Physico-chemistry in distillation process of BiCl_3-HCl-H_2O system

摘要

The gas-liquid equilibrium and evaporation behaviors of HCl and H 2O in the distillation process of the BiCl 3-HCl-H 2O ternary system were investigated. With increasing content of BiCl 3, the quasi-azeotropic point moves toward the low acidity and high temperature. The evaporation law of HCl and H 2O in low-acidity BiCl 3 solution was summarized. The residue phases were studied as well. The results show that the residue phases vary with the distillation temperature, namely BiCl 3 and BiCl 3·xHCl at low temperature and BiCl 3 and BiOCl exist at higher temperature. The causes for the formation of different residue phases were discussed.