Theoretical calculation and experimental study on the separation mechanism of PbS-Sb2S3

Abstract

Jamesonite (Pb4FeSb6S14) is a complex antimony sulfide mineral and an important raw material for the extraction of lead and antimony. Under vacuum conditions, the internal interaction mechanism of PbS and Sb2S3 during thermal decomposition is unclear and difficult to separate. In order to explore the interaction mechanism between PbS and Sb2S3, the thermodynamic data of Pb-S and Sb-S systems were firstly calculated by thermodynamic calculation method, PbS and Sb2S3 cluster substances that may exist in the gas phase were obtained under the given temperature conditions. On this basis, ab initio molecular dynamics was used to calculate the mean square displacement and diffusion coefficient of PbS and Sb2S3 gas phase clusters. The vacuum distillation experiments of lead sulfide and antimony trisulfide confirmed the volatilization and diffusion of PbS and Sb2S3, and verified the theoretical calculation results. According to the experiment, the volatilization temperature of Sb2S3 is much lower than that of PbS. The theoretical calculation results are consistent with the experimental results, which indicates that the calculation of the diffusion properties of PbS and Sb2S3 gas phase clusters by molecular dynamics simulation is reliable. This is also an effective and simple method to predict whether the mixed melt of PbS and Sb2S3 can be separated, which provides theoretical guidance for the vacuum separation of PbS and Sb2S3.