Abstract:Address to poor adaptability of traditional smelting methods to raw materials like bismuth concentrate, especially unsuitable for low-grade bismuth concentrate, low comprehensive recovery rate of valuable metals, difficult treatment of low concentration SO2 produced by pyrometallurgy, and high cost, a new process for separating molybdenum, tungsten, sulfur and bismuth by pressure oxidation alkaline leaching was proposed using low grade bismuth polymetallic concentrate of Shizhuyuan as raw material. The effects of alkali dosage, time, temperature, total pressure and liquid-solid ratio on the leaching rate of molybdenum, tungsten, sulfur and bismuth were studied. Under the optimum conditions, the leaching rate of molybdenum, tungsten and sulfur is 99.73%, 90.81% and 97.69% respectively, while bismuth remains un-leached and is enriched in the slag, which realizes the efficient separation of molybdenum, tungsten, sulfur and bismuth in low-grade bismuth polymetallic concentrates.