Abstract:

Monolithic NaY zeolite was synthesized by dry gel conversion method.XRD,SEM and XRD were used to study the raw materials and products.The influences of n（SiO₂）/n（Al₂O₃）,n（Na₂O）/n（SiO₂）,water content,crystallization temperature and crystallization time on the preparation of monolithic NaY zeolite were systematically investigated.Experimental results showed that when n（SiO₂）/n（Al₂O₃） of synthesis system was 7.5,the n（SiO₂）/n（Al₂O₃） of framework was 6.12.The crystallinity of the NaY zeolite increased with the amount of n（Na₂O）/n（SiO₂） firstly.If n（Na₂O）/n（SiO₂） was above 0.35,the NaY zeolite would turn to P zeolite.When the crystallization temperature increased from 90 ℃ to 120 ℃,the crystallinity of product increased accordingly.After crystallization at 110 ℃ for 20 h,the crystallinity of product was 98% and stated stable.Water was the key factor in the process of dry gel conversion.When the n（H₂O）/n（SiO₂） reached about 4.2,it was good for the synthesis of NaY zeolite.

Key words: monolithic zeolite, dry gel conversion, NaY zeolite, kaolin