Interaction of Rare-Earth Oxides with Binary Molten Mixtures of Zirconium and Alkali Metal Fluorides

摘要

Isothermal saturation,inductively coupled plasma mass spectrometry (ICP-MS),and X-ray pow-der diffraction were used to study solubilities of La_2O_3,Sm_2O_3,and Ho_2O_3 in the eutectic mixtures of LiF-ZrF_4,NaF-ZrF_4,and KF-ZrF_4 systems at temperatures from 873 to 1073 K.The solubilities of rare earth oxides in the molten fluorozirconate systems studied decrease in the increasing order of Ln~(3+) ion radii and in the increasing order of alkali metal cation radii in the binary mixture.The thermodynamic parameters of dis-solution calculated for the oxides imply the dominance of a chemical dissolution mechanism,and this impli-cation was supported by X-ray powder diffraction data.