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. 11, 1977
Filed:
Jun. 22, 1976
Applicant:
Inventors:
Heinz Harnisch, Cologne-Lovenich, DT;
Klaus-Peter Ehlers, Erftstadt-Lechenich, DT;
Klaus Schrodter, Cologne, DT;
Assignee:
Hoechst Aktiengesellschaft, , DT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ; C01B / ; C01B / ;
U.S. Cl.
CPC ...
423313 ; 423309 ; 4233 / ;
Abstract
Alkali metal phosphate solutions of low vanadium content are produced from wet-processed phosphoric acids contaminated with vanadium and iron. The acids containing vanadium and iron in the highest stage of oxidation are treated with a reductant to effect conversion of the vanadium and iron contaminants to a lower stage of oxidation, the resulting acids are neutralized by means of an alkaline liquor and/or alkali metal carbonate down to a pH of at least 3, and the resulting precipitate is separated. The reductant used is the sodium salt of hydroxymethane-sulfinic acid.