Patent ID: 7459136

Claim:
A process for manufacturing a silicoaluminophosphate molecular sieve, said process comprising the steps of: (a) dissolving a silicon source into a solution containing a structure-directing template at conditions sufficient to establish a dissolved silicon concentration of at least 0.05 wt. %; (b) adding at least one aluminium source and at least one phosphorus source to at least a portion of the solution of step (a) to form a synthesis mixture, wherein at least the major portion of said aluminum source and phosphorus source are added to said solution after said solution has reached a dissolved silicon concentration of at least 0.03 wt. %; and (c) treating said synthesis mixture at a temperature sufficient to form said silicoaluminophosphate molecular sieve, wherein said silicoaluminophosphate molecular sieve comprises at least one intergrown phase of molecular sieves having AEI and CHA framework types, wherein said intergrown phase has an AEI/CHA mass ratio of from about 5/95 to 40/60 as determined by DIFFaX analysis.