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:
Aug. 03, 1993
Filed:
Dec. 17, 1991
Philip G Evans, Bathurst, CA;
Peter J Hancock, Montreal, CA;
Cameron L Harris, Montreal, CA;
Ralph L Harris, St. Lambert, CA;
Brunswick Mining and Smelting Corporation Limited, Bathurst, CA;
Abstract
A process of treating argentiferous alloy variously called 'zinc crust' or 'silver crust', obtained in the separation of silver from lead, removes sufficient zinc in one apparatus and process step to ensure the product is suitable as feed to cupellation. Suitable feed is defined as material, when partially oxidized in a cupel to remove impurities from silver, results in a litharge that is liquid at typical cupellation temperatures. The process requires that care be taken to avoid excessive oxidation of the crust during its formation. No preliminary step to upgrade the crust is necessary, avoiding the associated expense and effort.