The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

Provided is a method for producing a MAZ-type zeolite, the method having an environmental impact which has been reduced as much as possible while not using a structure-directing agent as far as possible. In the method for producing a MAZ-type zeolite according to the present invention: (1) a silica source, an alumina source, an alkali source and water are mixed so as to form a reaction mixture that has a composition represented by a specific molar ratio; (2) a MAZ-type zeolite, which has a SiO.sub.2/Al.sub.2O.sub.3 ratio of 5-10, has an average particle diameter of at least 0.1 m and does not contain an organic compound, is added, as a seed crystal, into the reaction mixture in an amount of 0.1-30 weight % relative to the silica components in the reaction mixture; and (3) the reaction mixture, into which the seed crystal has been added, is heated at 80-200 C. in a closed system.

Provided is a method for producing a MAZ-type zeolite, the method having an environmental impact which has been reduced as much as possible while not using a structure-directing agent as far as possible. In the method for producing a MAZ-type zeolite according to the present invention: (1) a silica source, an alumina source, an alkali source and water are mixed so as to form a reaction mixture that has a composition represented by a specific molar ratio; (2) a MAZ-type zeolite, which has a SiO.sub.2/Al.sub.2O.sub.3 ratio of 5-10, has an average particle diameter of at least 0.1 m and does not contain an organic compound, is added, as a seed crystal, into the reaction mixture in an amount of 0.1-30 weight % relative to the silica components in the reaction mixture; and (3) the reaction mixture, into which the seed crystal has been added, is heated at 80-200 C. in a closed system.