Solvent extraction process
CA 2037377 C · Owner: Ici Americas Inc. · Inventors: Greenshields, James Nairn; Tetlow, Peter Eric
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A metal extraction process in which an aqueous leach solution containing metal values is contacted with a solution in a, water-immiscible organic solvent of an extracting agent where the, aqueous leach solution contains a wetting agent in a concentration of not more than 0.1% by weight. Wetting agents which may be used include alkoxylated alcohols or phenols especially alcohols, condensed with both ethylene oxide and propylene oxide and ethylene, oxide/propylene oxide/ethylene oxide block copolymers. The wetting agent can be present at a concentration of 0.00001% w/v or less. The presence of the wetting agent may reduce the build up of solid as crud and/or may reduce entrainment of one …
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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 February 28, 1991 and granted January 9, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 28, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 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.