Further improvements in tungsten recovery
CA 1281552 C · Owner: Anderson, Diana Mary · Inventors: Anderson, Diana Mary; Hutton, Denis Albert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Further Improvements in Tungsten Recovery The scarcity of high grade tungsten ores obliges users to seek to recover it from scrap materials but drill bits, in particular pose especial problems. Existing proposals to use acidic hydrogen peroxide to oxidise and solubilise tungsten is extremely inefficient in reagent consumption per unit tungsten recovered. According to the present invention hydrogen peroxide, can be used considerably more efficiently in the extraction of tungsten into an aqueous acidic solution by employing certain promoters which are solid at 50°C in the form of fused blocks. These blocks release the promoter slowly into the reaction solution and achieve similar efficiency …
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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
- Granted March 19, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 19, 2008.
- 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
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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.