Method of preparing crystalline zeolitic aluminosilicates

DETAILED DESCRIPTION What is claimed is: 1.
In a method of preparing crystalline ZSM-5 or ZSM 11 zeolites with an atomic Si-to-Al ratio.
gtoreq.
10 by hydrothermal crystallization from a reaction batch that contains SiO.
sub.
2 and Al.
sub.
2 O.
sub.
3 or their hydrated derivatives or alkali silicates and aluminates along with crystallization accelerators, in an aqueous and alkaline medium, the improvement wherein an aged but still X-ray amorphous aluminosilicate nucleating gel with an atomic Si-to-Al ratio.
gtoreq.
20 which has been aged at 15.
degree.
to 100.
degree.
C.
from 2 to 100 days is added to the reaction batch as a crystallization accelerator.
2.
A method according to claim 1, wherein an aged nucleating gel with the composition (in molar terms) SiO.
sub.
2 :AlO.
sub.
2.
sup.
- .
gtoreq.
20, HO.
sup.
- :SiO.
sub.
2 =0.
05 to 1.
0, quaternary ammonium compound:SiO.
sub.
2 =0.
0 to 2.
0, H.
sub.
2 O:SiO.
sub.
2 =10 to 1000 is employed 3.
A method according to claim 1 wherein the aluminosilicate is prepared from a composition containing a quaternary ammonium compound which is a tetrapropylammonium salt.
4.
A method according to claim 1 wherein the aluminosilicate is prepared in the copresence of a quaternary ammonium compound, amine or a mixture of alcohol and ammonia.
5.
A method according to claim 4 wherein an amine, or a mixture of alcohol and ammonia is present in the reaction mixture.
6.
A method according to claim 1 wherein the nucleating gel is one that has been aged under atmospheric pressure.
7.
A method according to claim 6 wherein the nucleating gel is one that has been aged under atmospheric pressure at 20.
degree.
-60.
degree.
C.
by 10-50 days.
8.
A method according to claim 1 wherein the aged nucleating gel is added to reaction batches with the composition (in molar terms) SiO.
sub.
2 :Al.
sub.
2 O.
sub.
3 =5, HO.
sup.
- :SiO.
sub.
2 =10.
sup.
-10 -1.
0, quaternary ammonium compound:SiO.
sub.
2 =0.
01-2.
0, H.
sub.
2 O:SiO.
sub.
2 =0.
7-3000, and Me:SiO.
sub.
2 =0.
3-3.
0, where Me is an alkali or alkaline earth metal cation is added to said reaction batch