Nanometer A type molecular sieve preparation method

Abstract

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.

Description

technical field [0001] The invention relates to a preparation method of A-type molecular sieve, in particular to a preparation method of nanometer A-type molecular sieve. Background technique [0002] Ordinary 4A zeolite molecular sieve has good surface adsorption capacity, its calcium exchange capacity is 5 times that of sodium tripolyphosphate (STPP), and it has anti-redeposition properties, which can provide a deposition surface for oils and dyes, and can avoid stains on fabrics Redeposition also has good thermal stability and dispersion performance, does not pollute the environment, is non-toxic and non-irritating to the human body. It is the preferred agent to replace STPP as hard water softener in synthetic detergents. Using 4A zeolite molecular sieves as detergent additives is an effective method for countries to produce low-phosphorus or phosphorus-free washing powder to solve environmental pollution problems such as excessive phosphorous in detergent wastewater and...

AI Technical Summary

Problems solved by technology

[0004] The traditional hydrothermal synthesis method can usually only obtain micron and submicron A-type molecular sieves, such as A-type molecular sieves with a particle size of 500nm, but cannot obtain molecular sieves with a particle size of 0.1-100nm

[0005] Zhou Zhou, Pan Weixiong, etc. in the article "Synthesis of Nano-4A Molecular Sieves" published in "Natural Gas Chemical Industry" on June 4, 2001, involved the synthesis method of nano-4A molecular sieves. The method uses ethyl silicate as the silicon source, isopropyl Aluminum alkoxide is the aluminum source, and the superfine oxide powder is prepared by the sol-gel supercritical drying method, and an appropriate amount of NaoH solution is added to synthesize nano-4A molecular sieves in an autoclave. The reaction synthesis method is complicated, the required equipment is expensive, and the reaction conditions are harsh. , the industrialization is difficult; the reaction time is long, the energy consumption is large, and the cost is high