Adsorption behavior of amidoxime resin for separating actinide elements from aqueous carbonate solutions

Abstract

Adsorption behaviors of actinide elements and major fission products (FP) in weakly-basic aqueous carbonate solutions to the amidoxime resin have been examined to separate U and Pu from FP under these solution conditions. Batch experiments have revealed that Pu(IV) and Pu(VI) have been adsorbed to the resin as well as U(VI) from 0.5 mol/dm 3 Na 2CO 3–NaHCO 3 solutions at pH 9 containing nitrate, and that the selectivity to the resin is Pu(IV)>Pu(VI) and U(VI)>Pu(VI), respectively. A column experiment using a similar carbonate solution containing U(VI), Ru(III), Pd(II), Zr(IV), Mo(VI), and Re(VII) has clarified that only U(VI) is adsorbed to the resin, that the other FP are passed through the column, and that the adsorbed U(VI) is eluted with 0.5 mol/dm 3 HNO 3. From these results, it is expected that the separation of U and Pu from FP can be carried out using weakly-basic aqueous carbonate solutions and amidoxime resin.