One-step electrolytic reduction desulfurization of Sb2S3 in different molten salts
(School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract: A comparative analysis of different molten salt systems was conducted, including NaCl-KCl, NaCl-CaCl2, NaCl-Na2CO3, NaCl-KCl-CaCl2, and NaCl-KCl-Na2CO3. The phase diagrams, thermal stability, and solubility of Sb2S3 in molten salt systems were investigated. Based on the distribution of the element antimony, current efficiency, energy consumption, and the characterization of the residue, the most suitable molten salt for the electrical reduction of Sb2S3 was verified. The results show that all molten salt systems have good thermal stability and can realize the electrolytic reduction of Sb2S3. The system with CaCl2 is not conducive to the dissolution of Sb2S3, and the system with Na2CO3 can react with Sb2S3. In addition, the current efficiency of the NaCl-KCl system is the highest (75.68%), and the energy consumption ratio is the lowest (2.18 kW·h/kg).
Key words: antimony smelting; molten salt electrolysis; Sb2S3; eutectic system