Method for the control of sodium oxalate levels in sodium aluminate solutions
CA 2108785 C · Owner: Laurier, Jacques · Inventors: Laurier, Jacques; Sang, Jean Victor; Clegg, Robert Louis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is described for removing sodium oxalate from a sodium aluminate liquor produced through bauxite digestiol using the Bayer process. The novel sodium oxalate removal procedure comprises the steps of (a) continuously generating new and reactive seed particles of sodium oxalate by mixing together an aqueous solution of sodium oxalate and a portion of said Baye proccss sodium aluminate liquor to achieve a concentration of sodium oxalate within a range to generate spheroidal particles o sodium oxalate (b) adding a suspension of said spheroidal panicles of sodium oxalate as seed to a second portion of said Baye proccss sodium aluminate liquor, to thereby precipitate the remainder of …
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 1, 1992 and granted June 16, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 1, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 1, 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.