Recovery of aluminium and fluoride values from spent pot lining
CA 2097809 A1 · Owner: Jenkins, David Hughes · Inventors: Jenkins, David Hughes
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the recovery of aluminium and fluoride values from spent pot lining material comprises: (a) leaching the material in a solution containing a mineral acid and the corresponding aluminium salt in such proportions as to dissolve the aluminium and fluoride values, and (b), subjecting the leached liquid to thermal hydrolysis to cause precipitation of an aluminium fluoride product. Preferably, the spent pot lining material is calcined before leaching to produce an ash having environmentally acceptable levels of cyanide contamination. Preferably the leaching is carried, out in two stages: the acid and the spent pot lining material are mixed first and mixture is aged to prevent the …
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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 January 6, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 6, 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.