TRANSIENT CRYSTALLIZATION AND CRYSTAL SIZE DISTRIBUTION OF ZEOLITE-A

Transient crystallization and crystal size distribution of zeolite A h ave been correlated successfully by a set of modified population balan ce equations. The zeolite A crystal growth surface reaction, under hyd rothermal synthesis conditions and without any hydrodynamic influence, was shown to be the controlling step. Experimental results from nucle ation to the completion of crystallization as well as the correspondin g crystal size distributions were presented and were used to compare t he cases for surface reaction and mass transfer as the controlling mec hanism. Consistently good agreement between prediction and experiments was achieved, especially between mean crystal size and predicted vari ance of crystal size distribution.