Method of producing crystalline ammonium metatungstate
CA 1238473 A · Owner: Gte Products Corporation · Inventors: Mcclintic, Robert P.; Kim, Tai K.; Macinnis, Martin B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating the ammonium paratungstate at from about 100°C to about 250°C for from about 1 hour to about 8 hours to remove some ammonia and water digesting, a solution of the heated ammonium paratungstate in water at from about 80°C to about 100°C for from about 2 hours to about 6 hours at relatively constant volume while maintaining the pH of the slurry at from about 4.2 to about 3.0 by addition of ammonia as necessary to form a solution of ammonium metatungstate in water. The ammonium metatungstate solution is then evaporated to concentrate it. Any insoluble material is …
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 June 28, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 28, 2005.
- 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.