The thermodynamic properties of liquid and vapor in the cadmium-thallium-lead system

The liquid-vapor phase transitions boundaries were calculated on the basis of the values of vapor pressure of the components in the lead-bismuth system during the stepwise pressure decrease by one order of magnitude from 10⁵ down to 1 Pa. The emergence of azeotropic liquid under pressure lower than 19.3 kPa was ascertained. The emergence of azeotropic mixture near the lead edge of the phase diagram was concluded to be the reason for technological difficulties in the distillation separation of the system into the components in a vacuum.