Method for processing complex metal sulphide materials
CA 2102791 A1 · Owner: Petersson, Stig Arvid · Inventors: Sandstrom, Ake; Petersson, Stig Arvid
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for the treatment of complex metal sulphide materials and for the recovery of metal values from such materials. The process is characterized by first subjecting the material to a leaching process under conditions such that sulphide-sulphur is oxidized to sulphate and such that oxidized iron and impurities such as As will pass into solution whereafter, the leaching residue is melted for conventional pyrometallurgical recovery of the metal values. The invention also relates to the use of different embodiments of the process for recovering the precious metal values from refractory materials containing such values and for recovering metal from complex copper …
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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 June 17, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 17, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 17, 2014.
- 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.