Ledge-free aluminium smelting cell
CA 2088482 C · Owner: Comalco Aluminium Limited · Inventors: Coad, Ian A.; Shaw, Raymond W.; Houston, Geoffrey J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aluminium smelting cell comprising side walls (5) and a floor (2) defining an active cathode, an anode (3) overlying the cathode floor (2), some said side walls (5) being covered by a wetted cathode material (6), such as one contained TiB2 so that the, covered side walls become active cathode surfaces on which a film of aluminium metal forms to protect the side wall parts against bath attack, thereby enabling the cell to operate at the desired temperatures without the usual protective side ledge of the frozen electrolyte material.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed August 19, 1991 and granted December 26, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 19, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.