Economic feasibility and sensitivity analysis of integrating industrial-scale mineral carbonation into mining operations

Abstract

Proposed carbon reduction measures—such as cap-and-trade—appear poised to have a significant impact on the financial feasibility of mining operations as point-source emitters of carbon dioxide (CO2). It is therefore necessary to proactively assess the ways in which these effects may be mitigated. Carbon sequestration through mineral carbonation is well suited for integration into mining operations. Its ability to make use of waste rock to trap and store CO2, given suitable geological conditions, can help to significantly reduce carbon emissions. This paper presents the first attempt at conceptually integrating a high temperature and pressure industrial mineral carbonation facility into a developing minesite. The Turnagain nickel site, a low-grade, high-tonnage Ni-sulphide deposit, located in Northern BC, contains an abundant amount of Mg–silicate minerals in its waste rock. These minerals have significant potential for use in mineral carbonation. In the presence of a mandatory cap-and-trade scheme in North America, there is the potential to produce an additional revenue stream through the generation and sale of carbon credits. Results of financial modeling have yielded a net present value (NPV) at an 8% discount rate of $131.5million for the integration of mineral carbonation into proposed mining operations at Turnagain, suggesting that the project may be viable from a financial standpoint. Sensitivity analysis has also demonstrated that the parameter with the greatest influence on project NPV is the CO2 avoidance ratio. This ratio, which takes into consideration the amount of CO2 released in the mineral carbonation process to determine the net amount of CO2 avoided, is critical to maximizing the amount of carbon credits available for sale in a cap-and-trade environment.