TRANSIENT CRYSTALLIZATION AND CRYSTAL SIZE DISTRIBUTION OF ZEOLITE-A

Transient crystallization and crystal size distribution of zeolite A have been correlated successfully by a set of modified population balance equations. The zeolite A crystal growth surface reaction, under hydrothermal synthesis conditions and without any hydrodynamic influence, was shown to be the controlling step. Experimental results from nucleation to the completion of crystallization as well as the corresponding crystal size distributions were presented and were used to compare the cases for surface reaction and mass transfer as the controlling mechanism. Consistently good agreement between prediction and experiments was achieved, especially between mean crystal size and predicted variance of crystal size distribution.