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Expired Canadian patentCanada

Waste treatment process for alkaline waste liquid

CA 2040538 C · Owner: Mitsubishi Nuclear Fuel Company, Ltd. · Inventors: Kamei, Yoshinobu; Shirato, Wataru

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

There is disclosed a waste treatment process for alkaline waste liquid in which substances to be removed exist in ionic and colloidal states. In the process, powdered tannin is added to the waste liquid to produce solid substance of the tannin and to capture the substances to be removed on the solid substance. Then the waste liquid is subjected to filtration to thereby separate the solid substance including the substances to be removed.

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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 16, 1991 and granted June 18, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 16, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 16, 2013.
  • 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 16, 1991
GrantedJune 18, 1996
Term endedApril 16, 2011
Patent numberCA 2040538 C
Classification (IPC)C02F1/54 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedApril 16, 1991Patent grantedJune 18, 1996Term endedApril 16, 2011

Sources & verification

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