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:
May. 07, 2002
Filed:
Aug. 31, 2000
Applicant:
Inventors:
Raj P. Singh, Sayre, PA (US);
Michael J. Miller, Towanda, PA (US);
Assignee:
Osram Sylvania Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G 3/500 ; C01B 9/08 ; C01C 1/00 ;
U.S. Cl.
CPC ...
C01G 3/500 ; C01B 9/08 ; C01C 1/00 ;
Abstract
A direct dissolution method for the purification of technical grade hydrated ammonium tantalum oxide (HATO), (NH ) H Ta O .nH O), and related compounds such as tantalum hydroxide and tantalum oxide is described. The method preferably uses ammonium bifluoride as fluoride source in place of the hydrofluoric acid used in the conventional methods. Other fluoride compounds such as NaF, KF, and CaF may be used.