Process for recovering tungsten from organic solutions
US4882131A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1987 |
| Grant date | Nov 21, 1989 |
| Priority date | — |
| Expiry date | Apr 30, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A tungsten extraction process wherein tungsten values are extracted from an aqueous alkali metal tungstate solution by an organic solution containing an amine extractant wherein the organic solution consists essentially of from about 6% to about 10% by volume of said amine extractant, and the balance of said organic solution being an aromatic solvent consisting essentially of a mixture of alkyl benzenes wherein the alkyl benzenes have molecular weights of 120, 134, or 148 and the total number of carbon atoms in the alkyl chains attached to the benzene ring are either 3, 4, or 5, and thereafter the tungstate values are removed from the organic solution by stripping with aqueous ammonia, is improved by carrying out the stripping step in the aqueous continuous mode, and having as the stripping agent, an aqueous solution of ammonium metatungstate having a tungsten concentration which allows the strip solution to have a specific gravity of no greater than about 1.5, the stripping agent having sufficient ammonia to maintain the pH of the stripping agent at from about 5 to about 8, with the temperature of the stripping agent being no greater than room temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.