Thermal behavior of PrCl3 in an oxidizing condition

In this study, a thermal behavior of PrCl3 as one of the lanthanide chlorides in LiCl-KCl molten salts was investigated in an oxidizing condition. First, a thermo-gravimetric analysis (TGA) of PrCl3 was carried out by an injection of O2 gas. Based on the results, an oxidation of PrCl3 in the molten salts was performed by sparging O2 gas with changing temperatures. According to the TGA data of PrCl3 a dissociation of PrCl3 occurred rapidly by about 380 .deg. C and a conversion of PrCl3 to PrOCl was completed at about 600 .deg. C. The thermal behavior of PrCl3 in LiCl-KCl molten salts by sparging O2 gas was similar to that of PrCl3 in the TGA test, and PrOCl as a insoluble compound in the molten salts was precipitated into the bottom of the molten salts. A conversion of PrCl3 to PrOCl in the molten salts occurred actively at a higher temperature than 650 .deg. C. And it would be possible to estimate a conversion status of PrCl3 to PrOCl by measuring a Cl2 concentration in a flue gas generated from an oxidation test of PrCl3 in LiCl-KCl molten salts.