Crystal growth modifier
CA 2045306 A1 · Owner: Nalco Australia Pty Limited · Inventors: Farquharson, Graeme J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to crystal growth modification and more particularly, to modification of crystal growth during precipitation of alumina in the Bayer process. Aluminous ores are digested in a caustic liquor to extract alumina values. The liquor is subsequently clarified to remove caustic insoluble materials and alumina crystals precipitated from the clarified liquor. In one aspect of the invention an, effective amount of a polysaccharide or a polysaccharide graft copolymer is added to the liquor after the clarification step and prior to or during the precipitation step. -- 1 --
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 June 24, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 24, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 24, 2013.
- 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.