Bioleaching sulfidic materials
CA 2305052 C · Owner: Sandstrom, Ake · Inventors: Lindstrom, Borje; Sundkvist, Jan-Eric; Sandstrom, Ake
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of leaching sulphidic material that contains metals and arsenic under oxidising conditions and with the aid of microorganisms is characterised by mixing the material with an acid aqueous solution to form a pulp and in that the material is leached in a first leaching stage at a pH of below 2 and . at a temperature that ranges from room temperature to about 55°C in the presence of an active quantity of microorganisms of the mesophilic and/or moderately thermophilic type wherewith the major part of the arsenic content of the material and possibly also part of its metal content is/are leached-out and the arsenic leached from said material is oxidised successively to a pentavalent …
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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 April 12, 2000 and granted July 8, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 12, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 12, 2022.
- 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.