Effect of ammonium, carbonate and fluoride concentration on the uranium recovery by resins

Abstract

Summary Uranium in solution can be precipitated over a wide pH range, from acidity and alkalinity, depending upon the solution and the precipitant used. The precipitate is generally filtered and the solution resultant contains uranium that should be recovered. This work is aimed at the selection of an appropriate resin for uranium recovery from alkaline solutions in the presence of ammonia, carbonate and fluoride. The ability of uranium extraction of 3 types of polymeric strong base resin was assessed. Laboratory solutions were prepared to determine the influence of the ions like ammonia, carbonate and fluoride on the uranium recovery by resins. The uranium concentration was 100 mg/L and the solution pH ranged from 9.2 to 10.4. The results, obtained by batch experiments, showed that excess of carbonate and fluoride completely inhibit uranium uptake in the pH range studied. Even low concentrations of fluoride and carbonate decrease uranium adsorption by resins. The optimum concentration was below 2.5 g/L (0.04 mol/L) and 5.0 g/L (0.26 mol/L) for carbonate and fluoride, respectively. The presence of high concentration of ammonia up to 20 g/L (1.20 mol/L) did not inhibit the uranium exchange process. Among the three types of resins studied IRA 910U was the most promising adsorbent for uranium at the conditions employed in this work.