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US 5,330,736 AGranted
Zeolite L synthesis and resulting product
AssigneeW. R. Grace & Co.-Conn.
InventorsJianxin Wu, David M. Chapman, Robert R. Gatte
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Abstract
Zeolite L is made from an aqueous precursor mixture that contains from 0.1 to about 10% by weight of an amorphous aluminosilicate seeding gel which does not contain zeolite L. Using this mixture zeolite L can be made in a much shorter time than with a synthesis mixture without the seeding gel, and with substantially no zeolite T impurity. When made at temperatures below about 120.degree. C the zeolite. L has a disk-shaped morphology which is substantially free of zeolite T (offretite type).
Claims8
A method for preparing a crystalline aluminosilicate zeolite L which comprises:
- (a) preparing an aqueous precursor mixture of silica, alumina, and alkali metal hydroxides within the range of the following molar compositions:
- Na.sub.2 O 0 to 8
- K.sub.2 O 2 to 9
- Al.sub.2 O.sub.3 1
- Si.sub.2 O 5 to 35
- H.sub.2 O 100 to 600
- (b) adding to said precursor mixture from about 0.1 to about 10 percent by weight of an amorphous aluminosilicate seeding gel which does not contain zeolite L and which has a molar composition of
- 15.+-.2 Na.sub.2 O
- 1 Al.sub.2 O.sub.3
- 14.+-.2 SiO.sub.2
- 350.+-.50 H.sub.2 O
- (c) stirring or homogenizing the mixture for from 2 minutes to over 2 hours to form a homogenous synthesis gel;
- and
- (d) reacting the synthesis gel at a temperature of from about 60 .degree. to 250.degree. C. for a period of time sufficient to produce crystalline zeolite L.
11 more elements
Dependencies are inferred from the claim text.