工业废盐酸浸出拜耳赤泥中铁、铝的试验研究

Experimental Research on Leaching of Iron,Aluminum from Bayer Red Mud by Using the Industrial Waste Hydrochloric Acid

研究了工业副产废盐酸常压浸出拜耳法赤泥中铝、铁的过程。考察了盐酸浓度、浸出温度、浸出时间和液固比对氧化铁、氧化铝浸出率的影响。通过试验得出了较佳浸出工艺条件:盐酸浓度25%、酸浸温度90℃、酸浸时间60 min、液固比6∶1。在此条件下,铁的浸出率为92.51%,铝的浸出率为90.12%。各因素对氧化铝氧化铁浸出率影响大小为:酸浸反应温度>盐酸浓度>反应时间>液固比。同时,利用硫酸铁作为除钙剂对赤泥盐酸浸出液进行脱钙处理,Ca^(2+)一次脱除率达83.3%。研究成果为低浓度工业废盐酸和贵州拜耳赤泥的处置与利用提供了理论依据和技术参考。

The leaching process of aluminum and iron from Bayer red mud was studied by using the industrial byproduct dilute hydrochloric acid under atmospheric pressure.The effect of the concentration of hydrochloric acid,reaction temperature,reaction time and lquid-solid ratio of hydrochloric acid to red mud on leaching rate of iron oxide and alumina was investigated.Through tests the leaching conditions are established： the concentration of hydrochloric acid is 25%,the reaction temperature is 90 ℃,the reaction time is 60 minutes and the liquid-solid ratio of hydrochloric acid to red mud is 6 ∶ 1.With the optimum technical condition,the leaching ratio of alumina and iron oxide and alumina can reach 92. 51%and 90. 12%,respectively.The influence degree of each factor on the leaching ratio was reaction temperature,the concentration of hydrochloric acid,reaction time and the liquid-solid ratio.Meanwhile,Through the use of ferric sulfate as decalcifying agent for the removal of calcium of leaching solution,one time removal rate of Ca^2＋ reached 83. 3%. The research can provide theoretical basic and technical reference for disposal and utilization of the low concentration of industrial waste hydrochloric acid and Guizhou Bayer red mud.