals to conventional static ARD prediction tests.