Mine Waste

To a large extent, mining is a waste management business. In most mining operations, metal resources are found in host rocks at concentrations of a few percent or less, resulting in the production of large quantities of wastes during metal extraction and processing. These wastes can occur in the form of bulk waste rock, and fine-grained material (tailings) that remain after the ore is ground and processed. The two principal mine-waste management challenges are the containment of tailings, and the management of contamination leaching from tailings and waste rock. Over the past decade, several high-profile, catastrophic tailings-dam failures have led to a significant change in the way mine wastes are treated. New global standards have significantly improved industry tailing-management practices, with the potential to significantly reduce, if not eliminate, the environmental impacts of mine wastes. This essay reviews the complex problem of mine waste management, and discusses emerging new approaches—both technical and regulatory—to help ensure that mine waste storage facilities are safe from catastrophic failure, and non-polluting in perpetuity. More work is needed to ensure that these new approaches become cost-effective so that they can be widely adopted by the global mining sector.