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:
Jan. 16, 1979
Filed:
Feb. 23, 1977
Klaus-Peter Ehlers, Erftstadt-Lechenich, DE;
Gero Heymer, Erftstadt-Liblar, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Alkali metal phosphate solutions (alkali metal oxide : P.sub.2 O.sub.5 - molar ratio greater than 1.9 : 1) of reduced vanadium and chromium contents are made from wet-processed phosphoric acids which are neutralized by means of an alkali metal hydroxide and/or carbonate. The alkali metal phosphate solutions contain less than 20 ppm of vanadium and less than 1 ppm of chromium and are made by stepwise neutralization. More specifically the acid is neutralized in a first step to an alkali metal oxide to P.sub.2 O.sub.5 - molar ratio of 1.0 : 1 to 1.8 : 1; resulting precipitate is separated and resulting solution is admixed with iron(II)salt at 60 to 90.degree. C. Next, the acid is neutralized in a second step to an alkali metal oxide to P.sub.2 O.sub.5 - molar ratio greater than 1.9 : 1, and resulting precipitate is separated again.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile