Studying Thermochemical Conversion of Sm2O3 to SmCl3 using AlCl3 in LiCl-KCl Eutectic Melt

Abstract

In this report the thermochemical conversion of Sm2O3 to SmCl3 using AlCl3 in LiCl-KCl melt at 773 K is discussed. The final product was a mixture of SmCl3, Al2O3, unreacted Sm2O3 and AlCl3 in the chloride melt. The electrochemical attributes of the mixture was analyzed with cyclic voltammetry (CV) and square wave voltammetry (SWV). The crystallographic phases of the mixture were studied with X-ray diffraction (XRD) technique. The major chemical conversion was optimized by varying the effective parameters, such as concentrations of AlCl3, duration of reaction and the amount of LiCl-KCl salt. The extent of conversion and qualitative assessment of efficiency of the present protocol were evaluated with fluorescence spectroscopy, UV-Vis spectrophotometry and inductively coupled plasma atomic emission spectroscopy (ICP-AES) studies of the mixture. Thus, a critical assessment of the thermochemical conversion efficiency was accomplished by analysing the amount of SmCl3 in LiCl-KCl melt. In the process, a conversion efficiency of 95% was achieved by doubling the stoichiometric requirement of AlCl3 in 50 g of LiCl-KCl salt. The conversion reaction was found to be very fast as the reaction reached equilibrium in 15 min.