NaA型小晶粒沸石分子筛的研磨制备

Preparation of the Fine-crystal NaA Molecular Sieve by Grinding Method

为了探索NaA型小晶粒沸石分子筛的大规模生产方式,以偏高岭石水热转化法合成的NaA型沸石分子筛为原料、NaCl为助磨剂,采用研磨法进行了小晶粒NaA分子筛制备试验,用SEM、BET和激光粒度分析仪对研磨前后样品的形貌、粒度分布及比表面积进行了表征,并测定了研磨前后样品的钙离子交换容量。结果表明,在转速为400 r/min、NaCl与NaA质量比为12∶1、球料质量比为7∶1、研磨时间为7 h的条件下,可将标称粒径为3μm、比表面积为12.306 m2/g、镉离子交换容量为294 mg/g的NaA分子筛研磨至平均粒度为0.98μm、比表面积为27.997 m2/g、镉离子交换容量为352 mg/g的小晶粒NaA分子筛。因此,干法研磨工艺是小晶粒NaA分子筛大规模生产的易操作、低成本新工艺。

In order to investigate the method to produce NaA molecular sieve in large scale, the fine-crystal NaA molecu-lar sieve was prepared by grinding method using NaA zeolite as raw materials and NaC1 as grinding aids. The phase composi-tion, morphology, particle distribution and surface area of NaA molecular sieve before and after grinding were characterized bySEM, BET, and Laser Particle Size Analyzer, and Cd2＋ exchange capacity was determined. The results showed that the particlesize of NaA molecular sieve was decreased from 3 μm to 0.98 p,m, the surface area was increased from 12. 306 m2/g to27. 997 m2/g, and Cd2＋ exchange capacity was enhanced from 294 mg/g to 352 mg/g after grinding under conditions of rotatingspeed 400 r/min,w（NaC1） w（NaA） of 12 ： 1 ,mass ratio between ball and powder 7 ： 1 for 7 h. Therefore,the dry grindingmethod is a novel method for mass production of NaA molecular sieve,with easy operating and low cost.