Prediction and prevention of acidic drainage from mine wastes

Dr. David W. Blowes
Professor of Earth and Environmental Sciences at the University of Waterloo where he holds the Canada Research Chair in Groundwater Remediation.

The management of mine waste is a major challenge facing the mining industry throughout the world. When not managed effectively, mine wastes, including mill tailings and waste rock, can leach acidic water with high concentrations of metals that are harmful to the surrounding ecosystems. Mine wastes can be difficult to manage due to the large amounts of waste produced and the variability in the physical and chemical properties of the waste.

Acidic drainage results from the oxidation of sulfide minerals and the subsequent transport of oxidation products through the mine wastes. Current research has involved the investigation of geochemical, microbiological and mineralogical processes that control the rate and extent of sulfide oxidation and the physical water, gas and heat transport processes that are coupled to the chemical processes. These investigations range from micro-scale characterization to field-scale measurements of physical transport processes, and involve an array of techniques including synchrotron-based x-ray techniques to determine changes in mineralogy, multi-collector ICP-MS to measure the fractionation of metal isotopes, microbial DNA sequencing, automated field-based sampling networks, and numerical modelling techniques to integrate the large data sets.