KGHM Polska Miedź has increased the Ore Reserve at its Sierra Gorda copper operation in Chile by 61%, extending the reserve-supported mine life to 2045 and underpinning a processing expansion that is expected to raise copper production from 2031. Sierra Gorda SCM is owned 55% by KGHM and 45% by South32. Its updated Ore Reserve now stands at approximately 1.10 billion tonnes grading 0.39% copper, 0.016% molybdenum and 0.06 g/t gold, equivalent to about 0.46% copper equivalent.
The operation’s Mineral Resource has also risen by approximately 8% to 1.87 billion tonnes. The updated estimates follow a major infill drilling programme comprising approximately 85,000 metres across around 200 holes. The drilling has increased geological confidence and enabled additional material to be incorporated into categories suitable for longer-term mine planning.
Fourth Grinding Line Supports Higher Throughput
The expanded resource and reserve base is being matched by additional processing capacity at Sierra Gorda. The operation is advancing a fourth grinding line that will increase nominal processing capacity from approximately 135,000 tonnes per day to 165,000 tonnes per day. Commissioning is scheduled for July 2030, with the expansion expected to increase copper production by approximately 30% from 2031.
The longer reserve life provides the ore inventory required to support the additional grinding capacity over an extended period. Sierra Gorda already has established mining and processing infrastructure, including power systems, water arrangements, a workforce and logistics facilities. The brownfield setting means the expansion is being developed at an existing operation rather than through construction of a new mine and processing complex.
Copper, Molybdenum and Gold Production
Sierra Gorda’s mineralisation contains copper alongside molybdenum and gold, giving the operation multiple payable metals and associated by-product credits.
At an average reserve grade of 0.39% copper, processing efficiency remains important because large quantities of ore must be mined and treated to produce contained copper. Grinding performance, recoveries, energy consumption and plant availability therefore remain important factors as throughput is increased. The fourth grinding line represents a capacity expansion as well as a productivity initiative, with the objective of processing more ore while maintaining recoveries and controlling operating costs.
The expansion will also have to be integrated into an operating mine. Its July 2030 commissioning target places construction and procurement ahead of the anticipated production increase beginning in 2031.
Sierra Gorda Extends KGHM’s Chilean Copper Base
The reserve increase gives KGHM a longer-term production platform in Chile, the world’s largest copper-producing jurisdiction. KGHM has major copper operations in Poland, while Sierra Gorda provides exposure to a large-scale open-pit operation outside Europe. The updated reserve base extends that exposure through 2045.
The operation’s existing infrastructure is also significant because new copper mines in Chile face permitting, water, infrastructure and capital requirements. Sierra Gorda can use its established facilities as the company expands processing capacity. The increase in Mineral Resources to 1.87 billion tonnes provides additional material beyond the current Ore Reserve. While not all Mineral Resources will necessarily become reserves, the larger inventory provides scope for future mine-plan optimisation, debottlenecking and processing improvements. The updated reserve and resource figures therefore provide KGHM and South32 with a substantially larger geological base for long-term planning as the partners proceed with the fourth grinding line.
