Practical Application of Accelerated Methods of Acid Rock 'Drainage and Metal Leaching Prediction of Mine Materials

摘要

Geochemical characterization studies are a continually evolving component of allstages of the life-cycle of mining projects. These studies are often used to predictthe acid rock drainage and metal leaching (ARD/ML) potential of mine materialsso that, ideally, environmentally protective management strategies can bedesigned and implemented throughout the life of the mine (LOM). Waterqualities for the LOM derived from these geochemical characterization studies,among other things, often form the basis for such environmental managementstrategies. If materials with a potential for acid generation are present at a mine site, LOMwater quality predictions usually need to include a component representative ofthe effects of acid generation from mine materials. However, geochemical teststypically utilized to provide this information (e.g. humidity cells) may requiremonths, or even years, in laboratory conditions prior to the realization of acidgenerating conditions. Therefore, alternate testing methods or the use of genericsurrogate data is often required to compliment the results of standard humiditycell testing. Accelerated geochemical testing is an alternate method for estimating theexpected long-term water quality from mine materials. A comparison withlong-term humidity cell tests to supernatant water qualities derived duringnet-acid generating (NAG) testing indicates this method can provide aconservative estimate of the expected long-term water quality based on laboratoryresults. In addition, accelerated humidity cell tests, which incorporate an initialdigestion of neutralization potential (NP) in a sample, can be used to determinethe water quality of a sample under acidic conditions. The current study presentspractical applications of these methods at three sites.