Gecamines, which ranked among the world's top copper and cobalt producers in the 1980s, also aims to boost production and "play in the big leagues" again, Kaputo said in a speech at the Investing in African Mining Indaba in Cape Town.

Gecamines, whose production peaked in 1986 at 486,000 tonnes of copper, wants to raise output to 100,000 tonnes of copper a year, Kaputo said. Gecamines produced 4,562 tonnes of copper and 19,907 tonnes of cobalt in 2022, provisional statistics from Congo's central bank showed.

"Our geologists will aim to organise prospection campaigns on all our sites to look for lithium, tin, cobalt, coltan, titanium, wolframite, gold, rare earths, etcetera," Kaputo said, as part of efforts to diversify Gecamines' activities.

He invited investors to speak to Gecamines about "win-win partnerships" to exploit those metals.

Among the obstacles Gecamines faces are artisanal miners working illegally on the sites it owns, Kaputo said, adding that these wildcat miners "sell all their minerals to foreign buyers".

Congo loses untold fortunes through the smuggling of resources including gold and tin, tantalum, and tungsten ores.

Industrial mines must systematically plan to work alongside artisanal miners, where possible, Kaputo said.

"That is crucial, as we can no longer tolerate the disgraceful conditions in which artisanal diggers work, and we can no longer tolerate that our state and Gecamines, whose concessions are illegally exploited, be robbed of their riches," Kaputo said.

(Reporting by Helen Reid; editing by Barbara Lewis)