Theoretical simulation and experimental study of hydrolysis separation of SbCl3 in complexation-precipitation system

The theoretical simulation and verified experiments on metal separation in a Sb3+-OH−-Cl− complexation-precipitation system involving hydrolysis-precipitation reactions of SbOCl, Sb4O5Cl2 and Sb2O3 were carried out. The equilibrium concentration of [Sb3+]T was obtained by calculation and verified by experiments. The precipitates SbOCl, Sb4O5Cl2 and Sb2O3 were analyzed through the equilibrium concentration of Sb3+ in the solution and the ΔrGΘm of transformation reactions of these materials. It is found that the concentration of [Sb3+]T in verified experiments was larger than the theoretical value, where the theoretical minimum concentration of [Sb3+]T was 10−10.92 mol/L at pH value of 4.6 and the minimum concentration obtained from the verified experiment was about 10−3.8 mol/L at pH value of 5.1. Different precipitates can be obtained at certain pH. The SbOCl cannot be obtained both in theoretic calculations and in verified experiments, while the Sb8O11Cl2·H2O was generated in the experiment.