METHOD OF PREPARING HIGH-SUILICON ZEOLITE Russian patent published in 1995 - IPC

FIELD: chemical technology. SUBSTANCE: reagent containing silicon (silica gel, silica sol, aluminosilicate, water glass) is mixed in capacity with stirrer with aluminium-containing reagents (sodium aluminate, aluminium hydroxide, aluminium salts of mineral acids), sodium hydroxide, alkaline metal salt solution and water up to formation of hydrogel or suspension of the following composition, mole: (3-10) Na₂O·Al₂O₃(20-100)·SiO₂·(3-25)Mn+2/

_nO(500-1500)H₂O, where M - alkaline metal in mineral salt composition. Prepared reaction mass is homogenized, placed into autoclave and crystallized at 120-200 C for 12-150 h. After termination of the main crystallization stage suspension is cooled up to 50 C with uniform temperature decrease at the rate 5-10 C per 1 h. Then zeolite is filtered off, washed and dried. Properties of prepared zeolite type ZSM-5: crystallinity degree is 105-115% and adsorptive capacity by heptane is 0,20-0,23 cm³/g. EFFECT: increased crystallinity and adsorptive capacity of product. 2 cl, 1 tbl