Process for the recovery of noble metals and tertiary phosphines
CA 2086384 C · Owner: Plurichemie Anstalt · Inventors: De Carvalho, Alexandre Jose Ganchas; Heggie, William; De Oliveira Bandarra, Joao Jose
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention concerns a process for the recovery of a noble metal from an inorganic and/or organic residue in the form of a tellurium amalgam characterised by adding a solvent having a boiling point above 120°C to the, residue, removing by distillation water and other residual solvents having boiling points below the boiling point of the added solvent adding the, tellurium or reducible tellurium compound and then refluxing at, atmospheric pressure before separating the amalgam of the noble metal. The process of the present invention also allows the simultaneous recovery of the tertiary phosphine as its oxide from a residue containing a tertiary phosphine by the further stages of …
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 December 29, 1992 and granted September 7, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 29, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 29, 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.