Gresik outage leaves PT Smelting with 100,000 mt of unprocessed copper concs

Indonesia's PT Smelting estimates that about 100,000 mt of copper concentrate has been left unprocessed due to repairs at its Gresik copper smelter, a spokesman for its main shareholder, PT Freeport Indonesia, said Aug. 22, providing some relief to a tight market.

PT Smelting operates the smelter, which was shut for a month to conduct maintenance, and was due to restart in August.

"Oxygen plant repairs at PT Smelting have delayed the smelter's startup after a one-month maintenance shutdown. Completion is expected in early September 2025," Katri Krinati, vice president of corporate communications at PTFI, said.

PT Smelting is a 65:35 joint venture between PTFI and Japan's Mitsubishi Materials Corp., with the former holding the bigger stake. Its Gresik smelter has a designed copper cathode production capacity of about 342,000 mt/year.

While the delay is expected to result in the unprocessed concentrate, "we are assessing its impact on PT Freeport Indonesia's upstream operations," Katri said. PTFI's upstream operations consist of the extraction of copper, gold and other minerals from the Grasberg mine in Papua province.

The Gresik plant maintenance has led to a copper cathode shortage in Southeast Asia, and the smelter was heard buying cathode from traders to deliver to end-users, market participants told Platts, part of S&P Global Energy.

Copper cathode spot premiums rose in the past week due to a shortage in Southeast Asia, while lower copper prices boosted demand.

Platts, part of S&P Global Energy, assessed Chinese copper import premiums at $55/mt plus London Metal Exchange cash on Aug. 21, CIF China, up by $5/mt from Aug. 8. The spot premium in Southeast Asia was heard at $90/mt for September delivery and pricing.

At the same time, more exports of Grasberg material provided relief to spot TC/RCs in Asian smelters.

Grasberg was heard to have transacted at a range of minus $10/mt to minus $35/mt from trader to smelter for the August-September loading laycan, which was higher than the Q4 loading clean copper concs TC/RCs level. A prompt loading laycan and high gold quality impacted the transaction level.

Platts assessed CIF China clean copper concentrate treatment and refining charges at minus $43.60/mt and minus 4.36 cents/lb, respectively, Aug. 21, down $1/mt and 0.1 cent/lb from Aug. 20.