Reaction of Oxygen with Solutions of Neodymium Chloride in Alkali Chloride Melts: A Spectroscopy and Kinetics Study

Abstract

Reaction of oxygen with solutions of neodymium chloride in LiCl and 3LiCl–2KCl melts was studied at 450 °C–750 °C. The reaction resulted in the formation of neodymium oxychloride and the effect of temperature, amount of oxygen passed through the melt (oxygen-to-neodymium molar ratio), gas phase composition (O2, O2–H2O, Ar–O2, Ar–O2–H2O) on the course of the reaction were considered. Size of particles comprising solid precipitates formed in the melt was determined. High temperature electronic absorption spectroscopy was used to determine kinetic parameters of the reaction (reaction rates, rate constants, temperature coefficients). The activation energy of the reaction was evaluated.