Process for the production of aluminium hydroxide from bauxite
CA 2011860 C · Owner: Shell Internationale Research Maatschappij B.V. · Inventors: Rijkeboer, Albert; Den Hond, Roelof
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the production of aluminium hydroxide by digesting bauxite with alkali solution and precipitating aluminium hydroxide from the digestion solution, comprising:, a combining bauxite and alkali solution having a caustic concentration of at least 180 grams per litre expressed as sodium carbonate and digesting partly the bauxite in the combined product in a first digestion step at relatively low temperature, b separating reaction product obtained in step a into a liquid phase and a solids/liquid slurry c combining liquid phase and solids/liquid slurry obtained in step b and digesting the combined product in a second digestion step at relatively high temperature, d releasing heat from …
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 March 9, 1990 and granted February 22, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 9, 2012.
- 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.