China Nonferrous Metallurgy

Jamesonite accounts for 30% to 40% of China s total antimony resources, making it a crucial mineral resource. Due to its high sulfur content, the sulfur-containing flue gas generated during smelting increases subsequent treatment costs. This paper proposes a low-temperature reduction smelting process for jamesonite to achieve sulfur fixation. Using ZnO as the sulfur fixative, carbon powder as the reducing agent, and Na₂CO₃ molten salt as the smelting medium, the study investigates sulfur fixation during the low-temperature reduction smelting of sulfur-bearing galena. Thermodynamic analysis indicates that both antimony sulfide and lead sulfide can undergo reduction reactions with zinc oxide and carbon powder at lower temperatures in a sodium carbonate system. During these reactions, Na₂CO₃ provides a liquid-phase reaction environment, optimizing the reaction pathway and enhancing reaction rates, thereby promoting more complete and thorough low-temperature sulfur fixation. Single-factor experiments demonstrate that under the following conditions: 1.224g of jamesonite, 7.5g of anhydrous sodium carbonate (reused in subsequent cycles), zinc oxide dosage at 1.25 times the theoretical amount, temperature of 900℃, and reaction time of 60minutes, the sulfur fixation rate reaches 97.2%, with lead and antimony recovery rates achieving 92.6% and 89.3%, respectively. TG and XRD analyses validated the thermodynamic analysis and experimental results, indicating that under optimal experimental conditions, the sulfur fixation rate reached its maximum. Sulfur in the minerals was solidified as ZnS and Na₂S, with significant amounts of lead-antimony alloy formed. SEM analysis revealed spherical particles of lead-antimony alloy in the product, columnar structures of PbO and Sb₂O₃, aggregated impurities such as sodium salts, and the presence of partial slag. This research provides theoretical support for low-temperature clean smelting of jamesonite.