Chinese Scientists Pull Uranium From Seawater 8 Times Faster Than the US Target

Researchers at the Chinese Academy of Sciences (CAS) in Qingdao say they have extracted uranium from seawater at several times the rate targeted by the US Department of Energy, using a material they call PhosCage, a sponge-like molecular structure filled with phosphate groups that trap uranium chemically.

The team, from the CAS Qingdao Institute of Bioenergy and Bioprocess Technology, said it recovered up to 50.4 milligrams of uranium for every gram of the adsorbent from natural seawater samples, more than eight times the department's target of 6 milligrams per gram. Shaped into millimetre-sized beads for easier deployment and retrieval at sea, the material captured 22.55 milligrams per gram and kept working through seven cycles of reuse.

A tonne of seawater holds only about 3.3 milligrams of uranium, so large volumes of water must be filtered to collect it, and other dissolved elements such as vanadium tend to stick to the same chemical traps, making separation difficult. In tests with several metals present, the CAS team's bead-like material showed a clear preference for uranium over vanadium, according to two papers published in the Journal of Hazardous Materials and Separation and Purification Technology.

The world holds about 7.9 million tonnes of known uranium resources on land, compared with an estimated 4.5 billion tonnes dissolved in the oceans. China produced just 1,600 tonnes of uranium domestically in 2024, a fraction of the roughly 13,000 tonnes its nuclear reactors require, according to the World Nuclear Association, leaving the country reliant on imports.

The experiments were run in a laboratory flow system using 25 litres of seawater collected off the coast of Qingdao, rather than adsorbents left in the open ocean, where waves, currents and marine life would make the task harder. Neither study put a price on the recovered uranium; the researchers said further work would focus on scaling up the material and lowering the overall cost of extraction.