Separation and recovery of metal values from natural bitumen ash
CA 2117155 C · Owner: Rigsby, Ledell · Inventors: Rigsby, Ledell; Woolery, Michael R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
High yields of vanadium containing virtually no nickel or magnesium are obtained from natural bitumen ash consisting of up to 5% carbon, more than 95% of water-soluble compounds of vanadium nickel and magnesium by mixing the ash with water to produce a 20% solids slurry of pH below 6.5 and temperature of 80-85° C oxidizing any reduced vanadium in the slurry and then separating and removing the resulting polyvanadate precipitate from the liquid phase containing substantially all the nickel and magnesium values of the ash.
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 7, 1994 and granted December 2, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 7, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 7, 2016.
- 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.