Process for preparing uniform MFI-type zeolite crystals
AssigneeExxon Chemical Patents Inc. (ECPI)
InventorJohannes Petrus Verduijn
Life of this patent
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Abstract
MFI zeolite crystals of uniform and controllable size may be produced by mixing: (i) a source of particulate silica in which silica particles present have an average diameter of 1 .mu.m or less; (ii) seeds of an MFI zeolite having an average diameter of 100 nm or less in the form of a colloidal suspension; (iii) an organic structure directing agent; and (iv) a source of fluorine or an alkali metal; to form an aqueous synthesis mixture, the seeds being present in an amount of 0.05 to 1700 ppm by weight of the synthesis mixture, and the synthesis mixture having an alkalinity in terms of OH.sup.- /SiO.sub.2 molar ratio of less than 0.1, and allowing the synthesis mixture to crystallize.
Claims13
A process for the preparation of an MFI-type zeolite comprising mixing:
- (i) a source of particulate silica in which silica particles present have an average diameter of 1 .mu.m or less;
- (ii) seeds of an MFI zeolite having an average diameter of 100 nm or less in the form of a colloidal suspension;
- (iii) an organic structure directing agent;
- and
- (iv) a source of fluorine or an alkali metal;
- to form an aqueous synthesis mixture, the seeds being present in an amount of 0.05 to 1700 ppm by weight of the synthesis mixture, and the synthesis mixture having an alkalinity, expressed as a molar ratio of OH.sup.- /SiO.sub.2, of less than 0.1, and allowing the synthesis mixture to crystallise.
Dependencies are inferred from the claim text.