Recovering chemical values from black liquor
CA 2185904 C · Owner: Matthew, Mani C. · Inventors: Matthew, Mani C.; Bonsu, Alexander K.; Thorman, Raymond P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for the recovery of chemical values from spent lignocellulosic pulping liquor salts to produce white liquor of different sulfidities. Preferably, the white liquor is in the form of separate liquid streams, each of which is of a sulfidity that is different from the sulfidity of others of the streams. The method also provides for developing a white liquor stream which is essentially free of sulfide values but, which contains sodium hydroxide. Further the method provides, for the recovery of titanium values for recycling.
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 April 18, 1995 and granted July 10, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 18, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 18, 2017.
- 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.