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Expired Canadian patentCanada

Method for capping mine waste and tailing deposits

CA 2273235 C · Owner: Glencore Canada Corporation · Inventors: Sudbury, Michael P.

CIPO record

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Abstract From the Canadian patent

A method for providing a composite capping cover for maintaining the surface of a sulphide bearing tailing and mine waste containing deposit moist thereby substantially eliminating oxidation of the sulphidic particulate in the deposit and the formation of heavy metal salts. The moisture is provided by atmospheric precipitation. The composite capping cover comprises a fine particulate layer, a fine-granular particulate layer and a coarse-granular particulate layer, the particle sizes of the particles making up the individual, the layers having been selected such that the hydraulic conductivity of the layers increases with successive layers while the matric suction value within the …

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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 May 27, 1998 and granted February 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2018.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 2020.
  • 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 27, 1998
GrantedFebruary 26, 2002
Term endedMay 27, 2018
Patent numberCA 2273235 C
Classification (IPC)B09B1/00

Timeline

Timeline From CIPO dates

1999200120032005200720092011201320152017Application filedMay 27, 1998Patent grantedFeb 26, 2002Term endedMay 27, 2018

Sources & verification

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