NaA型小晶粒沸石分子筛的研磨制备

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3 μm、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0.98 μm、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。

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

In order to investigate the method to produce NaA molecular sieve in large scale,the fine-crystal NaA molecular sieve was prepared by grinding method using NaA zeolite as raw materials and NaCl as grinding aids.The phase composition,morphology,particle distribution and surface area of NaA molecular sieve before and after grinding were characterized by SEM,BET,and Laser Particle Size Analyzer,and Cd2+ exchange capacity was determined.The results showed that the particle size of NaA molecular sieve was decreased from 3 μm to 0.98 μm,the surface area was increased from 12.306 m2/g to 27.997 m2/g,and Cd2+ exchange capacity was enhanced from 294 mg/g to 352 mg/g after grinding under conditions of rotating speed 400 r/min,w(NaCl)∶w(NaA) of 12∶1,mass ratio between ball and powder 7∶1 for 7 h.Therefore,the dry grinding method is a novel method for mass production of NaA molecular sieve,with easy operating and low cost.