Life of Mine (LOM) refers to the total estimated duration of a mining operation from the commencement of mineral extraction to the cessation of mining activities and the completion of mine closure and rehabilitation works. It is one of the most fundamental planning parameters in mining, providing the basis for long-term financial modeling, capital investment decisions, infrastructure sizing, workforce planning, environmental management, and community development strategies. Life of Mine estimates are derived from geological resource and reserve estimates, mine design parameters, planned production rates, and commodity price assumptions.
The LOM is typically expressed in years and is calculated by dividing the total proven and probable ore reserves accessible and economic to mine by the annual rate of ore extraction. For large open-cut bauxite mining operations in Australia, Guinea, or Brazil, the LOM may extend from thirty to over one hundred years given the vast laterite deposits involved. For underground gold mines with deep, high-grade but lower-volume ore bodies, the LOM may range from five to twenty years. Iron ore operations at Pilbara mega-mines in Western Australia have LOM projections extending well beyond fifty years. Diamond mines, such as kimberlite pipe operations, typically have LOM ranging from ten to forty years depending on pipe size and diamond grade.
The LOM plan is a dynamic document that is regularly updated as new geological information becomes available through ongoing drilling and resource estimation, as mining conditions change, and as commodity prices and operating costs are revised. A comprehensive LOM plan includes a mine schedule (sequencing of ore and waste extraction year by year), a processing schedule, capital expenditure profile, operating cost projections, environmental liability provisioning, and a mine closure and rehabilitation plan. The LOM has significant implications for community agreements, host government royalty and taxation arrangements, and long-term infrastructure investment by both mining companies and governments.