Exploring the vacuum distillation mechanism of PbS and Sb2S3 from ab initio and experiments perspective

Lead sulfide and antimony trisulfide are obtained through the vacuum thermal decomposition of Jamesonite. However, in this process, the microscopic mechanism and stability, which affects their deep separation, is unclear. This mechanism was explored under vacuum conditions using thermodynamics and molecular dynamics calculations along with experimental research. At 5 Pa, PbS decomposes and volatilizes at 1173 K and Sb 2 S 3 volatilizes at 923 K. The dynamic simulation results show that PbS are more likely to decompose and generate Pb and S 2 than Sb 2 S 3 . The fracture mode of the bond in the thermal decomposition process of PbS is layer-by-layer expansion between layers. The binding ability of Sb atoms and S atoms is also relatively strong, and the binding volatilizes outward in the form of Sb 2 S 3 . In addition, according to the vacuum distillation experiment, 5 Pa and 923-973 K are considered to be the best separation conditions for separating PbS and Sb 2 S 3 . Under this condition, Sb 2 S 3 is completely volatilized, while PbS is neither volatilized nor decomposed, and the separation rate reaches the maximum. Therefore, this study clarified the decomposition and volatilization mechanism of PbS and Sb 2 S 3 at the theoretical level, and provided guidance for sulfide separation experiments.