Advances in Acid Rock Drainage: New approaches to Prevention and Remediation

Acid rock drainage (ARD) forms when pyrite is exposed to oxidation, and is a continuing problem at mine sites around the world, because of both its acidity and dissolved heavy metal content. Acid sulphate soils are a related aspect of the same problem. Much of the current focus is on prevention, by accurately assessing the acid-generating potential of mine waste and tailings. However, at many legacy sites, acid drainage continues to be generated and requires remediation (neutralisation); a large number of techniques have been developed for this.

This webinar will cover the basic concepts of acid rock drainage and its neutralisation, and discuss in detail some of the research that has been undertaken on this, particularly the advantages of concrete as a neutralising material, the possibility of extracting valuable metal sulphides during treatment, minimising the problems of armouring when using limestone, the difficulties of disposing of the sludge precipitated during ARD treatment, the possibility of modifying neutralisation to form a high density magnetic sludge, and encouraging the precipitation of secondary minerals (alunite) to decrease acidity release.