Process for preparing a substantially crystalline sodium aluminosilicate

US4248847A · kind A · utility

Assignee

• Kali-Chemie Aktiengesellschaft · DE

Inventors

• Helmut Derleth · Nienburg, DE
• Ludwig Walter · Hannover, DE
• Karl-Heinrich Bretz · Nienburg, DE
• Artur Kurs · Nienburg, DE

Key dates

• Filing date: Feb 8, 1978
• Grant date: Feb 3, 1981
• Expiry date: Feb 8, 1998

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S423/24
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for preparing a synthetic substantially crystalline sodium aluminosilicate of the zeolite A type is disclosed. The process comprises rapidly and simultaneously introducing a sodium silicate and a sodium aluminate solution under thorough agitation at a constant by volume ratio which provides for a reaction mixture the content of which is equivalent to a molar ratio of x' Na.sub.2 O/ 1 Al.sub.2 O.sub.3 / y SiO.sub.2 /z' H.sub.2 O wherein x' is from about 6.5 to about 9.0, y is from about 1.7 to about 2.2 and z' is from about 180 to about 250, maintaining the reaction mixture at a temperature of from about 70.degree. to about 100.degree. C. under stirring for a sufficient period of time, usually 1-3 hours, in order to allow the initially amorphous reaction product to crystallize and recovering the substantially crystalline product from the resulting suspension. The essential feature of the process is a continuously maintained constant molar ratio Na.sub.2 O/ Al.sub.2 O/ SiO.sub.2 /H.sub.2 O throughout the reaction mixture during the entire course of the process. The resulting product exhibits a small particle size, an excellent wettability and a high calcium binding power, a…