In July 2026, an article published in Nature Communications claimed that between 2 and 5 thousand tons of natural uranium could have been exported from the Democratic Republic of Congo (DRC) over the past 20 years. According to the study's authors, the radioactive metal was not exported as a separate raw material, but as an impurity within cobalt hydroxide – an intermediate product used in the production of materials for lithium-ion batteries.

The Need for Cobalt

Cobalt is a key component of cathode materials, such as lithium cobalt oxide (LiCoO₂), which became the foundation for lithium-ion batteries developed by John Goodenough and his colleagues in 1980. This discovery enabled the creation of high-capacity, compact batteries for portable electronics.

Although cobalt ores are found in various countries, the majority of global cobalt production comes from the DRC. This is due to the presence of the copper-cobalt belt that runs through the southern part of the country. Copper ores in this region are characterized by high cobalt content, making its extraction a byproduct of copper mining. In 2024, the DRC accounted for approximately 76% of the world's cobalt production.

However, cobalt mining in the DRC is associated with serious challenges, including the use of child labor in artisanal mines and poor working conditions in official enterprises. International human rights organizations estimate the proportion of artisanal miners to be between 10% and 30%. Working in such conditions carries risks of mine collapses, inhalation of toxic dust that causes lung fibrosis and asthma, as well as an abnormally high rate of congenital central nervous system defects in children born to women living near the mines.

Despite these challenges, the demand for cobalt continues to grow with the development of alternative energy, which requires energy storage for solar and wind power plants.

Uranium in Congolese Deposits

The presence of uranium in DRC deposits is not new information. The Shinkolobwe mine in Upper Katanga province was a source of uranium for the Manhattan Project in 1945. This mine has been officially closed since 2004, and the Republic of Congo has not reported any uranium exports to the International Atomic Energy Agency (IAEA).

Typical ore from the copper-cobalt belt contains about 10% iron, 2-5% copper, a few tenths of a percent cobalt, and tens to hundreds of parts per million uranium. When processing large volumes of ore, even such low concentrations of uranium can represent significant quantities.

Researchers Ryan Manzuck and Sebastian Philipp from the University of Wisconsin-Madison studied the ore processing. After crushing and treatment with sulfuric acid, the metals are dissolved. Copper is extracted in the first stage. The solution is then neutralized with lime or alkalis to precipitate cobalt hydroxide. During neutralization, uranium, which forms sparingly soluble compounds at a pH of around 6.1, precipitates along with the cobalt hydroxide (which precipitates at a pH of around 6.8). The pH difference is too small for complete separation.

At DRC mines, final purification is often carried out at a pH of 5.5 or lower to avoid cobalt loss. This allows for the removal of no more than 50% of the uranium from the solution. The remaining uranium ends up in "tailings" – waste products that are often not designed to handle uranium-containing materials and can pose a risk of uranium migration into the environment.

Solutions and Scale of the Problem

There are two main approaches to removing uranium from solution: using ion-exchange resins or adding phosphoric acid, which converts uranium into the poorly soluble mineral autunite. However, in the DRC, these reagents are not produced, and companies must purchase them from abroad. Analysis of customs records showed that only three companies purchased enough phosphoric acid to process their entire volume of cobalt hydroxide, and no signs of ion-exchange resin use were found. By 2024, only about 20% of cobalt exports were processed through a uranium removal scheme.

Based on the uranium content in ores, cobalt production volumes, and various company operating scenarios, researchers estimate that between 1.5 and 2.5 thousand tons of uranium could have been exported from the DRC over 20 years. In some cases, with elevated uranium content in the ores, this volume could exceed 5 thousand tons. An additional 3 to 4 thousand tons of uranium could have accumulated in unstable waste within the DRC. The authors emphasize that this refers to by-product generation, not targeted uranium mining.

Uranium in Final Products

The probability of uranium ending up in a final battery is extremely low. The process of purifying cobalt hydroxide and the subsequent production of cathode materials, such as lithium cobalt oxide, involve steps that eliminate the presence of uranium. Furthermore, if uranium were to be present in the battery, it would lead to its rejection due to degraded performance.

A known case involved the Finnish company Kokkola, which processed cobalt raw materials from the DRC in the 2010s, extracted, purified, and declared the resulting uranium. However, most of the unaccounted-for uranium likely ended up in processing waste and is located in tailings ponds and landfills.

The main problem is that the movement of such uranium is not tracked as the movement of nuclear material. The current control system, designed for the uranium industry, has proven unsuitable for situations where uranium is incorporated into other supply chains.

Solving this problem requires a comprehensive approach within the DRC: implementing uranium purification at processing plants, inspecting batches of cobalt hydroxide, and strengthening control over tailings ponds.

Alternatives to Cobalt

The need for cobalt can be reduced by using alternative materials for the cathodes of lithium-ion batteries. Some modern laptops already use cathodes based on mixed nickel-manganese-cobalt oxides (NMC), where part of the cobalt is replaced by other metals. Base versions of the Tesla Model 3 have switched to lithium iron phosphate (LFP) batteries, which do not contain cobalt, although they have a slightly lower energy density. LFP batteries are also used in storage for solar power plants.

Effective methods for extracting cobalt from old batteries are also being developed. Accelerating the transition away from cobalt dependence can be stimulated by the scandal involving unaccounted-for uranium.