SALT EFFECTS ON THE SYNTHESIS OF SOME ALUMINOUS ZEOLITES

Highly aluminous (Al/Si approximate to 1) zeolite X and sodalite were synthesized in the presence of Cl-, Br-, and I-. The rate of synthesis increased strongly with halide concentration. At a fixed salt concent ration the rates were in a Cl-/Br-/l(-) ratio of 6:3:1. The sodalite p roduced contained cages almost saturated with salt. The sodalite cages in zeolite X were only partially filled. The kinetics of sodalite syn thesis could be simulated by a model in which nucleation occurred thro ughout the synthesist a rate that depended on halide concentration but not halide type.