Method for thiosulfate leaching of precious metal-containing materials
CA 2664756 C · Owner: Hackl, Ralph Peter · Inventors: Hackl, Ralph Peter; Fleming, Christopher Andrew; West-Sells, Paul George
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH reduction of polythionates, inert atmospheres to control polythionate production and electrolytic solutions which provide relatively high rates of precious metal recovery.
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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 18, 2001 and granted December 4, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 18, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 18, 2023.
- 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.