Method for selectively separating a non-ferrous metal
CA 2029623 C · Owner: Hoogovens Groep Bv · Inventors: Dijkhuis, Job; Van Sandwijk, Anthonie
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for selectively separating Zn from an acidic aqueous solution containing ions of Zn and Fe obtained by leaching of blast furnace dust using hydrochloric acid comprises first precipitating Fe from the solution and then treating the resultant Zn-containing solution with an alkali to precipitate Zn. The Zn-containing solution is treated in two stages; in the first precipitation step the pH is adjusted to from 4.0 to 4.3.
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 November 9, 1990 and granted April 30, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 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.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.