Flotation process for purifying calcite
CA 2107730 A1 · Owner: Wang, Samuel S. · Inventors: Wang, Samuel S.; Hancock, Bill A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Alkoxylated alkyl amines and alkoxylated alkyl guanidines are excellent collectors when used in mineral froth flotation to remove quartz, micaceous minerals chlorite, pyrite and other mineral impurities from finely ground calcium carbonate to control tint color, and, abrasiveness.
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 October 5, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 5, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 5, 2015.
- 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.