选矿废水的混凝沉淀处理及回用工程设计

THE ENGINEERING DESIGN OF ORE-WASHING WASTEWATER TREATMENT AND ITS REUSE BY COAGULATION-SEDIMENTATION

在对广西兴安钨矿选矿废水水质分析的基础上 ,分别选择三氯化铁、精制硫酸铝、三氯化铝、聚合氯化铝和聚丙烯酰胺 (PAM)作混凝剂进行了混凝沉淀试验。综合考虑处理效果即出水COD和浊度以及成本 ,三氯化铁最为合适 ;三氯化铁的最佳投加量为 12 0mg/L ,出水水质符合国家污水排放标准并能回用。最后提出了工程设计方案 ,此方案既防止了废水对环境的潜在污染 ,又解决了枯水期选矿用水不足的问题。

In order to protect environment and prevent pollution of water body, Xingan Tungsten Mine entered the list of the project whose wastewater should be treated in limited time. On the basis of ore washing wastewater quality analysis, the ore separating wastewater was coagulated with ferrous chloride, refined aluminium sulphate, aluminium chloride, polyaluminium chloride and polyacrylic amide (PAM), respectively. The results have shown that ferrous chloride was the best coagulant according to coagulating results, i.e., removal of COD and turbidity, and costs. The optimum value for dosing ferrous chloride was 120 mg/L. The treated water was suitable to meet the requirements of national wastewater discharge standard and then give reuse. Finally, the engineering design involved wastewater treatment and reuse by coagulation-sedimentation is proposed. In this way, the environmental pollution caused by wastewater may be prevented and the problem of water shortage in the ore-separating process during the dry season is solved as well.