Capstone Copper restarts Chile's Mantoverde mine while strike continues
Capstone Copper resumed operations at its Mantoverde copper and gold mine in northern Chile, even as a strike by a labor union representing nearly 22% of its workforce continued, the Canadian miner said on Monday.
The company, in an Australian exchange filing dated February 1, reiterated it expects to continue operations at a level between 50% to 75% of normal production during the strike.
Shares of Capstone's Australia-listed depositary receipts CSC.AX fell as much as 4.5% to A$15.810 on the day, their lowest level since January 23.
The decision to resume operations follows a Chilean court ruling last week authorizing the forced removal of striking workers from a desalination plant supplying water to the mine, a key resource for day-to-day operations.
The strike began in January after negotiations over new labor contracts with Union No. 2 of Mantoverde broke down. Unionized workers rejected the company's latest payment offer, leading to the ongoing impasse.
Capstone said it remains open to further dialogue with the union as it seeks to resolve the dispute.
Union No. 2 at Capstone Copper’s Mantoverde mine is the largest labor union on site, representing around 645 workers, which corresponds to roughly 50% of the mine’s direct workforce. It is the union leading the strike.
The conflict centers on Mantoverde's desalination plant on the coast, located about 40 km from the mine.
The company reported that on the evening of January 18, individuals entered the desalination facility, interfering with the plant's electrical system and causing an interruption in water supply.
The water shortage forced the mine to rely on on-site reserves, halt parts of its operations including sulphide processing, and warn further shutdowns could occur if the situation persisted.
Chile, the world’s top copper producer, has grappled with deepening droughts that have forced Santiago to consider unprecedented water rationing.
The shortages have intensified long‑standing tensions over water use as miners - traditionally dependent on continental sources like lakes, rivers and reservoirs - compete for supplies needed to power copper smelting.
In 2025, Mantoverde produced 62,308 tons of copper concentrate and 32 807 tons of copper cathodes, about 0.4% of global production.
Capstone owns a 70% stake in Mantoverde, with Japan's Mitsubishi Materials holding the remaining 30%.
