Cyanide recycling process
CA 2127437 C · Owner: Coeur Gold New Zealand Limited · Inventors: Mudder, Terry I.; Goldstone, Adrian James
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for recycling hydrogen cyanide from a cyanide-containing slurry (24) is provided. The process includes the steps of adjusting the pH (28) of a cyanide-containing slurry volatilizing HCN (30) , contained in the pH adjusted slurry (24) and contacting the volatilized HCN (44) with a precious metals-containing slurry (18) to recover precious metals (19) therefrom. Alternatively, the HCN can be contacted with reclaim or decant, water to recover , cyanide, thereby conserving resources.
Read the whole patent
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 January 4, 1993 and granted May 13, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 4, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 4, 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.