Electrochemically Converting Liquid Cu2S-Sb2S3 to Liquid Cu2Sb and Sulfur in Molten Salt at 730 °C

Conventional sulfide metallurgy suffers from SO x gas emission and high energy consumption, owing to the multiple-step extraction processes and high temperatures that are above the melting point of the extracted metals. Herein, liquid Cu 2 Sb alloy can be directly electrochemically extracted from the liquid Sb 2 S 3 -Cu 2 S with no sulfide oxides emission in eutectic NaCl-KCl molten electrolyte at 730 °C. The use of Sb 2 S 3 decreases the melting point of Cu 2 S and the Sb decreases the melting temperature of Cu. The Sb 2 S 3 -Cu 2 S mixture experiences three stages in the electrochemical desulfurization process: the insertion of Na + into liquid sulfides, the removal of S 2− and metallization, and finally the formation of uniform liquid Cu 2 Sb alloy. The Sb 2 S 3 -Cu 2 S can be completely electro-converted into Cu 2 Sb at 2.6 V for 6 hours. This study provides a straightforward and environmentally friendly route to electro-synthesize liquid alloys from their molten sulfide minerals. Graphical Paving the way : The conventional pyrometallurgical route extracts copper and antimony metals from their sulfide minerals through roasting, smelting, and refining processes. These steps call for high temperature and generate SO 2 and CO 2 , which will cause intense energy consumptions and pollution. This paper paves a green electrochemical route to prepare liquid Cu 2 Sb alloy from their molten sulfides at 730 °C without SO x (CO 2 ) emissions.