Assessment of interpretation methods for kinetic tests performed on tailings having a low acid generating potential

摘要

This paper presents a comparison of 3 methods to assess the long term acid generationpotential (AGP) using the results from humidity cell tests performed on 5 tailingsclassified in or near the uncertainty zone for conventional static tests (-20 < NNP < +20 kgCaCO_3/t). The first method used is mentioned in the ASTM (2007)standard for humidity cell tests; the second one is based on the oxidation-neutralizationcurve; the third method relies on mineral depletion calculations using quantitative XRDanalysis and elemental tracers. The methods presented here involve relatively simplecalculations based on extrapolation of experimental results. The results from the threemethods indicate that 1 of the 5 tailings tested would be acid generating in the long term,while 3 tailings are non-acid generating and 1 tailings yielded contradictory results. TheASTM approach was found to be less conservative than the other methods to predict thelong-term acid generating potential. The oxidation-neutralization curve method seems tobe a promising predictive tool based on the results presented here.