Solubility of Sb in binary Na2CO3–NaCl molten salt

Abstract

The interaction between molten Na2CO3–NaCl salt and Sb and the solubility of Sb in molten salt were investigated in the temperature range of 700–1000 °C. The results show that the dissolution equilibrium of Sb in molten salt can be achieved in 3 h, and the amount of Sb dissolved in the melt decreases as the viscosity decreases. The solubility limits in an eutectic mixture were determined as 5.42%, 2.42%, 0.75% and 0.68% at 700, 800, 900 and 1000 °C, respectively. A high temperature and appropriate content of NaCl will decrease the dissolution of Sb. The insoluble Sb was collected at the bottom of molten salt. The Sb dissolved on the surface of the molten salt is easily oxidized, whereas the Sb dissolved inside the molten salt is randomly distributed in terms of the form of metal Sb.