高炉渣制备聚硅酸硫酸铝铁混凝剂

以高炉渣为原料,分别采用酸浸及碱浸-酸化工艺得到铁、铝离子及聚硅酸,再将铁、铝离子引入聚硅酸制得聚硅酸硫酸铝铁(PSAFS)混凝剂。考察了PSAFS的聚合条件对焦化废水混凝效果的影响,并与市售混凝剂进行了对比。实验结果表明:PSAFS的最佳制备条件为n(Al+Fe)∶n(Si)=0.53,混凝剂p H=1,熟化时间0.5 h,熟化温度60℃;PSAFS加入量为4 m L/L时,混凝效果最好,对焦化废水的浊度和COD的去除率分别达到98.9%和74.5%;PSAFS的性能优于市售的3种混凝剂。

Preparation of Polysilic Aluminum Ferric Sulfate Coagulant from Blast Furnace Slag

Polysilic aluminum ferric sulfate （PSAFS） coagulant was prepared using aluminum ion,iron ion and polysilicic acid,which were obtained from blast furnace slag by acid leaching and alkaline leaching - acidification processes. The effects of the PSAFS polymerization conditions on coagulation of coking wastewater were studied and compared with those of commercial coagulants. The experimental results show that the optimum preparation conditions are as follows：n（Al+Fe）∶n（Si） = 0.53∶1,coagulant pH = 1,aging time 0.5 h,aging temperature 60 ℃. When the dosage of PSAFS is 4 mL/L,the coagulation effect is the best with 98.9% and 74.5% of turbidity and COD removal rate of the wastewater respectively. The performance of PSAFS is better than those of 3 commercial coagulants.