The leaching of finely milled materials
CA 2017079 C · Owner: Metprotech Limited · Inventors: Evans, Dennis Edward; Liddell, Keith Stuart
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is provided in which fine milling of source material containing leachable values is carried out whilst the source material is in contact with the leach liquor and any necessary oxidants. The leach liquor and source material are preferably fed upwardly, as a slurry from the, bottom of the mill to the top. The mill has grinding media particles therein having a density of at least 1Kg/~ greater than that of the slurry passing through the mill and an impeller having radiating arms operating at an arm tip speed and power density selected to achieve the desired results. The process is especially useful for the milling and leaching of gold bearing materials such as pyrite, pyrrhotite and …
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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 May 17, 1990 and granted February 27, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 17, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 17, 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.