China’s Zijin Mining Group Co. is considering an expansion of its jointly-owned copper mine in the Democratic Republic of Congo that would place it among the world’s biggest single sources of the metal.

Zijin would like to scale up the massive Kamoa-Kakula mine in the African copper belt to 1 million tons a year, Chairman Chen Jinghe said in an interview. That’s well beyond the existing target of about 600,000 tons, and would mean a challenge in scale to BHP Group Ltd.’s ageing Escondida mine in Chile.

“Research is being conducted and we are making plans” for 1 million tons, Chen said at Zijin’s headquarters in Xiamen on China’s southeast coast. The Congo project is a joint venture with mining billionaire Robert Friedland’s Ivanhoe Mines Ltd.

Kamoa-Kakula is among only a handful of large-scale, high-quality mines that have entered production in the past decade, just as demand for copper from green industries starts to accelerate. The facility is also a cornerstone of Zijin’s ambitions to be a top-three global copper producer.

Chen didn’t give further details of the expansion. He said the project still needed to “better control the investment and lower costs”, and he also pointed out issues with power supplies, logistics costs and transport bottlenecks.

Zijin and Ivanhoe both hold 39.6% of Kamoa-Kakula, while the DRC government has a 20% stake. Zijin also owns more than 10% of Ivanhoe.

“We are currently conducting an updated life-of-mine engineering study on the Kamoa-Kakula Copper Complex,” Ivanhoe Mines said by email. “Timing and investment decisions on any future expansions at the complex, including the proposed Phase 4 expansion, will be informed by the new mine study, which is expected in Q1 2025.”

The mine produced nearly 400,000 tons last year, Ivanhoe said last month, and it’s currently in the third phase of a ramp-up to more than 600,000 tons a year. Zijin has previously indicated plans for peak production at 800,000 tons.

Escondida, a decades-old mine run by BHP Group Ltd., produced about 1.07 million tons in 2023. Grasberg, a big copper mine in Indonesia run by Freeport McMoRan Inc., produced around 750,000 tons last year.