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:
Nov. 10, 1981
Filed:
Feb. 28, 1980
C Norman Cochran, Oakmont, PA (US);
Nancy M Fitzgerald, Pittsburgh, PA (US);
Aluminum Company of America, Pittsburgh, PA (US);
Abstract
A method for production of aluminum by carbothermic reduction of Al.sub.2 O.sub.3 in a stack-type reactor. A charge of Al.sub.2 O.sub.3 and C is inserted into an upper reaction zone of the reactor and reacted at an elevated temperature to form CO and a first liquid comprising Al.sub.2 O.sub.3 and Al.sub.4 C.sub.3. The first liquid is transferred to a lower reaction zone beneath the upper reaction zone and heated to form CO and a second liquid of Al and C. A portion of the second liquid is removed, and liquid Al is extracted therefrom. In a preferred method, Al.sub.2 O.sub.3 and C in the upper zone are heated by partial combustion of the C, and the lower zone is heated electrically. Gaseous Al and Al.sub.2 O formed in the lower zone are reclaimed in the upper zone. Gaseous CO produced in both zones heats the Al.sub.2 O.sub.3 and C in the upper zone. Excess CO is removed from the upper zone and used for generation of electricity or chemical process use. Liquid Al.sub.4 C.sub.3 separated from the second liquid is returned to the upper zone. Production of 1.00 kg Al requires an expenditure of 32.7 megajoules (MJ) of electrical energy, and 3.45 kg C. Total consumption of electrical energy and carbon energy equivalent is 121 MJ/kg Al, compared with 186 MJ/kg Al using the best Bayer-Hall technology.