Process for leaching gold and silver
CA 2067841 A1 · Owner: Ziegler, Annette · Inventors: Ziegler, Annette; Lorosch, Jurgen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In the so-called cyanidation-in-mill technique the, ores, ore concentrates and waste material from previous incomplete leachings which are to be leached are treated in the mill with a cyanide-containing leaching solution gold, and silver being at least partly leached. Compared with the known cyanidation-in-mill technique in the presence of hydrogen peroxide, the gold yield can be considerably increased if leaching is carried out in the presence of a peroxoborate compound. The peroxoborate may be present in solid and/or dissolved form. 10 to 60 equivalents peroxoborate are preferably used per t of the material to be leached.
Read the whole patent
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 May 1, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 1, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 1, 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.