Method for processing trihydrate alumina bauxite with a low reactive silica content
CA 2190295 C · Owner: Lamerant, Jean-Michel · Inventors: Lamerant, Jean-Michel
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for processing trihydrate alumina bauxite with a low reactive silica content by subjecting said bauxite milled at atmospheric pressure to Bayer method alkaline etching is described being characterised in that a desilication or pre-desilication process is conducted prior to etching the milled bauxite for a period of at least 30 minutes at a temperature of not more than 108 ~C in the presence of a spent liquor aliquot with a non critical sol Al¿2?O¿3? g/l to caust Na¿2?O g/l concentration ratio (Rp) of 0.5 to 0.7 with a concentration of caustic soda of 140 to 170 g Na¿2?O/l to obtain a desilicated suspension with a dry matter concentration of at least 0.7 tons per m?3¿ of suspension …
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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 March 26, 1996 and granted September 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 26, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 26, 2018.
- 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.