China discovers new technology for extracting uranium from seawater
Scientists at Northeastern University in Changchun, China, recently developed a new technique for collecting uranium from ocean water.
The creation of a carbon fiber material that effectively extracts uranium from seawater offers a promising solution to access seawater’s vast uranium reserves. The invention heralds a breakthrough in uranium extraction technology and a new era in sustainable nuclear fuel.
Uranium is conventionally mined from rock sources, which are limited in supply. The Earth’s oceans and seas are estimated to hold approximately 4.5 billion tons of uranium. This is 1,000 times the quantity of uranium estimated to exist in land deposits.
The Chinese researchers successfully tapped seawater as a source of uranium. The approach could serve as an unconstrained source of carbon-free energy – if we could tap into this it would help fuel the transition to a carbon-free source of energy.
In seawater, dissolved uranium is found as tiny charged particles, or ions, which scientists call uranyl. Extracting uranyl from ocean water proves challenging because the materials used lack enough surface area, which hinders the effectiveness of trapping of uranium ions.
The researchers set about the difficult task of extracting them from seawater and developing a material to help them address the challenge. They used electrochemical extraction and a flexible cloth woven from carbon fibres to make the required electrodes. Using electrochemistry was three times as fast as natural accumulation, the researchers found.
The porousness of the carbon fibre cloth allows trapping of the uranyl ions. In the experiments, the researchers used the coated cloth as a cathode while using a graphite anode and running an electric current between them. When uranium ions precipitated at the cathode, the cloth turned a bright yellow.
The team also experimented with other materials to capture uranyl ions and found that the treated carbon fiber cloth performed the best. The researchers are working on scaling up this approach. The advance is significant as it presents a viable approach to tapping into the vast uranium reserves of the oceans for nuclear fuel.
The study was funded by the National Key R&D Programme of China and the National Natural Science Foundation of China. The research findings were published today in the journal ACS Central Science.
Sources:
Interesting Engineering, Dec 13, 2023. https://interestingengineering.com/science/seawater-source-of-nuclear-uranium
Sputnik International, Dec 14, 2023. https://sputnikglobe.com/20231214/chinese-scientists-invent-new-technology-for-extracting-uranium-from-seawater-1115569697.html