Purification of copper sulfate solution
CA 1089188 A · Owner: Sherritt Inc. · Inventors: Weir, Donald R.; Vosahlo, Eva A.; Genik-Sas-Berezowsky, Roman M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for purifying copper sulfate solution by converting contained hexavalent selenium to tetravalent selenium which is amenable to removal from solution by heating and maintaining the solution at a temperature in the range of about 135 to 220°C under a non-oxidizing atmosphere in the presence of bivalent iron. The converted selenium is removed from the solution either by co-precipitation with ferrous iron oxidized and hydrolyzed to ferric oxide at a temperature in the range of 135 to 220°C and under an oxygen pressure of about 140 to 450 kPa or by cementation with a metal powder at a temperature in the range of about 25 to 85°C at about ambient pressure under a non-oxidizing …
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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
- Granted November 11, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 11, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.