Chinese-owned mining companies operating in the Democratic Republic of the Congo have rejected allegations that cobalt exported from the country’s south-eastern mining belt contains uranium above legal or internationally accepted limits.
The Union of Chinese-Owned Mining Companies (USMCC) issued its denial on August 5, describing the allegations as “unfounded information” that could damage the reputation of the Congolese mining sector.
“After exhaustive verification, no cobalt product extracted, processed and exported by Chinese mining companies operating in the south-east of the DRC has excessive uranium content,” the association said in a statement shared by the Chinese Embassy in the DRC.
The USMCC said its members comply with Congolese mining regulations and analytical standards used in international trade. It also argued that cobalt hydroxide normally contains only “extremely weak natural traces” of uranium levels too low, in its view, to make commercial extraction technically or economically viable.
The collective denial follows an investigation published in late July by Lighthouse Reports. The investigation examined internal documents, mining data and scientific modelling related to cobalt production in the Katanga region, now largely within the provinces of Lualaba and Haut-Katanga.
Particular attention focused on the Tenke Fungurume Mining (TFM) operation in Lualaba Province. The mine was acquired in 2016 by China Molybdenum, commonly known as CMOC, from former owner Freeport-McMoRan.
According to the investigation, leaked TFM records showed uranium concentrations in cobalt material reaching as high as 1,100 parts per million in December 2016, approximately 15 times the Congolese export limit cited by the investigators. The records reportedly showed concentrations above the relevant threshold on more than 70% of recorded testing days between June 2016 and December 2020.
However, the published records do not establish that every tested batch was exported, nor that the uranium concentration remained unchanged after processing and before shipment. CMOC has repeatedly disputed the conclusions, saying that its cobalt hydroxide complied with applicable Congolese regulations and the procurement standards of international customers.
Between 2,000 and 5,000 tons of uranium may have been exported from the DRC to China from 2000 to 2024 within shipments of cobalt hydroxide, according to Nature Communications.
The estimate was developed through geochemical modelling of uranium concentrations in Katanga’s copper-cobalt deposits. Researchers also examined historical geological samples, mining production figures, chemical-supply data and information from leaked documents.
The investigation said the uranium was not necessarily shipped as an officially declared uranium product. Instead, it may have remained mixed with cobalt hydroxide as an incidental or undeclared by-product. The DRC officially prohibits uranium exports, making the issue relevant not only to mining regulation but also to nuclear-material safeguards and supply-chain oversight.
The researchers emphasized that their findings do not prove that the uranium was later separated, recovered or used in China. The estimate describes the quantity that may have been present in cobalt shipments, rather than confirming that an equivalent quantity became usable nuclear material.
China is the principal destination for Congolese cobalt, and approximately 95% of the DRC’s cobalt exports go to China, while China accounted for roughly 80% of global cobalt refining in 2023.
Cobalt hydroxide is an intermediate product used in the production of refined cobalt and battery materials. Cobalt remains an important input for many lithium-ion batteries, including those used in electric vehicles, as well as for aerospace alloys and other high-technology applications.
