| Na-X and Na-A two kinds of zeolites are widely used in wastewater treatment,gas adsorption and separation,catalysis and other fields and the demands increases year by year.The conventional hydrothermal methods for synthesis of these two zeolites processes for a long time and high energy consumption,so it is meaningful to study a rapid synthesis method.As a kind of solid waste,fly ash has caused serious natural environmental disasters due to its accumulation in large quantities in recent years,which has attracted widespread attention.At present,there are many cases of comprehensive utilization of fly ash,but most are very simple and less economic,so the high-valued use of fly ash has not been realized actually.Fly ash mainly consists of SiO2 and Al2O3 with low SiO2/Al2O3 ratio,which well fits for the synthesis of Na-X and Na-A.In this paper,the method for rapid preparation of Na-X and Na-A were studied firstly by using pure chemical reagents.Then the process was applied in the conversion of fly ash to obtain high-valued zeolites Na-X and Na-A.(1)Zeolites Na-X and Na-A with high purity,high crystallinity,good morphology and large specific surface area were successfully synthesized from pure chemicals by conventional hydrothermal method and rapid synthetic method at higher temperature.By changing the experimental conditions,the influences of SiO2/Al2O3 ratio,alkali/SiO2 ratio,H2O/SiO2 ratio and other factors on the synthesis were studied.Na-X and Na-A were characterized by means of XRD,SEM,TEM,BET and so on,and the optimal synthesis process conditions are obtained.(2)The optimized conditions had been successfully applied in the conversion of fly as to zeolite.Using fly ash as feed,the effects of factors on synthesis was also investigated and the optimized conditions were obtained at higher temperature.Zeolites Na-X and Na-A with high purity and crystallinity were obtained only in about 1h. |
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