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:
Apr. 15, 1986
Filed:
Aug. 06, 1984
Applicant:
Inventors:
Hans J Heinrich, Stein, DE;
Meinhard Aits, Burgfarrnbach, DE;
Assignee:
GFE Gesellschaft fur Elektrometallurgie mbH, Dusseldorf, DE;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
B22F / ;
U.S. Cl.
CPC ...
75 / ; 75 / ; 75121 ; 75251 ; 7510 / ;
Abstract
In the production of a vanadium group valve metal powder, especially tantalum, the reaction mixture of a double fluoride salt of the valve metal and metallic sodium and/or potassium is doped with sulfur before a melt cake is formed. The melt cake is then leached with water to eliminate central salts leaving the valve metal powder. The sulfur doping provides improved surface area and particle size characteristics.