Crystalline zeolite powder of type A (I)

US4303629A · kind A · utility

Assignee

• Degussa & Henkel Kommanditgesellschaft Auf Aktien · DE

Inventors

• Hans Strack · Alzenau, DE
• Wolfgang Roebke
• Dieter Kneitel · Rodenbach, DE
• Ehrfried Parr · Rodenbach, DE

Key dates

• Filing date: Oct 27, 1977
• Grant date: Dec 1, 1981
• Expiry date: Oct 27, 1997

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S423/24
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

There are produced crystalline zeolite powders of Type A with the composition 1.0.+-.0.2 M.sub.2/n O:Al.sub.2 O.sub.3 :1.85.+-.0.5 SiO.sub.2 .multidot.y H.sub.2 O where M is a metal cation, n is its valence and y has a value up to 6 with 50 weight % of the particles not over 4.0.mu. and with a particle spectrum ______________________________________ Fraction (.mu.) Portion (weight %) ______________________________________ <3 35 to 60 <5 82 to 95 <10 93 to 99 <15 96 to 100 ______________________________________ by hydrothermally crystallizing a SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O and water containing alkali aluminate, water, silicate synthesis mixture with optionally a tempering step wherein in a given case during the crystallization or tempering step instead of stirring shearing forces are employed. The process comprises providing an aqueous alkali silicate soluton, heating it to a temperature between 30.degree. and 80.degree. C., adding to the alkali silicate solution with stirring aqueous sodium aluminate having a content of 0.1 to 100 grams Al.sub.2 O.sub.3 /l and 1 to 200 grams Na.sub.2 O/l and which had been pre-warmed to from 30.degree. to 100.degree. C. until the turbidi…