Liquid-vapour Phase Equilibrium in Metal Systems and Parameters of Vacuum Distillation Processes Forecasting

摘要

Calculation methods of liquid-vapour phase transition boundaries in metal systems at atmospheric and low pressure are indicated. Examples of thallium-lead, copper-cadmium, cadmium-zink, lead-antimony phase diagrams are given to illustrate possibility of the system's components separation processes forecasting predicting by their evaporation. Influence of the pressure decrease on the phase transition boundaries position is studied. It is shown that the liquid-vapour phase transitions in vacuum allowed to estimate value of energy consumption decrease due to lowering the solutions' boiling point and possibility of one of the metals preferential evaporation. Based on the form of the solutions and vapour coexistence area it is possible to determine vapour phase equilibrium composition and, hence, condensate in the distillation process as well as minimal allowable rarefaction, below which a solid phase precipitation from the distillate takes place.