含锡铁精矿CO还原分离锡铁的行为研究

Research on Separating Tin and Iron from Tin-bearing Iron Concentrate by CO Reduction

以含锡铁精矿(Sn:0.26%,TFe:65.7%)为研究对象进行还原焙烧。在分析还原焙烧过程中锡、铁氧化物行为的基础上,重点研究了预氧化、焙烧温度、焙烧时间以及还原气氛(气相中CO含量)对锡脱除效果的影响。实验结果表明,锡的脱除主要发生在弱还原气氛焙烧阶段。在优化条件下(焙烧温度925～950℃,焙烧时间30 min,还原介质中CO体积浓度为40%～50%),球团矿中锡的残余量为0.031%,锡的挥发率达到88.88%。

The experiment of reduction roasting was carried out for tin-bearing iron concentrate （ Sn ： 0.26%, TFe ： 65.7% ）. Based on the analysis of behavior of tin and iron oxides during reduction roasting, the effects of pre-oxidation, roasting temperature and roasting time, as well as reduction atmosphere（ CO content in gas phase） on tin removal were investigated emphatically. The experimental results showed that the tin removal principally occurred in weak reduction roasting stage. Under the optimum conditions that the roasting temperature was 925- 950℃ , roasting time was 30 rain and the volume concentration of CO in reduction medium was 40% - 50% , the residual content of tin in the pellets was O. 031% and the volatilization rate of tin reached 88.88%.