Capstone Copper has submitted the Mantos Blancos Phase II project to Chile’s Environmental Impact Assessment (EIA) process, beginning the permitting pathway for an expansion of the copper-silver operation in the Antofagasta Region. The proposed development would increase sulphide concentrator capacity to at least 27,000 tonnes per day, compared with the current design throughput of 20,000 tonnes per day. The project is focused on expanding an existing mining operation through additional processing capacity and infrastructure upgrades.
Concentrator Expansion Targets Higher Sulphide Throughput
Mantos Blancos Phase II includes an expansion of the sulphide concentrator along with upgrades to processing equipment. The project scope includes new equipment for concentrate filtration, thickening and tailings filtration, as well as modifications to existing process facilities. The planned development also includes a new in-pit tailings storage facility expected to operate beyond 2030, incorporating mine continuity requirements and tailings management infrastructure into the expansion plan.
Brownfield Development Supports Future Copper Supply
The expansion reflects continued investment in brownfield copper projects, where existing operations can provide a pathway for additional production capacity through infrastructure upgrades and processing improvements. The project requires assessment of several development areas, including permitting, tailings management, water requirements and maintaining operational continuity during construction and implementation.
Permitting and Studies Set 2030–2031 Expansion Timeline
Capstone expects the full Environmental Impact Assessment application to be followed by a pre-feasibility study in Q3 2026. Subject to approvals, sectoral permits and construction activities, expanded production is expected to begin between 2030 and 2031. The planned timeline includes regulatory review, additional technical studies and approximately one year of construction before the expanded facilities are brought into operation.
