Separation of arsenic and antimony: A comprehensive theoretical and experimental study

Arsenic is commonly used in alloy materials and the semiconductor industry, and has promising applications. Arsenic and antimony have similar physicochemical properties, and their binding and separation mechanisms are unknown, thereby limiting the purification and preparation of arsenic. This study, from a microscopic perspective, reveals that arsenic and antimony covalently interact in alloys through a combination of thermodynamic analysis and molecular dynamics simulations. In addition, antimony as arsenic-antimony clusters enters the gas phase, and the diffusion coefficients of the clusters are in the order of As4>As3Sb > As2Sb2>AsSb3. A green and efficient vacuum sublimation-graded condensation process for arsenic purification is proposed based on the different diffusion coefficients to obtain the optimal process parameters. The coalescence of arsenic on a condenser was normally distributed. The removal rate of antimony in the most concentrated area of the condensate was 91.37% under the optimal conditions of 748 K, 60 min, and 10 Pa. Thus, the proposed method effectively solves the challenging problem of separating arsenic and antimony, and the study results provide theoretical support for purifying arsenic via vacuum sublimation.