METHOD OF PRODUCING SYNTHETIC GRANULAR TYPE A ZEOLITE Russian patent published in 2017 - IPC C01B39/28 

FIELD: chemistry.

SUBSTANCE: method is proposed for the preparation of a granular, without binding, zeolite with a PHI structure having an atomic ratio of Al:Si = 1:(2÷3). The method includes mixing the starting components, shaping the pellets, drying them, thermoactivation and hydrothermal crystallization in an alkaline solution. To the mixing step, alumina, solid sodium hydroxide, silica gel, sodium silicate pentahydrate and water are fed, providing a molar ratio of the components in the initial solid mixture Al₂O₃:Na₂SiO₃5H₂O:SiO₂:NaOH = 1:(0÷2):( 2÷6):(0÷4). The ratio of solid phase to water is 1:(5-15). The resulting slurry is processed in an ultrasonic device with a vibration frequency of 22±1 kHz and amplitude 8÷16 mcm for 5÷15 min, then the suspension is evaporated to a residual moisture of 25÷27 wt %. Thermal activation is carried out at 500÷700°C. Hydrothermal crystallisation is carried out in one step in an alkaline solution with a concentration of sodium hydroxide 2÷4 mol/l.

EFFECT: increasing the degree of crystallization, mechanical strength of the granules, and the dynamic equilibrium cation exchange capacity.

6 dwg, 3 tbl, 6 ex