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Expired Canadian patentCanada

Depression of the flotation of silica or siliceous gangue in mineral flotation

CA 2014882 C · Owner: Fee, Basil S. · Inventors: Fee, Basil S.; Leonard, Donald E.; Klimpel, Richard R.

CIPO record

Overview

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

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Abstract From the Canadian patent

A flotation process is disclosed wherein the selectivity to the valuable mineral is improved by the depression of silica or siliceous gangue by the use of a hydroxy-containing compound such as an alkanol amine. The process is useful in the flotation of oxide minerals as well as in sulfide flotation.

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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 April 19, 1990 and granted February 20, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 19, 1990
GrantedFebruary 20, 1996
Term endedApril 19, 2010
Patent numberCA 2014882 C
Classification (IPC)B03D1/01 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedApril 19, 1990Patent grantedFeb 20, 1996Term endedApril 19, 2010

Sources & verification

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