Gold recovery from refractory carbonaceous ores by pressure oxidation, thiosulfate leaching and resin-in-leach adsorption
CA 2209559 C · Owner: Barrick Gold Corporation · Inventors: Dreisinger, David; Thomas, Kenneth G.; Marchbank, Andrew R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for treatment of precious metal ores in which gold is leached from an oxidized ore slurry using a thiosulfate salt lixiviant and copper catalyst. Gold and copper are subsequently loaded onto an ion exchange resin. Copper is recovered from the resin by elution with a thiosulfate solution; gold is recovered from the resin by elution with a thiocyanate colution. Gold is recovered from the eluate by precipitation electrowinning, or cementation.
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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 July 3, 1997 and granted December 18, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 3, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 3, 2019.
- 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.