Process for preparation of an ECR-5 crystalline zeolite composition

A process for preparing a crystalline zeolite having a composition, in terms of mole ratios of oxides, in the range:

• 1.0 to 1.3 (Li, Na).sub.2 O Al.sub.2 O.sub.3 :2.0 to 5.0 SiO.sub.2
• and being isostructural with cancrinite, as shown by its characteristic x-ray diffraction pattern and having a sorption capacity greater than about 1% by weight hexane, comprising the steps of
• (a) preparing a reaction mixture in an aqueous solution including a source of silica-alumina, said reaction mixture having a composition;
• in terms of mole ratios of oxides, within the following ranges:
• xM.sub.2 O:Al.sub.2 O.sub.3 :ySiO.sub.2 :zH.sub.2 O
• where
• x=1.5 to 2.8
• y=2 to 4
• z=50 to 140
• M=(Li+Na) ##EQU2## (b) maintaining the reaction at a temperature between about 80.degree. C. and 200.degree. C. and times between 0.1 and 10 days.