The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 18, 1993
Filed:
Apr. 26, 1991
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
For the preparation of crystalline sodium silicates having a sheet structure and an SiO.sub.2 /Na.sub.2 O molar ratio of 1.9:1 to 3.5:1 from waterglass solutions having a solids content of 20 to 65% by weight, the waterglass solutions are first treated in a spray-drying zone. This gives a pulverulent amorphous sodium silicate having a maximum ignition loss of 20% by weight, while the waste gas leaving the spray-drying zone is at a temperature of at least 140.degree. C. Thereafter, the spray-dried sodium silicate is heated in an ignition zone containing an agitated solid bed at temperatures of 500.degree. to 800.degree. C. for 1 to 60 minutes in the presence of at least 10% by weight of recycled material. This recycled material was obtained by mechanical comminution of crystalline sodium silicate discharged from the ignition zone.