Process for improved precious metals recovery from ores with the use of alkylhydroxamate collectors
CA 2075155 C · Owner: Nagaraj, Devarayasamudran R. · Inventors: Nagaraj, Devarayasamudran R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Collector compositions for use in froth flotation processes for the benefication of precious metals i.e. gold silver and platinum group metals (PGM) from sulfide ores containing especially pyrrite and pyrrhotite are disclosed. The collector comprises alkyl hydroxamic acids or their alkali metal or ammonium salts, preferably in combination with standard sulfide ore collectors such as xanthates etc.
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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 July 31, 1992 and granted May 14, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 31, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 31, 2014.
- 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.