拜尔法赤泥精细还原实验研究

PRECISE REDUCTION EXPERIMENT STUDY OF BAYER RED MUD

用精细还原方法对拜尔法赤泥进行了处理,以铁氧化物的还原度为考察指标,取其影响因素及变化范围为:赤泥颗粒平均尺度1.24~2.43μm、气态还原剂CO-H2、还原温度700~1 000℃、还原时间2~4 h。研究结果表明,还原温度对还原度的影响最为显著,其他因素影响不显著;最佳还原工况为:还原温度1 000℃、赤泥颗粒平均尺度1.236μm、气态还原剂为H2,还原时间4 h;在最佳工况条件下进行还原,还原度高达99%以上;精细还原过程中赤泥颗粒间未发生烧结,有利于采用物理方法将铁元素与其他杂质元素进一步分离;分离铁以后的尾渣可用于炼钢用脱硫渣。

The reduction experiments of Bayer red mud were carried out by using precise reduction method. The indicator of the experiment was the reduction rate of iron oxide. Its impact factors and changing scopes were that the average size of the red mud particles of 1. 24 to 2. 43 μm,gaseous reducing agent CO-H2 reduction temperature of 700 ~ 1 000 ℃ and the reduction time of 2 ~ 4 h. The results showed that the effect of the reaction temperature on the reduction rate was significant,and other factors were not; the optimal conditions for the reduction rate were fine grinding red mud particle average size of 1. 236 μm,gaseous reducing agent of H2,reduction temperature of 1 000 ℃,and reduction time of 4 h; under the optimal condition,the reduction rate was higher than 99%; during the precise reduction process,no sintering appeared between particles,making it possibile to separate the iron from other elements by physical method; the tailing could be taken as the desulfurization slag for steel after the separation of iron.