The Removal of Uranium from Acidic Media Using Ion-Exchange and Extraction Chromatography

The separation and purification of uranium from either nitric acid or hydrochloric acid media can be accomplished by using either solvent extraction or ion-exchange. Over the past two years at Los Alamos, emerging programs are focused on recapturing the expertise required to do limited, small quantity processing of enriched uranium. During this period, we have been investigating ion-exchange as a method for extraction/purification of uranium from acidic media. In addition, waste stream polishing is associated with this effort in order to achieve more complete removal of uranium prior to recycle the acid. Extraction chromatography has been demonstrated to further polish uranium from both nitric and hydrochloric acid media, thus allowing for a more complete recovery of the actinide material and creation of less waste during the processing steps. We discuss contact experiments for evaluating eleven different resins for uranium removal from nitric acid, the elution of uranium from ion-exchange media, and small-scale removal of 235U from nitric acid. Larger-scale flow experiments, using depleted uranium, were completed subsequent to small-scale evaluations. This includes a discussion of the shortcomings of contact experiments and how flow experiments were modified to overcome these problems.