Study on separation of platinum-group metals by using laser-induced particle formation

Saeki, Morihisa; Toshimitsu, Masaaki; Oba, Hironori  

We proposed separation technique of platinum-group metals (PGMs) from a solution of high-level radioactive waste by using laser-induced particle formation, and performed its proof-of-principle experiment. The simulated solution of high-level radioactive liquid wastes (HLLW) was prepared by dissolving Pd, Rh, Ru and neodymium (Nd) into distilled water. The Nd metal was added as representative of lanthanide and minor actinide. After 40-min irradiation of an UV laser to mixture of the simulated solution of HLLW and ethanol, the Pd, Rh and Ru metals were separated from the Nd ion as particle with sub-micron size. The Pd, Rh and Ru metals were recovered with efficiency of 100%, 94-99%, 65-69%, while the Nd ion was completely kept in the sample solution. Moreover, we investigated dependence of recovery efficiency on various experimental parameters. The results suggest mutual separation of Pd and Rh by arrangement of the intensity of the irradiation laser.