PROCESS FOR THE PREPARATION OF SMECTITES USING WATERGLASS

摘要

The present invention is directed to a process for the preparation of smectite type clays by hydrothermal treatment of a mixture containing a crystalline alumina, a divalent metal source, and waterglass. With the process according to the invention a method is provided for the direct preparation of smectite-type clays using inexpensive starting materials. Further with the process of the invention washing can often be avoided. It was further found that if waterglass is used with an additional type of silica source such as waterglass which has been ion exchanged and stabilized with ammonium ions, the surface area and sodium content of the resulting smectite-type clay can be influenced.