Scientists find new way to extract uranium from seawater

A group of scientists form Stanford University is working on a new method to extract uranium from the ocean, which could be particularly useful in areas with no uranium mines but that need the material to power nuclear plants.

The team’s main goal is to come up with a much more environmentally friendly alternative to extracting the radioactive material than the current mining techniques, according to a statement.

A method for extracting high quantities of uranium in a short time could help make nuclear power a viable part of the quest for a carbon-free energy future, the team says.

While the presence of traces of uranium in seawater has been a known fact for years, the amounts present are very low and difficult to extract. But if the researchers at Stanford University can prove their method is cost effective, the situation could quickly change.

“Concentrations are tiny, on the order of a single grain of salt dissolved in a liter of water,” Yi Cui, one of the researchers, said in the statement. “But the oceans are so vast that if we can extract these trace amounts cost effectively, the supply would be endless.”

When uranium comes in contact with the oxygen from the ocean, it forms the compound uranyl. The team plans to collect the vast supplies by using amidoxime, a compound that would pull only uranyl from the water. The amidoxine coats a pair of carbon electrodes, which are able to accumulate large amounts of the uranyl that could then be sent off for processing.

The scientists put their method to the test and found they were able to extract three times as much uranyl in an 11-hour period compared to their previous method of using only an amidoxine-coated brush. The new method also sustained the electrodes for future uses.

Despite the team’s success, there is a long way to go before large-scale application. To be commercially viable, the benefits of the extraction method must outweigh its costs. The process also needs to be streamlined to treat large quantities of water. "We have a lot of work to do still but these are big steps toward practicality," Cui concludes.

If successful, the method could make of nuclear power generated with uranium extracted from seawater a renewable energy, as it's continuously replenished, just as solar, hydro and wind.

The researchers’ findings have been published in the journal Nature.