Freeport McMoRan has suspended operations at its Grasberg Block Cave mine in Central Papua, Indonesia, after a substantial flow of wet material obstructed access underground, limiting evacuation pathways for seven contractor workers.
The company confirmed that the location of the trapped workers is known and that they are believed to be safe.
Rescue and support efforts are ongoing as teams work to clear the blockage and create secure evacuation routes.
The Grasberg Block Cave mine, managed by PT Freeport Indonesia (PTFI), is one of the most significant sources of copper and gold globally.
Freeport McMoRan, through its 48.76 per cent ownership interest in PTFI, oversees the underground operations, one of the largest of its kind.
The mine produces not only copper and gold but also silver, with ore extracted using remotely operated equipment from deep underground panels.
The incident underscores the operational challenges faced at large-scale block cave mines where geological conditions and material flows can impact access and safety.
The priority, Freeport McMoRan emphasised, remains on ensuring the security of personnel, with technical teams mobilised to stabilise the flow areas and determine a safe evacuation plan.
Local authorities are also being kept informed of ongoing developments.
The Grasberg complex, situated in the Grasberg minerals district, has long been a cornerstone of Indonesia’s mining sector.
It remains one of the largest reserves of copper and gold in the world and plays a central role in regional economic activity.
Operations have in recent years shifted more heavily towards underground block cave mining after the closure of Grasberg’s open pit in 2019.
While the immediate focus is on worker safety, the suspension comes during a period of mixed financial results for the company.
In the first quarter of this year, Freeport McMoRan reported profits slightly above expectations but posted a decline in net income attributable to common shareholders.
Net income fell to US$352 million, or US$0.24 per share, in the quarter ending March 31, compared with US$473 million, or US$0.32 per share, a year earlier.
Copper production also tracked lower in the period. Consolidated copper output totalled 868 million pounds in the first quarter, down from 1.09 billion pounds in the same quarter of the previous year.
The decline reflected a transition in production phases at Grasberg as well as variable mining conditions, factors that remain influential on the company’s revenue streams.
The mine’s contribution to Freeport McMoRan’s global portfolio of assets remains substantial, given the scale and quality of its ore body.
Disruptions of this kind not only impact short-term operations but also draw attention to the complexities of cave mining at depth, where water, rock mass behaviour and ore flow present unique risks.
Freeport McMoRan reiterated that its teams are in regular communication with the trapped workers and that all available resources are being dedicated to securing their safe evacuation.
Industry observers noted that while production impacts are inevitable in the near term, stakeholder focus will remain on the outcome of the evacuation effort and the safety of personnel in Central Papua.
