Patent Yard Sign in
Expired Canadian patentCanada

Electrochemical processing of aqueous solutions

CA 2084183 C · Owner: Twardowski, Zbigniew · Inventors: Lipsztajn, Marek; Cowley, Gerald; Bechberger, Edward J.

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

The formation of sodium sulfate by-product in sulfuric acid-based chlorine dioxide generating processes is decreased and preferably eliminated entirely, by effecting electrochemical treatment of sodium ion-containing feed materials for the generator to remove sodium ions and to add hydrogen ions. Sodium hydroxide may be produced as a by-product. The process is generally applicable to the electrochemical treatment of alkali metal chlorates, alkali metal sulfates and mixtures thereof to produce acidified solutions useful in providing chlorate ion-containing feeds to such chlorine dioxide generating processes or for other purposes.

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 May 23, 1991 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 23, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 23, 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.
FiledMay 23, 1991
GrantedJuly 29, 2003
Term endedMay 23, 2011
Patent numberCA 2084183 C
Classification (IPC)C25B1/26 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedMay 23, 1991Patent grantedJuly 29, 2003Term endedMay 23, 2011

Sources & verification

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