Partitioning of rhodium and ruthenium between Pd–Rh–Ru and (Ru,Rh)O2 solid solutions in high-level radioactive waste glass

Abstract The partitioning of rhodium and ruthenium between Pd–Rh–Ru alloy with a face-centered cubic (FCC) structure and (Ru,Rh)O 2 solid solution has been investigated between 1273 and 1573 K at atmospheric oxygen fugacity. The rhodium and ruthenium contents in FCC increase, while the RhO 2 content in (Ru,Rh)O 2 decreases with increasing temperature due to progressive reduction of the system. Based on the experimental results and previously reported thermodynamic data, the thermodynamic mixing properties of FCC phase and (Ru,Rh)O 2 have been calibrated in an internally consistent manner. Phase equilibrium of platinum grope metals in an HLW glass was calculated by using the obtained thermodynamic parameters.