| Patent Number |
Title Of Patent |
Date Issued |
| 4612183 |
Method of producing crystalline ammonium metatungstate |
September 16, 1986 |
| A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating ammonium paratungstate in a multiple hearth furnace at from about 200.degree. C. to about 400.degree. C. to form a relatively uniformly heated ammonium para |
| 4612181 |
Method of producing crystalline ammonium metatungstate |
September 16, 1986 |
| A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating the ammonium paratungstate in a multiple hearth furnace at from about 200.degree. C. to about 400.degree. C. to form a relatively uniformly heated ammonium |
| 4560539 |
Removal of ammonia from sodium tungstate solutions |
December 24, 1985 |
| A process is disclosed for removing ammonia from a sodium tungstate solution. The process involves heating the solution at from about 80.degree. C. to about 95.degree. C., while at the same time maintaining the pH above about 9.4 by addition of sodium hydroxide to the sodium tungstat |
| 4360503 |
Recovery of tungsten values from alkali tungstate solutions by solvent extraction |
November 23, 1982 |
| In a two component extraction system for producing ammonium tungstate from aqueous alkali metal tungstate from aqueous alkali metal tungstate solution, the stripped organic is washed to form a wash solution which is mixed with concentrated ammonia solution to form an aqueous ammonia |
