Process for making crystalline siliceous materials

A process to make a ZSM-5 zeolite

• (a) having a SiO.sub.2 to Al.sub.2 O.sub.3 mole ratio R between about 20 and 120,
• (b) having crystallites with their smallest dimension below about 0.3 micrometer, and
• (c) having a crystallinity of greater than 71% as measured by X-ray diffraction,
• (d) having an average unit cell represented by the formula ##STR17## where ##EQU4## M represents monovalent cations, x is the average number of Al atoms in the unit cell,
• .quadrature. represents the intersections of the channels inside the ZSM-5 porous framework free of tetrapropyl ammonium ions, and
• Q represents the intersections of the channels inside the ZSM-5 porous framework having occluded tetrapropyl ammonium ions, comprising
• reacting a mixture containing a source of silica, a source of alumina, a source of alkali metal hydroxide, water, and an organic template consisting essentially of tetrapropyl ammonium ions in the reaction mixture in an effective amount but less than that which corresponds to y=0.8 and in an amount such that the mole ratio of tetraproyl ammonium ions to SiO.sub.2 in said reaction mixture is 0.0087 or less, and recovering ZSM-5 zeolite product which is ion-exchangeable without requiring a preliminary calcination step.

A nonpolluting process to make a ZSM-5 zeolite

• (a) having a SiO.sub.2 to Al.sub.2 O.sub.3 mole ratio R greater than 5,
• (b) having crystallites with their smallest dimension below about 0.3 micrometer,
• (c) having a crystallinity of greater than 71% as measured by X-ray diffraction, and
• (d) having an average unit cell represented by the formula ##STR18## where ##EQU5## M represents monovalent cations, x is the average number of Al atoms in the unit cell,
• .quadrature. represents the intersections of the channels inside the ZSM-5 porous framework free of tetrapropyl ammonium ions, and
• Q represents the intersections of the channels inside the ZSM-5 porous framework having occluded tetrapropyl ammonium ions,
• comprising
• (i) reacting a mixture containing a source of silica, a source of alumina, a source of alkali metal hydroxide, water, and an organic template consisting essentially of tetrapropyl ammonium ions in the reaction mixture in an effective amount but less than that which corresponds to y=0.8 in the formula and in an amount such that the mole ratio of tetrapropyl ammonium ions to SiO.sub.2 in said reaction mixture is less than 0.01108, said mixture having an equivalent product concentration greater than 12%, at a rate corresponding to a throughput greater than 400 Kg/m.sup.3 /day, and
• (ii) recovering ZSM-5 zeolite product which is ion-exchangeable without requiring a preliminary calcination step and without prior removal of the occluded tetrapropyl ammonium ions.

A process to produce silicalite

• (a) having crystallites with their smallest dimension below about 0.3 micrometer, and
• (b) having an average unit cell represented by the formula ##STR19## where .quadrature. represents the intersections of the channels inside the ZSM-5 porous framework free of tetrapropyl ammonium ions, and
• Q represents the intersections of the channels inside the ZSM-5 porous framework having occluded tetrapropyl ammonium ions,
• comprising
• reacting a mixture containing a source of silica, a source of alkali metal hydroxide, essentially no alumina except as impurity, water, and an organic template consisting essentially of tetrapropyl ammonium ions in the reaction mixture in an effective amount but less than that which corresponds to y=0.8 and in an amount such that the mole ratio of tetrapropyl ammonium ions to SiO.sub.2 in the reaction slurry is 0.00792 or less, and recovering the silicalite product which is water washable without requiring a preliminary calcination step.