煤系高岭土制备碱性分子筛材料

Preparation of Basic Molecular Sieve Materials from Coal-measure Kaolin

本研究以煤系高岭土为原料、NaOH溶液为浸取液,先于800℃煅烧2h得到偏高岭土,再在全密封反应釜中通过偏高岭土和NaOH溶液(固液比1∶20)之间的水热反应制备碱性分子筛(Na8(AlSiO4)6(OH)2.2H2O)。并采用X-射线衍射仪(XRD)、傅立叶转换红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)和N2吸附脱附等测试手段对Na8(AlSiO4)6(OH)2.2H2O分子筛进行表征。结果表明,煤系高岭土经800℃煅烧后颗粒形貌不改变,平均尺寸2μm左右,碱浸取后变成分子筛微球;NaOH溶液的最佳浓度是4mol/l;Na8(AlSiO4)6(OH)2.2H2O分子筛具有狭缝状孔道,孔的形状和尺寸均匀,是一类典型的微孔-介孔分子筛材料。

The basic molecular sieve [Na8（AlSiO4）6（0H）2·2H2O] was synthesized in a sealed Teflon lined autoclave by hydrothermal reaction of NaOH solution and metakaolinites （solid/liquid= 1 ： 20） prepared by calcined coal-measure kaolin at 800℃ for 2h. Na8（AlSiO4）6（0H）2·2H2O molecular sieve was characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM）, High Resolution Transmission Electron Microscopy （HRTEM） and N2 adsorption and desorption isotherm plot methods. The results indicate that the shape of coalmeasure kaolin was not changed by calcined at 800℃ ; its average size was about 2μm and it was transformed to molecular sieve microspheres ; the best concentration of NaOH solution was 4mol/l; the pore channel of Na8（AlSiO4）6（0H）2·2H2O molecular sieve was long and narrow, but its shape and size were uniform, it was one type of micro-mesoporous sieve materials.