Volatilisation kinetics of Sb₂S₃from PbS–Sb₂S₃melt

Abstract

The kinetics of volatilisation of Sb2S3 from PbS–Sb2S3 melt was investigated by measuring volatilisation ratio of antimony. A theoretical model was set up to calculate the overall rate constant and the mass transport coefficient in gas phase. It has been demonstrated that the volatilisation process displays first order kinetics with respect to the concentration of Sb2S3 in the melt. The apparent activation energy for the process is found to be 81·18 kJ mol−1. The effect of concentration of Sb2S3, temperature and carrier gas flow rate on the volatilisation rate was discussed. The activity of Sb2S3 shows positive deviation from Raoult's law because the complex sulphides may be formed between Sb2S3 and PbS.