Patent Yard Sign in
Expired Canadian patentCanada

Treatment of cyanide-ferrocyanide effluents

CA 1234931 A · Owner: Inco Limited · Inventors: Devuyst, Eric A.P.; Conard, Bruce R.; Tandi, Branka

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

A process for treatment of cyanide-containing aqueous effluents in which ferrocyanide present is precipitated with a metal other than copper, preferably zinc either prior to or simultaneously with the treatment of the effluent with sulfur dioxide and air in the presence of soluble copper.

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

  • Granted April 5, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 5, 2005.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 28, 1984
GrantedApril 5, 1988
Term endedApril 5, 2005
Patent numberCA 1234931 A
Classification (IPC)C02F1/58 +2 more

Timeline

Timeline From CIPO dates

1985198819911994199720002003Application filedMay 28, 1984Patent grantedApril 5, 1988Term endedApril 5, 2005

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.