粉煤灰制备聚合氯化铝铁及其对高岭土絮凝性能

Preparation of Polymeric Aluminum Ferric Chloride from Fly Ash and Adsorption Performance of Kaolin

以粉煤灰为原料,碳酸钠为助剂,经高温焙烧、盐酸酸浸、氢氧化钠聚合熟化,制备无机高分子聚合氯化铝铁(PAFC)絮凝剂,优化粉煤灰焙烧条件和PAFC絮凝剂的制备条件,将制备的PAFC絮凝剂产品用于处理高岭土废水。结果表明,活化剂碳酸钠与粉煤灰的质量配比为10:7,焙烧温度为800℃,焙烧时间为2 h,铝和铁离子的浸出率最高,分别为88.31%、53.66%。铝铁摩尔比为5.7:1,反应时间为1.5 h,制备的PAFC对高岭土废水浊度去除率最高,液体产品为黄褐色,烘干后所得固体产品为黄色粉末。对高岭土废水处理条件为p H值为7,PAFC液体絮凝剂投加量为1 mL/100 mL水样,慢速搅拌和静置沉降时间分别为45 min和60 min,形成的絮体粗大,沉降快,高岭土的浊度去除率为96.55%。

Using fly ash as raw material,sodium carbonate as an auxiliary agent,fly ash was roasted by high-temperature,hydrochloric acid leaching,and sodium hydroxide alkali solution polymerization to prepare inorganic polymer polymeric aluminum iron chloride(PAFC)flocculant.The calcination conditions of fly ash and the preparation conditions of PAFC flocculant were optimized,and the prepared PAFC flocculant was used to treat kaolin wastewater.The results show that mass ratio of activator sodium carbonate to fly ash is 10∶7,roasting temperature is 800℃and roasting time is 2 h,the leaching rates of aluminum and iron ions are the highest,which are 88.31%and 53.66%,respectively.The molar ratio of aluminum to iron is 5.7∶1,and the reaction time is 1.5 h,PAFC has the highest turbidity removal rate for kaolin wastewater,the liquid product is yellow brown and the solid product obtained after drying is yellow powder.When the reaction conditions of PAFC liquid flocculant on kaolin are pH value of 7,dosage of 1 mL/100 mL water sample,slow stirring time and settling time of 45 min and 60 min,respectively,the formation of coarse flocs with fast settling speed results in a turbidity removal rate of 96.55%for kaolin turbidity water.