Volatilization kinetics and thermodynamic stability of antimony sulfide under vacuum conditions

Antimony sulfide can be produced by vacuum distillation of lead antimony sulfide ore. In this paper, the volatilization kinetics of antimony sulfide under vacuum conditions was studied for the first time using a self-made vacuum furnace, and the stability of antimony sulfide was explained through thermodynamic calculations. The results show that under a system pressure of 20 Pa and a temperature range of 873 K–1073 K, the apparent volatilization activation energy of antimony sulfide is 57.6 kJ/mol, and the volatilization control step of antimony sulfide is a gas phase diffusion process. As the temperature increases from 873 K to 1073 K, the volatilization rate of antimony sulfide increases from 0.20 g cm −2  min −1 to 0.88 g cm −2  min −1 by 4.4 times. As the system pressure increases from 20 Pa to 100 Pa, the volatilization rate of antimony sulfide decreases rapidly, decreasing by nearly 11.4 times. Antimony sulfide will not decompose within the range of system pressure above 20 Pa and temperature below 1073 K.