Title: Development of monoamide resins for selective recovery of uranium(VI) from nitric acid media

Biography:

Abstract

Uranium(VI) (UO22+, uranyl ion) is the most stable U species in aqueous nitric acid solutions. Separation of U(VI) from HNO3 containing U(VI) and other metal ions is very important to treat radioactive wastes. Chromatographic separations have an advantage compared with solvent extraction techniques for separation in small and medium scales, because of better separation properties by a multistage processing with compact equipment and easier handling. We have developed novel resins with selectivity to U(VI) in HNO3 media. The functional groups have the structure of monoamides (RR’NCOR”: R, R’, R”; hydrocarbon groups) which have been studied as extractants for actinide (An(IV) and An(VI)) species in HNO3 media. In the present study, resins of synthetic monoamide polymers supported on the surface of porous silica and their adsorptivities to U(VI) to major fission product ions (FPs) will be introduced together with a commercial monoamide resin. We will show that the adsorptivities of the resins to U(VI) and FP ions are dramatically affected by the changes in the chemical structures of the monoamide groups. Mutual separation of An(IV) and An(VI) by the resins and stability against gamma-ray irradiation of the resins will also be presented.