| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 423594130 | Tungsten containing (e.g., tungstate, etc.) | 7 |
| 20100028250 | METHOD FOR PRODUCTION OFAMMONIUM PARATUNGSTATE TETRAHYDRATE AND HIGHLY PURE AMMONIUM PARATUNGSTATE TETRAHYDRATE - The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner. | 02-04-2010 |
| 20100040532 | METHOD FOR MAKING AMMONIUM METATUNGSTATE - A method for producing ammonium metatungstate from ammonium paratungstate includes preparing an ammonium paratungstate mixture including solid ammonium paratungstate and water. The mixture is contacted with a cation exchange material to lower a pH of the mixture to a pH range wherein metatungstate ion is stable and an insoluble tungstic acid is not formed. The pH of the mixture may be maintained in the pH range until the ammonium paratungstate mixture is converted into an ammonium metatungstate solution. | 02-18-2010 |
| 20100098619 | METHOD FOR PRODUCING AMMONIUM PARATUNGSTATE HYDRATES AND AMMONIUM PARATUNGSTATE DECAHYDRATE - The invention is directed to a process for the continuous preparation of ammonium paratungstate hydrate by back reextraction of a tungsten-laden organic phase with an ammonia-containing aqueous solution in a mixer-settler apparatus. The reextraction is carried out at an NH | 04-22-2010 |
| 20110002840 | Method for Making Ammonium Metatungstate - A method for producing ammonium metatungstate from ammonium paratungstate includes preparing an ammonium paratungstate mixture including solid ammonium paratungstate and water. The mixture is contacted with a cation exchange material to lower a pH of the mixture to a pH range wherein metatungstate ion is stable and an insoluble tungstic acid is not formed. The pH of the mixture may be maintained in the pH range until the ammonium paratungstate mixture is converted into an ammonium metatungstate solution. | 01-06-2011 |
| 20110070148 | METHOD FOR PRODUCTION OF AMMONIUM PARATUNGSTATE TETRAHYDRATE AND HIGHLY PURE AMMONIUM PARATUNGSTATE TETRAHYDRATE - The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner. | 03-24-2011 |
| 20120141359 | PROCESS FOR PREPARING AMMONIUM METATUNGSTATE - A process for preparing ammonium metatungstate using ammonium paratungstate as raw material comprising: (A) leaching wet ammonium paratungstate with nitric acid to obtain a dilute solution of ammonium metatungstate; (B) concentrating the dilute solution of ammonium metatungstate to be a concentrated solution of ammonium metatungstate; and (C) spray-drying the concentrated solution of ammonium metatungstate to obtain powder of ammonium metatungstate. | 06-07-2012 |
| 20120328506 | METHOD FOR PRODUCING AMMONIUM TUNGSTATE AQUEOUS SOLUTION - A method for producing an ammonium tungstate aqueous solution includes the steps of: adding sulfuric acid to a solution containing tungstate ions; bringing the solution having the sulfuric acid added therein, into contact with an anion exchange resin; and bringing the anion exchange resin into contact with an aqueous solution containing ammonium ions. | 12-27-2012 |
