Preparation of zeolites

Claim 1

In a method for preparing a crystalline aluminosilicate zeolite from a reaction mixture containing sources of alkali metal cations, tetraalkylammonium cations, silica, alumina and water, said reaction mixture being maintained at a temperature of from about 75° C to about 205° C for from about 1 hour to about 60 days to crystallize said zeolite therefrom, the improvement wherein said zeolite is ZSM-4 or ZSM-5, characterized by a crystallinity of greater than 40 percent at the time of formation, prepared from a reaction mixture having the following compositional range in terms of mole ratios of oxides: ______________________________________ ZSM-4 ZSM-5 ______________________________________ Na.sub.2 O+R.sub.2 O/Al.sub.2 O.sub.3 0.60-1.75 0.15-0.85 Na.sub.2 O+R.sub.2 O/SiO.sub.2 0.24-0.65 0.04-0.18 Na.sub.2 O/Na.sub.2 O+R.sub.2 O 0.75-0.92 0.30-0.85 SiO.sub.2 /Al.sub.2 O.sub.3 1.8-4.3 1.8-6.0 H.sub.2 O/R.sub.2 O+Na.sub.2 O 9-60 35-360 ______________________________________ wherein R is a tetramethylammonium cation for ZSM-4 preparation and a tetraalkylammonium cation, the alkyl groups of which contain 2-5 carbon atoms, for ZSM-5 preparation, and wherein at least about 70 weight percent of the Al 2 O 3 is provided by an alumina-containing clay, said clay having been heated to a temperature of at least 1000° F, and further wherein the SiO 2 in the reaction mixture is provided such that the ratio of SiO 2 from a non-clay source/SiO 2 from said clay is from 0 to about 5.