Freeport-McMoRan (NYSE:FCX) says the phased ramp-up of its Grasberg Block Cave underground mine in Indonesia remains on track as it continues to recover from last year’s deadly mudslide.
Located in the remote highlands of the Sudirman Mountain Range in Central Papua, Grasberg is one of the world’s largest copper operations and comprises several underground mining zones.
Operations were disrupted in September 2025 when a massive mudflow struck the Block Cave mine, killing seven workers and forcing the suspension of mining activities.
Freeport has since restarted mining at several deposit areas, while operations at the Block Cave, where the incident occurred, are being gradually restored.
Grasberg ramp-up progresses
In an update on Friday, the US copper miner said Grasberg made “significant progress” with its phased ramp-up during the third quarter of 2026.
Mill throughput averaged approximately 140,000 tonnes per day during the quarter, representing around 67% of normalised rates before the September 2025 incident. This included approximately 70,000 tonnes of ore per day from the Block Cave mine.
Freeport continues to expect Grasberg to reach around 80% of capacity by mid-2027 before approaching full capacity by the end of next year.
The company previously estimated Grasberg’s copper production could reach around 800 million pounds in 2026 before increasing to 1.2 billion pounds in 2027 as the recovery progresses.
Freeport’s smelter in East Java, which was temporarily suspended following the Grasberg incident, also successfully restarted operations in late August.
Copper output meets expectations
Overall, Freeport estimates consolidated copper production of approximately 830 million pounds for the third quarter, in line with expectations.
The result reflects slightly stronger production from its international operations, offset by lower output in the US, where localised flooding, power outages, and strong winds affected operations, it says.
Freeport also expects quarterly copper sales of around 750 million pounds, with its average realised copper price forecast to exceed US$6.50 ($9.35) per pound.
The company says it is “strongly positioned for future growth opportunities” with ongoing progress on the Grasberg recovery, innovation-led growth, and potential organic brownfield development opportunities.
The Phoenix, Arizona-based miner is scheduled to release its third-quarter 2026 financial results before the market opens on 27 October.
Write to Jackson Chen at Mining.com.au
Main Image: Richarderari, Wikimedia Commons, under licence CC BY-SA 3.0
