Extracting uranium from ocean water? Done
When we think of the oceans, we tend not to think of them as large depositories of uranium, the key ingredient in nuclear power production. We might as well start doing so, though.
Researchers at Pacific Northwest National Laboratory (PNNL) and LCW Supercritical Technologies in the United States have managed to produce five grams of yellowcake (a powdered uranium concentrate used to produce fuel for the generation of nuclear power) by extracting uranium from seawater. They did so by using simple acrylic fibers. “This is a significant milestone,” Gary Gill, a researcher at PNNL, said. “It indicates that this approach can eventually provide commercially attractive nuclear fuel derived from the oceans — the largest source of uranium on earth.”
To obtain uranium from the oceans, the scientists developed a specially designed acrylic fiber that attracts and then retains dissolved uranium from seawater. During the extraction process uranium is absorbed onto a molecule or ligand that is chemically bound to the acrylic fiber, which is durable and reusable. When submersed in seawater, the yarn automatically extracts uranium sloshing about.
“We have chemically modified regular, inexpensive yarn to convert it into an adsorbent which is selective for uranium, efficient and reusable,” Chien Wai, president of LCW Supercritical Technologies, explained. “PNNL’s capabilities in evaluating and testing the material have been invaluable in moving this technology forward.”
The world’s oceans contain an inexhaustible supply of uranium. The problem so far has been that extracting it in cost-effective ways has not been possible because uranium is contained in much diluted form in the sea. Wai’s team has now made important inroads into mining the world’s oceans for uranium in a cheap and simple manner. The adsorbent polymer material they have designed can be produced even from waste yarn. For the first time, the process of obtaining uranium from ocean water is now economically feasible as a viable alternative to land-based mining.
