| abstract |
A method for synthesizing molecular sieves is disclosed. The method comprises preparing an aqueous mixture comprising: a) a source zeolite, wherein said source zeolite contains sodalite substructures and has a tetrahedra atom density of less than about 15 TO2 per 1000 ANGSTROM 3, and wherein said source zeolite has a silica/alumina mole ratio greater than 200; an alkali metal oxide; and an organic template, and wherein said aqueous mixture has a composition in terms of mole ratios of oxides falling within the following ranges: -M+/SiO2 = 0.01-1.00 -OH-/SiO2 = 0.15-0.80 -H2O/SiO2 = 20-120 -Q/SiO2 = 0.10-1.00 -SiO2/Y2O3 > 200 - wherein M+ is an alkali metal not supplied by the source zeolite, Q is an organic template, Y is aluminum from the source zeolite, and Si is silica from the source zeolite; and (b) maintaining the aqueous mixture under conditions sufficient to form crystals of the molecular sieve. |