CaCl2-AlCl3混凝沉淀法深度脱除钨冶炼废水中F-的研究

Removing F-in Tungsten Metallurgy Wastewater by CaCl2-AlCl3 Coagulation Precipitation

钨冶炼废水中F-的深度净化难是钨冶炼行业环保问题的技术瓶颈。本研究以钨冶炼典型的离子交换废水为对象,开发了CaCl2-AlCl3两步混凝沉淀法深度脱除废水中F-新工艺。考察了CaCl2浓度、AlCl3浓度、废水pH值等参数对废水除氟效果的影响。结果表明,在CaCl2浓度为1.0 g/L、废水pH值为12.0、反应时间为30 min的一段混凝沉淀最佳条件下,废水中F-浓度从80 mg/L降至34.6 mg/L;二段混凝沉淀在AlCl3浓度为2.5 g/L、废水的pH值为8.5、反应时间为30 min的最优条件下,废水中F-浓度进一步降至8.3 mg/L,达到了国家污水综合排放标准。该方法为钨冶炼废水深度除氟提供了新路径,可为钨冶炼行业的绿色环保提供技术支撑。

The deep removal of F-in tungsten metallurgy wastewater is the technical bottlenecks of environmental protection in tungsten metallurgy industry.The process of two-step CaCl2-AlCl3 coagulation and precipitation was proposed for deep removal of F-in the typical ion exchange wastewater from tungsten metallurgy.We also investigated the effects of CaCl2 concentration,AlCl3 concentration and pH value on fluoride removal.Results show that in the first stage,F-concentration in wastewater is decreased from 80 mg/L to 34.6 mg/L under the optimal defluoridation condition that the CaCl2 concentration of 1.0 g/L,wastewater pH of 12.0,and the reaction time of 30 minutes.In the second defluoridation stage,the F-concentration in wastewater is further reduced to 8.3 mg/L,meeting thenational integrated wastewater discharge standard,whenthe AlCl3 concentration reached 2.5 g/L,the wastewater pH value was 8.5,and reaction time lasted for 30 minutes.This method provides not only a new path for the deep F-removal from tungsten metallurgy wastewater but also technical support for the environmental protection in tungsten metallurgy industry.