Grant: Alliance Grants

Tailings are the byproduct of grinding of rock or processing of soil generated by mining, physically resembling a wet mud, and produced in enormous quantities - for example, some of the tailings deposits in northern Alberta can be easily distinguished by the naked eye from the International Space Station, and the dams containing the tailings are among the largest earth structures in the world. Tailings deposits, unfortunately, have a record of dam failure, and, due to the wet and weak nature of the tailings, these dam failures has resulted in large flow slides, often travelling for 10's of kilometres, with devastating effect. One of the most recent notorious failures was in Brumadhino, Brazil, which killed 300 people in 2019. Canada's most well know recent Failure in the Mount Polley dam breach in 2014 in British Columbia, which fortunately did not incur human fatalities, but the tailings did flow into a large freshwater lake, important to the salmon fishery. The goal of this project is to develop criteria that engineers can use to judge the "flowability" of tailings. In other words, in the event of a breach, what is the likelihood of a long runout with catastrophic impacts? The project will reach this goal through physical experiments inducing failure of tailings deposits, at a variety of scales, the largest using a 6 m long 4m high 4 m tall existing test facility. Experiments will be conducted primarily at Carleton University and the University of Alberta, assisted by collaborators with key expertise from the University of Waterloo and the University of British Colombia. The research will be guided by an industry advisory committee, comprised of engineers who are actively working on reclaiming the oil sands tailings deposits.