Application of MIVM for Sn-Zn System in Vacuum Distillation

The activities of components of Sn-Zn system were predicted based on the molecular interaction volume model (MIVM). The separation coefficients and the vapor-liquid phase equilibrium of Sn-Zn system were also predicted using the MIVM. The predicted results indicated that the content of tin in the vapor phase was 0.000052 wt pct, while in the liquid phase, it was 99.98 wt pct at 1173 K (900 degrees C). Experimental investigations into the separation of Sn-Zn alloy by vacuum distillation were carried out for the proper interpretation of the predicted results. The effects of vacuum level (15 to 200 Pa), distillation temperatures [873 K to 1273 K (600 degrees C to 1000 degrees C)], and soaking time (20 to 60 minutes) were studied. The experimental results indicated that the content of tin in the vapor phase was 0.001 wt pct, while in the liquid phase, it was 99.98 wt pct at 1173 K (900 degrees C). The experimental results match well with the predicted data, suggesting that the MIVM is a suitable model for Sn-Zn system. (C) The Minerals, Metals & Materials Society and ASM International 2014