用蒸汽相法合成4A沸石

Synthesis of 4A-zeolite with vapor phase transport process

研究了采用蒸汽相法合成4A沸石的工艺过程,考察了硅铝摩尔比、水钠摩尔比和晶化时间等不同条件的变化对所生成样品钙交换能力的影响。通过采用X衍射测定样品的结晶度、采用激光粒度仪测定样品的粒度分布和采用EDTA络合滴定法测定样品的钙交换能力,对4A沸石的结构和性能进行了研究。结果表明在较优合成条件(SiO2/Al2O3摩尔比为1 9/1 0,Na2O/SiO2摩尔比为3/1,H2O/Na2O摩尔比为30～40/1,晶化汽温100℃)下,样品粒度分布<4μm(>85%),钙交换能力(以CaCO3计)为300mg/g(沸石),而且样品的粒度分布较窄,能够满足洗涤剂助剂的要求。

The synthesis of 4A-zeolite with vapor phase transport process was studied and the effects of various conditions,such as SiO2/Al2O3 mol ratio,H2O/Na2O mol ratio,crystallization time etc., on the calcium exchanging capability of the product were investigated.Through the determination of the degree of crystallization by X-ray diffractometry,the determination of particle size distribution by laser granularity meter;and the determination of calcium exchanging capability by EDTA complexometric titration.The structure and performance of 4A-zeolite were examined.Experimental results show that,under optimal conditions(SiO2/Al2O3 mol ratio=19/10,Na2O/SiO2 mol ratio=3/1,H2O/Na2O mol ratio=30～40/1,vapor phase transport crystallization temperature 100 ℃),the particle size distribution of the product sample can achieve:<4 μm,(>85 %,with narrow peak),Ca exchanging capability>300 mg/g(4A-zeolite),which satisfies the requirements for using as a detergent builder.