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. 26, 1987
Filed:
Jul. 12, 1985
Ernest W Dewing, Kingston, CA;
Douglas N Reesor, Kingston, CA;
Alcan International Limited, Montreal, CA;
Abstract
A method of purifying aluminum contaminated with cerium or other rare earth metal comprises bringing the molten metal into contact with a halogenating agent. Preferred halogenating agents are aluminum fluoride for reducing cerium levels to around 0.1% to 0.3%, and chlorine gas for reducing cerium levels still further, and these may advantageously be used in sequence. Particulate aluminum fluoride may be introduced into the vortex of a stirred body of the molten metal. The controlled addition of chlorine may be effected by bubbling a mixture of chlorine and an inert gas into a body of the molten metal. The cerium contamination may arise from the use of a dimensionally stable anode comprising cerium dioxide in an aluminum reduction cell.