Closure cost refers to the total financial expenditure required to safely and responsibly decommission a mine, rehabilitate disturbed land, remediate environmental impacts, and fulfill all regulatory, social, and legal obligations at the end of a mine's productive life. Closure costs are a critical component of the overall life-of-mine financial model for bauxite, gold, iron ore, and diamond mining operations, and are increasingly scrutinized by regulators, investors, lenders, and communities. In bauxite mining, closure costs include the rehabilitation of mined-out areas through topsoil replacement, revegetation, and ecosystem restoration, as well as the stabilization and long-term management of bauxite residue storage areas (BRSAs). In gold mining, closure costs can be substantial due to the need to treat acid rock drainage (ARD) from sulfide waste rock, decommission tailings storage facilities (TSFs), remediate cyanide-affected areas, and monitor groundwater quality for decades post-closure. In iron ore mining, closure costs address large open pit void management, waste dump erosion control, and processing plant demolition. In diamond mining, closure costs include decommissioning of processing plants, rehabilitation of kimberlite open pits or underground workings, and long-term monitoring of tailings dams. Closure costs are typically estimated at various levels of engineering accuracy (order of magnitude, pre-feasibility, feasibility) and are updated regularly throughout the mine's life.
