Electroreduction of Antimony Sulfide Enhanced by Nitrogen Bottom Blowing in Molten NaCl-KCl-Na2S

This work proposes a novel nitrogen bottom-blowing method to enhance mass transfer in the molten salt electrolysis process, improve current efficiency, and reduce electrolysis energy consumption. The effect of nitrogen agitation on the dissolution of Sb 2 S 3 and Sb was studied. The effects of nitrogen flow rate, electrolytic temperature, cell voltage, and pole spacing on the distribution behavior of Sb during constant piezoelectric reduction were investigated. The results show that nitrogen agitation can obviously accelerate the dissolution of Sb 2 S 3 . The current efficiency of the cathode reaches 92.76%, the energy consumption is 1.78 kWh kg −1 , and the grade of crude antimony is 98.5%. Compared to no nitrogen stirring, electrolytic current efficiency is improved by 19.87% and the energy consumption is saved by 20.89%. Furthermore, the appropriate flow rate of nitrogen accelerates the removal of sulfur from the reactor and avoids the formation of high-priced antimony compounds.