Ion flotatin with quaternary ammonium cationic surfactants
CA 2051097 A1 · Owner: Broken Hill Proprietary Company Limited (The) · Inventors: Nicol, Stuart K.; Engel, Malcolm D.; Smitham, James B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for ion flotation especially in the, extraction of gold uses as the flotation reagent a cationic surfactant of formula(I), wherein R1 is a C10-C18 alkyl group, R3is a lower alkyl group, or benzene ring optionally substituted with one or more lower alkyl groups and R2 and R4 are lower alkyl groups; or R1, R2 and R4 are methyl groups; R is a benzene ring substituted with a C10-C18 alkoxy group; and X is a halogen atom.
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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 April 3, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 3, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 3, 2012.
- 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.