Metal vapour condensation at reduced pressures

In the process of extracting silver from lead bullion, zinc is added to the lead bullion to form a zinc crust. The crust is subsequently distilled and metallic zinc is condensed for reuse. In the present work, four aspects of the process were studied: the thermodynamic properties of zinc in zinc crust (the Pb-Ag-Zn ternary system); the heat and mass transfer of zinc vapour in a vertical tube condenser in the presence of a non-condensable gas; the cooler-condenser design for the vapour and gas mixture; and the zinc vapour condensation behaviour