Nanometer A type molecular sieve preparation method

The invention relates to a process for preparing nano A type molecular sieve, including 3A, 4A and 5A molecular sieves, wherein silicon source and aluminum source are selected according the mol ratio of silicon : aluminum = 2:1, and 3-7 mol/L NaOH solution is added by the proportion of total solid weight of silicon and aluminum source : NaOH = 1:5-12, the process comprises the steps of, adding NaOH solution into silicon and aluminum sources, carrying out ultrasonic and microwave combination treatment for 10-150 minutes, controlling the temperature between 90-100 deg. C, filtering, scouring till pH=7-10, post-treating to obtain the nano A type amolecular sieve. 本发明涉及一种纳米A型分子筛的制备方法，包括3A、4A、5A分子筛。本发明选择硅∶铝摩尔比为2∶1的硅源和铝源，并按硅源铝源总的固体重量∶NaOH溶液＝1∶5-12的比例加入3-7mol/L的NaOH溶液，包括下列步骤：硅源，铝源加NaOH溶液，经超声波和微波联合处理10-150分钟，控制温度在90-100℃，之后冷却再过滤，洗涤至pH＝7-10，经后处理得到纳米A型分子筛。本发明主要引入了超声波和微波联合处理控制晶体长大。使晶体停留在纳米阶段无法长大。本发明所合成的纳米A分子筛的方法比常规水热法合成普通4A分子筛的方法能耗低、速度快、成本低廉、性能优异，有显著的经济效益。