Studies on the mechanism of synthesis of zeolite 4A from metakaolinite

XRD, FT-IR, ICP, SEM and chemical analysis have been used to examine the mechanism of: the synthesis of zeolite 4A from metakaolinite. When metakaolinite treated with NaOH solution, it is rapidly converted into metakaolinnite*. The processes of gelation of metakaolinite* and the crystallization of zeolite 4A from such gel are slow and simultaneous till the end of the crystallization. Liquid phase all takes an active part in the gelation of metakaolinite*, the formation of zeolite precursor and nucleation and the growth of zeolite 4A. The step that determines the rate of the zeolite crystallization process is the gelation of metakaolinite*. This crystallization process of zeolite 4A from metakaolinnite easily leads to form large numbers of polycrystals.