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. 24, 2000
Filed:
Sep. 21, 1999
Applicant:
Inventors:
Josua Loffelholz, Langelsheim, DE;
Frank Behrens, Goslar, DE;
Assignee:
H. C. Starck GmbH & Co. KG, Goslar, DE;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
B22F / ;
U.S. Cl.
CPC ...
75369 ; 75622 ; 75228 ; 75368 ;
Abstract
The process comprises the reduction of niobium and/or tantalum oxides by means of alkaline earth metals and/or rare earth metals, wherein the first reduction stage is carried out as far as an average composition corresponding to (Nb, Ta)O.sub.x where x=0.5 to 1.5 and before the second stage the reduction product from the first stage is freed from alkaline earth oxides and/or rare earth metal oxides which are formed (and optionally from excess alkaline earth metal and/or rare earth metal) by washing with mineral acids.