粉煤灰制备高纯度X型沸石及其对含铅废水处理的研究

采用经碱熔融-离心提取处理的粉煤灰为原料，经水热反应法研究合成高纯度X型沸石的过程，探讨了碱灰比、焙烧温度对硅铝熔出量的影响，研究了碱度、陈化时间、晶化时间与硅铝比对合成的影响以及其对含Pb2＋废水的吸附性能。结果表明：碱灰比为2．3∶1，焙烧温度为680℃时可获得最佳的硅铝熔出量；当SiO2／Na2 O＝1（摩尔比），SiO2／Al2O3＝3．5（摩尔比），陈化时间为5 h，晶化时间为16 h时可获得高纯度X型沸石。合成沸石表现出对含Pb2＋废水较强的吸附能力，在投加0．23 g／100 mL含Pb2＋500 mg／L溶液中，调节pH值为5，常温下30 min，Pb2＋去除率可达99．6％；吸附容量达到了216．8 mg／g。

Removal of Pb2+from Waste Water with High Purity Zeolite X Synthesized by Coal Fly Ash

High purity zeolite X was synthesized by hydrothermal method with coal fly ash pretreated by alkaline fusion and centrifugal extraction , the effects of alkali/ash and roasting temperature on the quantity of silicon aluminum dissolution were discussed , the influences of alkalinity , aging time, crystallization time and Si/Al ratio on synthesis zeolite were investigated and the adsorption performance of Pb2+-containing waste water has been researched .The results showed that the highest silicon aluminum dissolution quantity obtained at 680 ℃, alkali/ash =2 .3 and the high purity zeolite X synthesized at SiO2/Na2O=1, SiO2/Al2O3 =3.5, 5 h aging and 16 h crystallization.The obtained zeolite X showed fast adsorption to Pb 2+-containing waste water .The removal rate of Pb 2+can be up to 99 .6%for 30 min at the room temperature in the condition of pH =5, adding 0.23 g/100 mL in 500 mg/L Pb2+solution. The adsorption capacity of zeolite X was 216.8 mg/g.