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

Saeki, Morihisa; Esaka, Fumitaka  ; Taguchi, Tomitsugu; 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 palladium (Pd), rhodium (Rh), ruthenium (Ru) and neodymium (Nd) into distilled water. The Nd metal was added as representative of lanthanide and minor actinide. After 40-min irradiation of a mixture of the simulated solution of HLLW and ethanol (v/v = 1/1) with a UV laser (266 nm, 20 mJ), the Pd, Rh and Ru metals were separated from the Nd ion as particle with sub-micron size. The PGM particles were recovered by filtration and centrifugation. Analysis of ion concentration in the sample solution by ICP-AES suggested that 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.