Copper shipments from Indonesia face delays as Gresik smelter shut by boiler leak

Copper exports from Indonesia are encountering disruptions following the weekend shutdown of the smelter that processes ore from the massive Grasberg mine, after a boiler leak forced an immediate halt to operations. Buyers supplied by the Gresik facility-which handles material from the mine jointly owned by the Indonesian government and Freeport-McMoRan Inc.-have been notified that the plant will remain closed for assessment and repair work over the coming weeks, according to sources familiar with the matter.

The Gresik smelter is operated by PT Smelting, a joint venture between Mitsubishi Materials Corp. and PT Freeport Indonesia---the latter being an entity controlled by Freeport and the Indonesian state. A Freeport spokesperson indicated that preliminary assessments suggest repairs could be completed by the end of September, while the company is also working to bring its own Manyar smelter online earlier than previously scheduled. Freeport is adjusting its shipping timetable with the aim of restarting Manyar in late August, they added.

Mitsubishi Materials earlier confirmed to Bloomberg that operations at the Gresik facility had been suspended following the August 8 breakdown. Meanwhile, the giant Grasberg mine in Indonesian Papua has resumed partial operations after mudflow issues hampered production last year, though a full recovery is expected to be protracted and may extend into 2028. Freeport's Manyar smelter is also slated for a September restart to process additional ore from the mine.