SYNTHESIS OF LARGE CRYSTAL ZEOLITES

摘要

PURPOSE: Large crystal zeolites are prepared by heating a zeolite synthesis mixture under agitation to a temperature equal to or less than the effective nucleation temperature of the zeolite synthesis mixture and thereafter the zeolite synthesis mixture is heated without agitation to a temperature equal to or greater than the effective nucleation temperature of the zeolite synthesis mixture. CONSTITUTION: A process for preparing large crystal zeolite comprising: (a) heating an aqueous synthesis mixture comprising sources of trivalent metal oxide, silica, alkali metal cations, optionally from 0 to 10 weight percent of seeds of zeolite, and optionally a directing agent under agitation to a temperature equal to or less than the effective nucleation temperature of said aqueous reaction mixture; and, (b) heating said aqueous synthesis mixture in the absence of agitation at a temperature equal to or greater than the effective nucleation temperature of said aqueous reaction mixture.