Revaluing mine waste rock for carbon capture and storage

Abstract

Many mining wastes, especially those from the metal mining industry, have traditionally been treated as a matter of little or no value and in practice a cost burden. Some wastes, because of their reactivity characteristics, have emergent values that go beyond purely economic and into the environmentally beneficial realm. This article discusses the changing paradigm of mine waste management. Such fundamental parameters, such as cut-off grade and strip ratio, are positively impacted by the revaluation of waste rock material. Mine rock waste can now be seen as a commodity of value similar to the underlying ore being mined, which influences the economic performance of suitable projects. This valuable material can be used for industrial purposes including acid neutralisation as well as the capture and long-term disposal of anthropogenic carbon dioxide. The Turnagain Nickel project, located in Northern British Columbia, serves as an example of how waste rock material can become an important matrix for carbon capture and sequestration and how a project can benefit economically from it. By producing material that has emergent economic value as well as carbon capture and sequestration capabilities, the sequestration matrix producer is a beneficiary of new carbon credits that have a market value and is looked upon favourably by regulatory authorities and affected stakeholders.