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. 28, 2003
Filed:
Mar. 30, 2002
Vittorio De Nora, Nassau, BS;
Jean-Jacques Duruz, Geneva, CH;
Moltech Invent S.A., Luxembourg, US;
Abstract
A method of inhibiting dissolution of a transition metal alloy anode ( ) of an aluminium electrowinning cell comprises providing a sodium-inert layer ( ′) on a sodium-active cathodic cell material ( ), such as carbon, and electrolysing alumina dissolved in a sodium ion-containing molten electrolyte ( ). Aluminium ions rather than sodium ions are cathodically reduced on the sodium-inert layer to inhibit the presence in the molten electrolyte ( ) of soluble cathodically-produced sodium metal that constitutes an agent for chemically reducing the anode's transition metal oxides and anodically evolved oxygen, thereby inhibiting reduction of the anode's transition metal oxides by sodium metal and maintaining the evolved oxygen at the anode at a concentration such as to produce at the alloy/oxide layer interface stable and coherent transition metal oxides having a high level of oxidation. The sodium-inert layer may comprise molten aluminium ( ) and/or a layer of refractory hard material ( ′).