Waste Rock Inclusions: A Co-disposal Method to Improve the Performance and Reduce the Risk of Tailings Impoundments
Symposium 2015 Rouyn-Noranda
Mr Michael James (Polytechnique Montréal)
Failures such as the ruptures of the Gullbridge Tailings Impoundment (2012) and the Mount Poulley Tailings Impoundment (2014) can have devastating effects on public safety, the environment or the public’s perception of the mining industry. Davies (2002) estimated that worldwide between 1970 and 2001 there were at least two major impoundment failures annually. The corresponding failure rate is ten times greater than that of water retention dams. It is in the best interests of the mining industry, and the public in general, to develop improved methods for the storage of wastes, particularly tailings.
Aubertin et al. (2002) hypothesized that waste rock could be placed in impoundments during deposition to form continuous inclusions of more rigid, more permeable material that would improve the geotechnical and environmental performance of the impoundments by providing drainage during tailings deposition and increased resistance to static and seismic loads. Research on waste rock inclusions has indicated that they can have very positive effects on impoundment performance and stability. This method is currently in use at a mine in the Abitibi region of Quebec. This paper summarizes the laboratory testing, numerical analyses, physical modelling, and field observations on the use of waste rock inclusions in impoundments.