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:
Sep. 21, 1982
Filed:
May. 15, 1981
Applicant:
Inventors:
John R Knoepke, Salt Lake County, UT (US);
David B George, Salt Lake County, UT (US);
Assignee:
Kennecott Corporation, Salt Lake City, UT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22B / ;
U.S. Cl.
CPC ...
75 63 ; 75 6 / ; 75 83 ; 75 9 / ; 75113 ;
Abstract
A method of pyrometallurgical refining of crude silver to remove base metal impurities, particularly bismuth, by treatment with sulfer hexafluoride gas. The crude silver is melted and maintained at about 1000.degree. C. while it is treated concurrently with sulfur hexafluoride and an oxidizing gas, such as air. Base metal fluorides are formed and are removed from the silver, after which the molten bath is treated with a reducing agent, such as hydrogen gas.