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:
Dec. 04, 1990
Filed:
Sep. 14, 1989
Applicant:
Inventors:
Assignee:
MTA Kozponti Fizikai Kutato Intezete, Budapest, HU;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
2041824 ; 204301 ;
Abstract
Acidification of impure alkali or ammonium tungstate or molybdate solutions prior to electrodialysis to produce tungstic acid or molybdic acid is carried out by the addition of pure tungstic acid or molybdic acid as the salts of tungsten isopolyacids or molybdenum isopolyacids, respectively. This is less expensive than using pure HCl or H.sub.2 SO.sub.4 and prevents contamination with chloride or sulfate ions. The pure tungstic acid or molybdic acid is isolated from the product.