(1. 中南大学 冶金与环境学院，长沙 410083；
2. 湖南工业大学 冶金工程学院，株洲 412007)
摘 要: 为解决我国当前火法炼铋厂普遍存在低浓度二氧化硫烟气污染、铋回收率低、试剂消耗大等问题，提出一种硫化铋精矿清洁冶金的工艺即硫化铋精矿还原造锍一步熔炼。采用单因素条件实验法考察添加剂用量、熔炼渣型、熔炼温度、反应时间等因素对金属铋直收率和渣含铋的影响，得出最佳熔炼工艺条件为：添加剂碳酸钠用量为精矿用量的20%(质量分数)、m(FeO)/m(SiO2)=1.0、m(CaO)/m(SiO2)=0.9、熔炼温度为1300 ℃、熔炼时间为2 h。在此最优条件下，金属铋直收率为85.86 %，渣含铋0.11%，固硫率达98.32%。同时，铅、钼、银在粗铋中的直收率分别达81.34%、80.95%、79.11%，说明新工艺的熔炼过程中对有价金属富集较好。
关键字: 硫化铋精矿；还原造锍；清洁冶金；一步熔炼
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. School of Metallurgy Engineering, Hunan University of Technology, Zhuzhou 412007, China）
Abstract:In order to solve the shortcomings of bismuth extraction in current bismuth smelters, such as environment pollution of sulfur dioxide, low direct recovery ratio of bismuth and large dosage of additive agent consumption, a direct process of reducing-matting smelting to treat bismuth sulfide concentrate, was proposed. The effects of parameters, including the dosage of additive agent, slag type, smelting temperature and time, on the direct recovery rate of bismuth and the content of bismuth in slag were investigated by single-factor experiments. After that, optimum conditions are obtained as follows: the mass fraction of soda to bismuth concentrate is 20%, m(FeO)/m(SiO2)=1.0, m(CaO)/m(SiO2)= 0.9, smelting temperature is 1300 ℃, and reaction time is 120 min, and the direct recovery rate of bismuth can reach up to 85.86%, the content of bismuth in slag is 0.11%, and the sulfur capture capacity is 98.32%. At the meantime, the direct recovery rates of lead, molybdenum and silver are 81.34%, 80.95% and 79.11%, respectively. The proposed process of new technology has good effect for enrichment of valuable metals.
Key words: bismuth sulfide concentrate; reducing-matting smelting; clean metallurgy; direct smelting
