Physico-chemistry in distillation process of BiCl3 -HCl-H2 O system

摘要

The gas-liquid equilibrium and evaporation behaviors of HCl and H2O in the distillation process of the BiCl3-HCl-H2O ternary system were investigated. With increasing content of BiCl3, the quasi-azeotropic point moves toward the low acidity and high temperature. The evaporation law of HCl and H2O in low-acidity BiCl3 solution was summarized. The residue phases were studied as well. The results show that the residue phases vary with the distillation temperature, namely BiCl3 and BiCl3*xHCl at low temperature and BiCl3 and BiOCl exist at higher temperature. The causes for the formation of different residue phases were discussed.