KINETICS OF ZN AND PB EVAPORATION FROM LIQUID-IRON

The evaporation kinetics of Zn and Pb from liquid iron at 1600 degrees C were studied under argon pressure 0.1 to 50 bar in an induction fur nace. It was found that the limiting step of evaporation under p(Ar) < 1 bar is diffusion in the melt, Diffusion in the gas phase becomes ra te-determining with increasing argon pressure. The phase boundary reac tion has no effect on the evaporation of Zn and Pb. The evaporation of Zn can evidently be reduced by increasing argon pressure above 1 bar, while the evaporation of Pb is not significantly effected by changes of argon pressure.