METHOD FOR PRODUCING SYNTHETIC GRANULATED NAP ZEOLITE Russian patent published in 2018 - IPC C01B39/02 

FIELD: chemistry.

SUBSTANCE: invention relates to the preparation of a synthetic zeolite. Disclosed is a method of producing granular binder-free zeolite having a NaP, structure having an atomic ratio of Al:Si=1:(2÷3). Method includes mixing starting components, moulding granules, drying said granules, thermal activation and hydrothermal crystallisation in an alkaline solution. At the mixing step, metakaolin and liquid glass are added from with concentrations of SiO₂ 24.8÷34.3 wt%, silicate module 2.7÷2.9 and density of 1.36÷1.50 g/cm³, providing a mass ratio of metakaolin: liquid glass in the starting mixture 1:(24.41÷40.61). Obtained suspension is treated an ultrasonic device with a vibration frequency of 22±1 kHz and amplitude 8÷16 mcm for 20÷30 min, then the suspension is evaporated to a residual moisture of 28÷29 wt%. Thermal activation is carried out at 500÷700 °C for 2÷6 hours. Hydrothermal crystallisation is carried out in one step in an alkaline solution with concentration of sodium hydroxide 2÷4 mol/l at a temperature of 90÷110 °C and ratio of solid phase to NaOH solution of 1:(3÷5) for 1÷4 hours.

EFFECT: technical result is higher thermal stability of the zeolite at 80÷100 °C in comparison with the prototype.

1 cl, 1 dwg, 1 tbl, 6 ex