Freeport-McMoRan declared force majeure at its Grasberg mine. Operations have been halted, and output in 2026 could fall by as much as 35%.

Freeport officially declared force majeure on supply contracts tied to its Grasberg Block Cave operations in Indonesia after a mud rush incident on 8 September. The accident blocked access routes, damaged infrastructure, and tragically killed two workers, with five still missing.

Grasberg, which accounts for ~3% of global mined copper and ranked as the world’s second-largest copper mine by production in 2024, will remain closed while investigations, damage assessments, and repairs are carried out. A restart is unlikely before early 2026, with full recovery expected only in 2027, underscoring the fragility of global copper supply.

The Big Gossan and Deep MLZ mines, which were unaffected by the incident, are expected to restart in Q4 2025. Grasberg Block Cave will undergo a phased ramp-up starting in H1 2026. However, extended disruptions cannot be ruled out. By comparison, the wall collapse at Rio Tinto’s Bingham Canyon mine in 2013 reduced its expected output by approximately 50% that year, with a full recovery taking even longer.

Freeport anticipates that its copper production in 2026 could fall by as much as 35% below the prior forecast of ~771kt Cu . The Grasberg Block Cave ore body alone contributes approximately 70% of PT Freeport Indonesia’s copper output through 2029, highlighting its central role in both Freeport’s operations and global copper supply.

Grasberg produced 816.4kt Cu in 2024. In H1 2025, production dropped to 297.1kt Cu, a 56% y-o-y decline. This reflected lower ore grades, reduced operating rates, and ongoing maintenance programmes. Copper concentrate from Grasberg is largely exported, with 864kt (gross) shipped so far in 2025, mainly to China (66%), Japan (14%), and South Korea (8%). Earlier this year, Freeport already warned of slower operations while awaiting repairs to its fire-damaged smelter.

The Grasberg incident compounds wider supply disruptions, including the seismic event that caused flooding in the DRC in May and a tunnel collapse at Chile’s El Teniente mine in July. Project Blue estimates losses of about 600kt Cu so far this year, approximately 3% of initial mine supply forecasts for 2025. We now expect a deficit of 923kt Cu in 2025, with 2026 also facing shortfalls. Our Q4 2025 price forecast remains unchanged between US$9,700–10,300/t.