Manufacture of lead from sulphidic lead raw material
CA 1181244 A · Owner: Boliden Aktiebolag · Inventors: Jensfelt, Torsten E.; Petersson, Stig A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Lead is recovered from sulphidic lead raw-material containing impurities of the kind bismuth, arsenic, antimony and tin by flame-, -smelting the material with an oxygen-containing gas. The oxygen potential and temperature are adapted during the flame-smelting process so that the product formed thereby comprises substantially a lead-sulphide melt substantially free of volatile sulphidic and, metallic impurities of the said kind. The lead-sulphide melt is brought into contact with an oxidic lead material substantially free of impurities of the aforementioned kind while oxidising the, sulphide-sulphur content of the material and forming a melt substantially free of sulphur. Lead is recovered …
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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 January 22, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 22, 2002.
- 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.