钽铌冶炼铁泥制备聚硅酸硫酸铁絮凝剂及其应用

Preparation of poly-ferric silicate sulfate by using iron sludge from Tantalum and Niobium smelting process and its application

本文以Fenton试剂法处理钽铌冶炼废水产生铁泥作为聚硅酸硫酸铁制备铁源,在不同的ω(SiO_2)、pH值、n(Fe)/n(Si)条件下优化制备了聚硅酸硫酸铁絮凝剂,并进行钨铋多金属矿选矿废水及高浊度模拟废水处理.研究结果表明:在ω(SiO_2)=1.00%、pH=3.00、n(Fe)∶n(Si)=1∶1的适宜条件下制得的聚硅酸硫酸铁絮凝剂效果最佳.在0.10%(体积分数)投加量下搅拌2 min,钨铋选矿废水浊度去除率达99.9%,COD去除率达76.8%,废水中Pb和As去除率分别达98.8%和97.2%,Be去除率几乎达100%,处理后废水浊度由319 NTU降至0.32 NTU、COD含量由322 mg·L^(-1)降至74.7 mg·L^(-1),废水中Pb和As质量浓度分别由7.89、1.03 mg·L-1降至0.09、0.03 mg·L^(-1),未检出Be;高浊度模拟废水浊度去除率达98.5%,浊度由716 NTU降至10.7 NTU.处理后废水达到《污水综合排放标准》(GB 8979—1996)一级标准.

Poly-ferric silicate sulfate was prepared with Fenton reagents using iron sludge from Ta and Nb smelting wastewater,and the preparation condition was optimized by using different ω（SiO2）,pH values and n（Fe）/n（ Si）. The treatment of wastewater from W and Bi containing multimetal ore dressing process and that from high turbidity containing bentonite was then carried out using the poly-ferric silicate sulfate. The results showed that the optimized condition of poly-ferric silicate sulfate preparation were ω（ Si O2） = 1.00%,p H = 3.00,n（ Fe） ： n（ Al） = 1∶1. When 0.10%（ volume ratio） of poly-ferric silicate sulfate was added to the wastewater from W and Bi containing multi-metal ore dressing process,the removal rratio was 99.9% for the turbidity after 2 min,76.8%,for COD,98.8% and 97.2% for Pb and As,and almost 100% for Be. The concentrations of turbidity and COD in wastewater decreased from 319 NTU and 322 mg·L^（-1） to 0.32 NTU and 74.7 mg·L-1,while those of Pb and As decreased from 7. 89 mg·L^（-1） and 1. 03 mg·L^（-1） to 0. 09 mg·L^（-1） and0.03 mg·L^（-1） and Be was below the detection limit,respectively. When 0. 10%（ volume ratio） ofpoly-ferric silicate sulfate was added to the high turbidity simulated wastewater containing bentonite,the removal rate of turbidity exceeded 98. 5% after 2 min,and the concentration decreased from716 NTU to 10.7 NTU. After coagulation,the quality of wastewater from W and Bi containing multimetal ore dressing process and that of high turbidity containing bentonite both meet the first grade of the National Integrated Wastewater Discharge Standard（ GB 8978—1996）.