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:
Feb. 25, 2003
Filed:
Sep. 22, 2000
Applicant:
Inventors:
Purnesh Seegopaul, Flemington, NJ (US);
Lin Gao, Piscataway, NJ (US);
Assignee:
N.V. Union Miniere S.A., Brussels, BE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22B 3/436 ;
U.S. Cl.
CPC ...
C22B 3/436 ;
Abstract
Tungsten carbide is formed from a tungsten material which is preferably tungsten carbide scrap. If scrap material is used, this is oxidized and acid leached to remove impurities and any binder material. This is then dissolved in a solution of sodium hydroxide and spray dried to form a precursor compound. A carbon compound such as citric acid can be added to the solution prior to spray drying to provide a carbon source for the tungsten carbide. The powder formed from the spray dried solution is calcined and carburized to form tungsten carbide.