China Develops Uranium Extraction Method From Seawater That Outperforms U.S. Benchmark

Chinese scientists have developed a new material that captures uranium from seawater far more efficiently than existing technologies, according to research reported by the South China Morning Post. The material, called PhosCage, exceeded a benchmark established by U.S. specialists by more than eight times.

A team from the Chinese Academy of Sciences in Qingdao created a spongy molecular structure whose phosphate groups act as chemical traps for uranium. In tests using natural seawater, the material extracted up to 50.4 milligrams of uranium per gram of adsorbent. The benchmark set by the U.S. Department of Energy was 6 milligrams per gram.

The researchers later converted PhosCage into millimeter-sized spheres for possible use in the ocean. Those spheres captured 22.55 milligrams of uranium per gram and survived seven reuse cycles. The team said the work “opens a new approach to uranium extraction from seawater and lays the foundation for creating adsorbents capable of capturing more uranium and ultimately being used on a large scale.”

The development has particular importance for China, which is expanding nuclear energy while relying on uranium imports. Chinese deposits produced about 1,600 tons of uranium in 2024, compared with estimated reactor needs of about 13,000 tons. Seawater contains an estimated 4.5 billion tons of uranium, far more than the roughly 7.9 million tons in proven land reserves.

Commercial use remains far away. A ton of seawater contains only about 3.3 milligrams of uranium, while elements such as vanadium complicate separation. U.S. researchers at Oak Ridge and Pacific Northwest national laboratories developed similar materials, but the approach proved too expensive compared with conventional mining, and the program was largely discontinued after 2018. The Chinese research appeared in the Journal of Hazardous Materials and Separation and Purification Technology, and researchers said PhosCage can selectively capture uranium even when other metals are present.

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This work opens a new approach to uranium extraction from seawater and lays the foundation for creating adsorbents capable of capturing more uranium and ultimately being used on a large scale.