Future Tailings Management

摘要

An average of about two tailings dam failures continue to occur each year, not all of which we hear about, as tailings volumes and dam heights, and hence risks, escalate. Particular focus of attention is on those that occur in developed countries (e.g. Mount Polley in Canada in 2014), or that involve global mining companies (e.g. at Samarco, jointly-owned by BHP Billiton and Vale, in Brazil in 2015). Tailings dam failures can cause loss of life and damage to infrastructure and the environment, a dramatic loss of trust in the company and the mining industry in general, an immediate and dramatic loss in shareholder value, and ongoing criminal and civil litigation. They raise questions about what should and must be done to clean up the impacts of the failures and to prevent future failures.Among the key questions to emerge are the following. What are the key drivers of tailings management? Is it a case of the human failing of continuing to do what we have always done? We continue to dispose of most tailings in slurry form, driven by net present value accounting, since slurry transport and disposal are the cheapest option in the short-term. Why do different regions of the world have different tailings containment practices? What is the risk of another tailings dam failure worldwide? The answer would have to be almost certain, including in developed countries and at mines operated by global mining companies! What are the responses to tailings dam failures? This paper goes some way to addressing these questions.