Recovery of tungsten values from tungsten- bearing materials
CA 1136422 A · Owner: Anglo American Corporation Of South Africa Limited · Inventors: Rees, Gwilym J.; Harris, Alfred M.; James, George S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of recovering tungsten values from a high grade tungsten bearing ore or concentrate such as scheelite or wolframite includes the steps of roasting, without fusion, the ore or concentrate in the presence of a reactive composition selected from the group of an alkali metal chloride, an alkali metal carbonate and mixtures thereof and extracting the water-soluble tungsten values from the roasted product, e.g. by water leaching. The reactive composition is preferably an alkali metal carbonate on its own.
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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 November 30, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 30, 1999.
- 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.