(1. 河套学院 理学系，巴彦淖尔 015000；
2. 中南大学 冶金与环境学院，长沙 410083)
摘 要: 以Na2CO3-NaCl熔盐作为熔炼介质，提出以铁源为固硫剂的辉锑矿还原固硫直接熔炼，以解决当前炼锑工艺存在的温度高、流程长等缺点。结果表明：在Sb2S3-FeO-C反应体系中，Sb2S3的还原固硫反应分步进行，Sb2S3先与FeO发生交互反应生成Sb2O3和FeS，Sb2O3再被还原剂还原成金属锑。以Fe2O3为固硫剂的熔炼实验得到最佳工艺条件为： =1.0、碳粉质量为精矿质量的40%、熔炼温度850 ℃、熔炼时间60 min。在此最佳条件下，锑直收率为91.48%，粗锑品位94.31%。较传统火法炼锑工艺，熔炼温度降低300 ℃以上，熔炼过程中硫以FeS形式被固定，消除低浓度二氧化硫烟气的污染。
关键字: 锑冶金；熔盐熔炼；固硫机理；氧化铁渣
（1. Science Department, Hetao College, Bayannur 015000, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:In the views of the shortcomings in the current antimony smelting process which are high energy consumption and a long flow, a new process was proposed to smelt antimony directly from stibnite by reducing and sulfur-fixing reaction in NaCl-Na2CO3 molten salt. The reaction mechanism of reductive sulfur-fixation process of Sb2S3 was investigated. The results show that, for Sb2S3-FeO-C system, Sb2O3 and FeS are generated by sulfur-fixation reaction between Sb2S3 and FeO. And then, Sb2O3 can be consecutively reduced to Sb by reductive agent. The influencing parameters during smelting process are comprehensively investigated, including sodium salt content and composition, ferric oxide dosage, smelting temperature and smelting time. The optimum conditions are determined as follows: =1.0, mC:mconcentrate=40%, smelting temperature of 850 ℃ and smelting time of 60 min. Under the optimal smelting conditions, the average direct recovery rate of antimony and grade of crude antimony are 91.48% and 94.31%，respectively. Comparing to the traditional pyro-metallurgical process, the smelting temperature of present process is reduced at least 300 ℃. And sulfur is fixed in the form of FeS in the smelting process, so low concentration of SO2 emission could be avoided completely.
Key words: antimony metallurgy; molten salt smelting; sulfur-fixing mechanism; ferric oxide slag
