摘要
以高岭土微球为硅源和铝源,采用水热晶化法在高岭土微球上原位合成K-Na L沸石,考察了钾钠比、碱量、铝量、硅量和水量等因素对K-Na L沸石合成的影响,并采用XRD和SEM对合成的产品进行表征和形貌观察.结果表明:凝胶组成基本配比为n(K2O+Na2O)∶n(Al2O3)∶n(SiO2)∶n(H2O)=4.2∶1.0∶15∶210,当钾钠摩尔比n(K2O)∶n(Na2O)=7∶3时合成L沸石的相对结晶度最高;保持钾钠摩尔比为7∶3,分别改变碱量、铝量、铝量和水含量,当3.3<x1<4.8时,K-Na L沸石的相对结晶度随着碱量升高而增大,当x1>4.2以后结晶度升高速率降低;相对结晶度随着Al2O3的增多先升高后降低,在x2=1.4时结晶度达到最高;硅源的性质对K-Na L沸石的影响较高,只有在9<x3<18之间才能合成出K-Na L沸石;K-Na L沸石的相对结晶度随着水含量的升高而降低,当x4>310时无K-Na L沸石生成.
In the study,zeolite K-Na L is in-suit synthesized through hydrothermal crystallization methods on kaolin microspheres used as the silica source and aluminium source.This paper studied the effects of different influential factors,such as the molar ratio of n（K2O）：n（Na2O）,alkalinity,Al2O3,SiO2 and H2O on the synthesis of zeolite K-Na L by univariate analysis experiment.The crystal phase of the as-prepared zeolites samples were characterized by X-ray diffraction（XRD） and scanning electronic microscopy（SEM）.It＇s found that the relative crystallinty of zeolite K-Na L can reach to the highest when the molar ratio of n（K2O）：n（Na2O） is 7：3;the base mole ration of the synthesis gel（maitain the molar ration of n（K2O）/n（Na2O）=7：3） is n（K2O＋Na2O）：n（Al2O3）：n（SiO2）：n（H2O）=4.2：1.0：15：210.It is concluded that the relative crystallinity of zeolite K-Na L increases with the increasing of alkalinity（3.3x14.8） and the increaseing ratio of the relative crystallinity gradually decreases（x14.2）;the relative crystallinity first goes up and then down with the increasing of the molar of Al2O3 and the relative crystallinity reaches to the highest when x2 equals to 1.4;the property of the silica souces has a great influence on the synthesis of zeolite K-Na L,and the zeolite K-Na L can only be synthesized when the x3 is in the region of 9x318;the relative crystallinity decreased with increasing of the molar of H2O and when x4 is greater than 310 zeolite K-Na L can not be synthesized.
出处
《郑州大学学报（工学版）》
CAS
北大核心
2010年第5期13-17,共5页
Journal of Zhengzhou University（Engineering Science）
