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:
Nov. 25, 1980
Filed:
Dec. 11, 1978
Wolfgang Rambold, Krefeld, DE;
Heinrich Heine, Krefeld, DE;
Bruno Raederscheidt, Krefeld, DE;
Gerhard Trenczek, Krefeld, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process for the production of low sulphur chromium(III) oxide comprising annealing at a calcining temperature from about 800.degree. C. to 1100.degree. C. a mixture of alkali metal chromate and about 0.7 to 0.96 times its molar amount of ammonium sulfate, and separating the chromium(III) oxide formed from the alkali metal salt. Advantageously the ammonium sulfate in the form of a concentrated solution is mixed with solid alkali metal dichromate and the mixture thereafter is adjusted prior to calcination to a water concentration of less than about 15% by weight of water.