Process for the production of very fine-particle zeolitic alkali metal aluminum silicates

A process for the production of very fine-particle zeolitic alkali metal aluminum silicates corresponding to formula (I):

• xMe.sub.2 O.Al.sub.2 O.sub.3.y SiO.sub.2.zH.sub.2 O (I)
• in which
• Me is sodium and/or potassium,
• x is a number of 0.8 to 1.3,
• y is a number of 1,3 to 10, and
• z is a number of 0 to 6,
• comprising the steps of
• A) mixing together two reaction components, wherein the two reaction components are an aqueous solution of at least one sodium or potassium alkali metal silicate and an aqueous solution of at least one sodium or potassium alkali metal aluminate, in the presence of more than the stoichiometrically necessary quantity of an aqueous solution of at least one alkali metal hydroxide selected from the group consisting of sodium hydroxide and potassium hydroxide, wherein the mixing is carried out with intensive stirring over a period of less than 10 minutes at a temperature in the range of from about 20.degree. to about 70.degree. C. to form an amorphous alkali metal aluminum silicate gel and wherein at least one of the two reaction components is present in less than the stoiciometrically necessary quantity, or both reaction components are present in the stoichiometrically necessary quantity:
• B) mixing the reaction mixture from step A) for from about 5 to about 40 minutes at a temperature in the range of from about 20.degree. to about 70.degree. C. to age the amorphous gel formed in step A);
• C) heating the reaction mixture while mixing for from about 5 to about 30 minutes at a temperature of more than about 70.degree. C. to the boiling point of the reaction mixture;
• and
• D) adding thereto from about 2 to about 50 mole % of at least one of the alkali metal aluminate and alkali metal silicate reaction components, based on the quantity of the reaction components used in step A), wherein the addition is in an amount sufficient to either make up the balance to the stoichiometrically necessary quantity thereof or as a stoichiometric excess, while maintaining the amorphous alkali metal aluminum silicate gel for at least about 10 minutes at a temperature in the range of more than about 70.degree. C. to the bolling point of the reaction mixture to crystallize said gel;
• wherein the term "stoichiometrically necessary quantity" is based on the stoichiometry of the zeolitic alkali metal aluminum silicate of formula I;
• and wherein the compounds of formula I include zeolites of the A type, zeolites of the P type, and zeolites of the faujasite type.