Diavik Waste Rock Project: An Integrated Study of Waste Rock Evolution
Symposium 2015 Rouyn-Noranda
Mr David W.Blowes (University of Waterloo)
The Diavik Waste Rock Project, which was initiated in 2004, combines laboratory, field and modelling research components to characterize the physicochemical processes occurring in waste rock. Studies have been conducted on samples of waste rock of varying sizes, ranging from a few kilograms in laboratory experiments, 6 tonnes in 2 m scale experiments, 100,000 tonnes in each of three 60 × 60 x 15 m high experimental test piles, to >100 million tonnes in the operational waste-rock pile. Instrumentation placed in these field installations provides measurements of the thermal, gas transport, hydrological and geochemical systems. These measurements have been coupled with numerical modelling to provide an improved understanding of gas transport, permafrost formation, hydrology, and the biogeochemical process that affect effluent composition and the loadings of dissolved constituents. The results indicate strong coupling between physical and biogeochemical processes. This coupling results in solute release rates, and seasonal variations in effluent water quality, that strongly relate to the thermal regime within the test piles. These studies can be used to refine the closure plan for the Diavik waste dumps.