Theoretical Study on the Separation of Impurity Tellurium from Crude Selenium by Vacuum Distillation

Theoretical research on the separation of tellurium by vacuum distillation from crude selenium could provide further key data support for industrial production. In this work, theoretical and experimental studies on the separation of tellurium impurities from crude selenium by vacuum distillation were systematically carried out. The saturated vapor pressure, separation coefficient, vapor–liquid equilibrium composition, average molecular free path, and evaporation rate characteristics of selenium and tellurium under different distillation conditions were calculated theoretically. We conducted research on the volatilization characteristics of crude selenium and measured the volatilization rate of crude selenium under pressures of 498–573 K and 10–500 Pa using the vacuum differential method. The volatilization rate values of crude selenium under different conditions were obtained, and the influences of distillation temperature and system pressure on the volatilization rate of crude selenium were uncovered.