Major Chilean Copper Mine Slows Production Amid Strike

Written by Amir Richani for IIR News (Sugar Land, Texas)

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Summary

Mantoverde's Workers' Union #2 has been on strike since January 2, though a voluntary mediation on Monday 5 could resolve the situation. The mine is operating at up to 30% capacity.

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Production Drops After Talks Fail

Union #2, the labor union at Capstone Copper Corporation's (Vancouver, British Columbia) Mantoverde Copper Mine in Chanaral, Chile, began a strike January 2, following failed negotiations between the company and the union. According to local newspaper El Zorro Nortino, a voluntary mediation by Chile's Labor Inspectorate is expected Monday, January 5, at 19:00 Chile time to try to resolve the issue.

In a statement, Capstone, the owner of the asset, said that the mine will operate at up to 30% of its normal production during the strike. Subscribers to Industrial Info's Global Market Intelligence (GMI) Metals & Minerals Plant Database can learn more about the Mantoverde Copper Mine in a detailed plant profile.

Union #2 represents 50% of Mantoverde's employees, equivalent to 22% of the total workforce. More than 600 employees have joined the strike. In 2025, Mantoverde negotiated a new three-year collective bargaining agreement with the other three unions at the mine.

In addition to disagreements within the contract negotiations, the union opposes the deployment of private security to the asset, which is says is used to "intimidate" workers.

The Mantoverde mine produced 23,300 tons of copper cathodes and 48,000 tons of copper concentrate during the first three quarters of 2025. The third quarter of 2025 closed with 8,550 tons of copper cathodes and 15,200 tons of copper concentrate.

Mantoverde's Development

During the third quarter, Capstone continued its drilling program as part of the Mantoverde Optimized Pit Reserves, which yielded higher-than-expected grades in the Brecha Flores sector. The optimization program, which includes a proposed sulphide concentrator, aims to expand production from 32,000 to 45,000 tons per day of ore, allowing the company to increase copper output by 20,000 tons per annum and gold output by 6,000 ounces per year.

Subscribers can learn more about Capstone's sulphide concentrator from a detailed project report.

Industrial Info is tracking 11 projects related to the Mantoverde mine, totalling investments of US$951 million, including the Mantoverde-Santo Domingo integration plan. Subscribers can learn more from a detailed list of project reports.

Capstone owns 70% of Mantoverde, with Mitsubishi Materials owning the other 30%.

Key Takeaways

• Workers at Capstone's Chile Mantoverde mine are on strike.
• A meeting on Monday 5 could help resolve things.
• IIR is tracking 11 projects related to Mantoverde.

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Industrial Info Resources (IIR) is the leading provider of industrial market intelligence. Since 1983, IIR has provided comprehensive research, news and analysis on the industrial process, manufacturing and energy related industries. IIR's Global Market Intelligence (GMI) helps companies identify and pursue trends across multiple markets with access to real, qualified and validated plant and project opportunities. Across the world, IIR is tracking more than 200,000 current and future projects worth $17.8 trillion (USD).