Disposal of arsenic from sulfur dioxide-containing solutions
CA 2255874 C · Owner: Tenbergen, Reichel Abelis · Inventors: Krause, Eberhard; Okita, Yoshiaki; Raskauskas, Justin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The process provides a method of removing arsenic from solutions containing sulfur dioxide in an environmentally acceptable manner. This process first oxidizes arsenic iron and sulfur dioxide contained in an aqueous solution to prepare the solution for precipitation and to improve process control. Recycled neutralized precipitate seeds the oxidized aqueous solution. A calcium-containing base precipitates products of neutralization on the seeds. The final neutralized precipitate contains a stable ferric arsenate compounds.
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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 December 7, 1998 and granted May 27, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 7, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 7, 2020.
- 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.