Process for preparing crystalline zeolite composition ERC-2

Claim 1

A process for preparing a crystalline zeolite having a composition, in terms of mole ratios of oxides, in the range: 0.9 to 1.1 M.sub.2 O:Al.sub.2 O.sub.3 :2.5 to 5.1 SiO.sub.2 :0 to 6 H.sub.2 O where M is K or a mixture of K and Na, where Na is no more than 30 mole percent of the mixture, and characterized by having an X-ray powder diffraction pattern essentially identical to that given in Table IV which is characteristic of zeolite L, which comprises: (a) preparing a reaction mixture comprising water, a source of silica, metakaolin, KOH and up to about 30 mole percent of NaOH based on total moles of KOH and NaOH, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges: ______________________________________ M'.sub.2 O:Al.sub.2 O.sub.3 1.0 to 1.6 SiO.sub.2 :Al.sub.2 O.sub.3 2.5 to 5.1 H.sub.2 O:Al.sub.2 O.sub.3 80 to 140 ______________________________________ where M' is either K or a mixture of K and Na; and (b) maintaining the reaction mixture at between about 140° and 300° C. under autogeneous pressure for a sufficient period of time so as to form crystals of the zeolite.