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:
Oct. 27, 1987
Filed:
Mar. 27, 1985
Daniel A Hoffner, Thann, FR;
Jean-Marie C Trautmann, Thann, FR;
Thann et Mulhouse, Thann-Haut-Rhin, FR;
Abstract
Pigmentary red iron oxide particulates essentially devoid of manganese impurities and ranging in shade from the orange-reds to the purplish reds, are conveniently prepared by (1) calcining, even at higher temperatures, an intimate admixture of (i) a ferrous sulfate hydrate containing contaminating amounts of manganese values, e.g., a by-product stream of ferrous sulfate, and (ii) an alkali metal compound, said admixture comprising from 0.08 to 1 gram-atom of alkali metal per mole of Fe.sub.2 O.sub.3 produced, (2) washing the calcined admixture with water to remove essentially all water-soluble manganese values therefrom, and advantageously (3) drying and (4) grinding the calcined and washed admixture.