Re-processing incinerator ash
CA 2010883 C · Owner: Sheridan, John Patrick · Inventors: Sheridan, John Patrick
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides methods for re-processing incinerator ash to recover phosphates and minerals therefrom. The incinerator ash may be agitated in a bath of sulphuric acid - which may be diluted or concentrated. The process may be carried out at elevated temperatures and/or pressures. Because the incinerator ash contains high concentrations of phosphates of calcium magnesium, aluminum, or any, of them, the agitated mixture will have phosphate-containing compounds which may then be separated from it. Thereafter optionally the residue, following the separation of the phosphate-containing compounds may be purged of any trace metallic elements that are present in it; and further …
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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 February 26, 1990 and granted August 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 26, 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.