METHOD FOR PRODUCING SYNTHETIC GRANULAR ZEOLITE OF PHOJAZITE TYPE Russian patent published in 2021 - IPC C01B39/20 B01J29/08 

FIELD: synthetic zeolite production.

SUBSTANCE: invention relates to the production of synthetic zeolite. A method for producing a granular zeolite without a binder with a faujasite structure is proposed. The method includes mixing the starting components, forming granules, drying them, thermal activation and hydrothermal crystallization in a liquid glass solution. Calcined kaolin, solid sodium hydroxide, silica gel are fed to the mixing stage to ensure the molar ratio Al₂O₃⋅2SiO₂:NaOH:SiO₂ = 1:2:(0.47-2.87). Modified starch, 3-7 wt.%, calculated on dry matter, is introduced as a temporary technological binder. Mass ratio of water and solid phase S:L=1:(1.5-2.5). The resulting suspension is processed in an ultrasonic device with an oscillation frequency of 22±1 kHz and an amplitude of 8±1 mcm for 10 minutes, then the suspension is filtered to a residual moisture content of 20-22 wt.%. Thermal activation is carried out at 500-700°C for 3-5 hours. Hydrothermal crystallization is carried out in one stage in a microwave oven at a specific microwave power of 1-2 kW/kg for 0.5-1.5 hours in a liquid glass solution with silicate modulus 1-3 and mass ratio S:L=1:(2-3).

EFFECT: increase in adsorption moisture capacity by an average of 5.6% and a dynamic capacity for water vapor by an average of 6.5%, as well as an increase in mechanical crushing strength by an average of 11.5% compared to the prototype.

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