水热体系合成NaA/X复合沸石

Synthesis of NaA/X Composite Zeolites in Hydrothermal Reaction System

在无模板剂条件下,采用水热反应体系合成NaA/X复合沸石,研究了原料配比及凝胶化条件对NaA/X复合沸石合成的影响。结果表明,该反应体系钠的优化配比为n(SiO2):n(Al2O3)=2.8,反应的适宜碱度条件为:n(H2O):n(Na2O)=25～30、n(Na2O):n(SiO2)=1.6～3.0,碱度过高或过低均会导致X型沸石的消失。产物为复合沸石,粒径为150nm,分散度较好。产物的钙离子交换能力达到300mg/g,镁离子交换能力优于纯4A、X及高铝P型沸石。

The NaA/X composite zeolites were successfully synthesized under hydrothermal treatment without template. On the basis of many experiments, this paper discusses the effect of composition of raw material and the condition of gel formation on the synthe- sis of NaA/X composite zeolites according to X-ray diffraction analysis. Investigation shows that the optimum n（SiO2）：n（Al2O3） is 2.8 in this hydrothermal reaction system. The proper basicity conditions are molar ratios n（H2O）：n（Na2O）= 25-30 and n（Na2O）：n（SiO2）= 1.6-3.0. Scanning electron microscope analysis shows that the particle size of the as synthesized composite zeolite was uniform of about 150 urn. The calcium ion exchange capacity （based on CaCO3/anhydrous zeolite） of the products was 300 mg/g, the magnesium ion exchange capacity of the products was much better than zeolite 4A, X and high aluminum P zeolites.