Recovery of zinc values from a solution containing hydrocyanic acid
CA 2090348 A1 · Owner: Ann Huber · Inventors: Kidby, Denis Keith; Menne, David Martin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to the recovery of zinc values from an acidic solution containing hydrocyanic acid. The zinc is recovered as complex zinc cyanide anions which may if, desired, be recycled for the (selective) preliminary removal or separation of adsorbed copper values from an (strong or weak base) anion exchange material, the anion exchange material additionally being loaded with adsorbed cyanide complexes of precious metal values such as gold and silver. The invention further relates to the recovery of cyanide values associated with copper cyanide complexes which are adsorbed on or taken up by an (strong or weak base) anion exchange material; the recovered cyanide values, for …
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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 February 25, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 25, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 25, 2015.
- 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.