Modeling the ultrapurification of substances by simple distillation

This paper presents a mathematical model for the ultrapurification of substances in a closed vaporization–condensation system, where the evaporation rate is determined by the combined effect of the mechanisms behind vaporization, condensation, and vapor transport from the vaporization surface to the condensation surface, and the impurity distribution in the liquid is determined by the diffusion mechanism. The degree of purification is evaluated as a function of the vaporization and condensation temperatures and the main simple distillation apparatus design parameters by numerical simulation for a particular example: removal of barium impurities from selenium.