Thermodynamic theory was employed in this study to investigate the feasibility of separating antimony (Sb) from crude arsenic (As) using vacuum sublimation. Ab initio molecular dynamics simulations are used to calculate the structure, stability, and diffusion properties of AsmSbn (m + n ≤ 6) clusters. As4, As3Sb, As2Sb2, and AsSb3 are the possible clusters in this thermodynamic calculation, and the molecular dynamics results confirmed their structural stability and stabilization in the gas phase. As4 had the largest diffusion coefficients, which is the reason it separates from the Sb-containing clusters (As3Sb, As2Sb2, and AsSb3) during gas-phase diffusion and condensation processes. The experimental results show that As vapor was transformed from crystalline to amorphous with increasing subcooling, and the Sb-containing clusters that enter the gas phase were mainly condensed and deposited at the proximal end of the heating zone. Not considering the volatilization rate, the removal rate of Sb in products can reach 99.35% by increasing the condensation disk and expanding the condensation zone; thus, experiments confirmed that industrial crude arsenic can realize deep Sb removal after vacuum sublimation.

中文翻译：

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真空升华去除工业粗砷中的锑：热力学与从头算分子动力学的结合

本研究采用热力学理论研究真空升华从粗砷（As）中分离锑（Sb）的可行性。从头算分子动力学模拟用于计算 AsmSbn (m + n ≤ 6) 团簇的结构、稳定性和扩散特性。 As4、As3Sb、As2Sb2 和 AsSb3 是该热力学计算中可能的团簇，分子动力学结果证实了它们的结构稳定性和气相稳定性。 As4 具有最大的扩散系数，这就是它在气相扩散和冷凝过程中与含 Sb 团簇（As3Sb、As2Sb2 和 AsSb3）分离的原因。实验结果表明，随着过冷度的增加，As蒸气从晶态转变为非晶态，进入气相的含Sb团簇主要在加热区近端凝结和沉积。不考虑挥发率，通过增加冷凝盘、扩大冷凝区，产品中Sb的去除率可达99.35%；由此，实验证实工业粗砷经真空升华后可以实现深度除锑。