针对我国现行火法炼锑工艺所存在的冶炼温度高、流程长和低浓度SO2烟气污染严重等弊端,提出一种新的火法炼锑工艺——硫化锑精矿低温熔盐熔炼。采用单因素实验法分别考察熔盐组成、熔炼温度、熔炼时间、熔盐量及固硫剂ZnO加入量对金属锑直收率和粗锑品位的影响。获得优化实验条件如下:熔炼温度为850℃,w(Na2CO3)/w(固体物)=5:1,w(Na2CO3)/w(NaCl)=0.75,w(ZnO)/w(理论量)=1.0,反应时间为1 h。在此优化条件下进行综合扩大试验,锑的直收率为84.42%,所得粗锑品位为86.66%。
In view of serious shortcomings existing in current antimony pydrometallurgical process such as complex operation,high smelting temperature and low concentrations SO2 fume pollution,a low-temperature molten salt smelting process to directly produce antimony was proposed in this work.Effects of molten salt composition,smelting temperature,reaction time,salt amount,and ZnO addition on the molten salt smelting of stibnite concentrate were investigated.The optimum conditions is determined as follows: w(Na2CO3)/w(NaCl)=0.75,temperature 850 ℃,reaction time 1 h,w(Na2CO3)/w(solids)=6:1,w(ZnO)/w(theory)=1.0.Under above-mentioned optimum conditions,the average direct recovery ratio of antimony is 84.42%,and the average grade of crude antimony is 86.66%.