Production of purified iron chloride by a vacuum process in the manufacture of titanium dioxide
CA 2078516 C · Owner: Kronos International, Inc. · Inventors: Schmeir, Erwin; Hartmann, Achim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the recovery of ferrous chloride contained in a suspension resulting from the chlorination of titaniferous raw material in the manufacture of titanium dioxide, comprises:, a) slurrying the suspension in fluid; b) removing the water-insoluble constituents from the slurry leaving a filtered solution;, c) evaporating the filtered solution under vacuum but only to an extent that chlorides do not crystallize; and, d) cooling the filtered solution, at least initially under vacuum, thereby crystallizing ferrous chloride. - 9 -
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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 September 17, 1992 and granted October 6, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 17, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 17, 2014.
- 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.