赤泥中铝铁的提取及聚硅酸铝铁固体絮凝剂的制备

利用拜耳赤泥和盐酸为主要原料,制备出方便保存的聚硅酸铝铁固体絮凝剂。探讨了赤泥中铝铁的最佳提取工艺,如盐酸浓度、盐酸用量、反应温度,反应时间等。结果表明,盐酸浓度8 mol/L,反应温度85℃,盐酸与赤泥的液固比为6∶1,反应时间为2.5 h,铝铁溶出率较理想。制得的聚硅酸铝铁对废水处理效果优于市售聚硅酸铝铁,且絮体较大、致密、沉降速度快,对COD去除效果达98.6%,色度去除率达87%。

The Extraction of Aluminum and Iron from Red Mud and the Preparation of Poly - Silicic - Aluminum - Ferric Flocculant

The solid poly -silicic - aluminum - ferric （PSAF） flocculant which was obtained using the red mud producted by bayer mothod and hydrochloric acid as the main materials. The extracted conditions of aluminum - ferric were optimazed, such as concentration and dosage of hydrochloric acid, reaction temperature, reaction time. The result show that the optimal conditions are as follows ： the concentration of hydrochloric is 8 tool/L, the reaction temper- ature is 85~C ,the ratio of hydrochloric acid to red mud is 6：1 and the reaction time is 2.5 h. The experiment dams indi- cated that our prepared PSAF flocculant has advantages over the commercial PSAF flocculant in effect of colority remov- al, and after treatment, the floccule was bigger, compacter and had a higher sedimentation velocity than the commercial flocculant. Over 98% of COD and 87% of colority are removed by poly -silicic - aluminum - ferric flocculant.