粉煤灰水热合成方沸石及其表征

Hydrothermal Synthesis of Zeolite from Coal Fly Ash and Its Characterization

以粉煤灰为原料,通过水热反应合成了粉煤灰沸石,并通过粉末X-射线衍射(PXRD)、扫描电镜(SEM)、红外光谱分析(FTIR)、热重和差式扫描量热分析(TG/DSC)等手段对产物进行了分析表征。结果表明,在实验配比条件下,190℃水热反应12~24 h,合成产物均为纯度较高的方沸石,分子式为Na[Al Si_2O_6]·H_2O。PXRD和SEM表明合成产物有典型的方沸石结构和形貌特征,FTIR结果符合方沸石红外图谱,TG/DSC表明产品具有较好的热稳定性,通过DFT方法,得到沸石孔容积为0.028 cm^3/g,比表面积为6.926 m^2/g,表观主孔径约为3 nm,BET等效比表面积为11.194 m^2/g。

Using fly ash as raw materials,fly ash zeolite was synthesized by hydrothermal reaction,and the products were characterized by powder X-ray diffraction（ PXRD）,scanning electron microscopy（ SEM）,infrared spectrum analysis（ FTIR）,thermogravimetric and differential scanning calorimetry analysis（ TG/DSC）. The results show that under the condition of experimental proportion,the zeolite with high purity can be synthesized by hydrothermal reaction at 190 ℃ for 12-24 h,and the molecular formula is Na[Al Si_2 O_6]· H_2 O. PXRD and SEM showed that the synthetic product has the typical structure and morphology characteristics of analcime,FTIR results are consistent with the IR spectra of analcime,TG/DSC showed that the product has good thermal stability,and the sample has pore volume of 0. 028 cm^3/g,specific surface area of 6. 926 m^2/g,apparent pore size of 3 nm by DFT method,and the equivalent BET surface area is 11. 194 m^2/g.