Method of purifying tantalum
CA 1283523 C · Owner: Sumitomo Chemical Co. Ltd. · Inventors: Niwa, Kenji; Ichikawa, Ichiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for obtaining high-purity tantalum pentoxide is disclosed, which comprises the following steps:, dissolving a crude tantalum-containing compound in an acid containing hydrofluoric acid mixing and bringing the resulting acidic aqueous solution of the crude tantalum-containing compound into contact with an organic solution composed of a waterinsoluble quaternary ammonium compound and a waterinsoluble organic solvent, to extract the tantalum from said acidic aqueous solution into said organic solution; mixing said organic solution with an aqueous solution containing at least one compound selected from the group consisting of an inorganic acid and an ammonium salt, to remove any of the …
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
- Granted April 30, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 30, 2008.
- 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.