Uranium from the sea

Estimates of uranium sources on land are a little over two and a half million tonnes. In contrast, the amount in the sea runs to over one and a half thousand times as much. But its concentration is only about three parts per thousand million, so exploiting it poses enormous problems. Nevertheless, a promising technique for doing so is now emerging, based on a continuous process, harnessing the flows of ocean currents. It is described under the headings: sea trials; extraction; chelating groups. Fine polymer ion-exchange fibres are used to take up the uranium. (author)