Process of recovery of metals from aqueous ammoniacal solutions employing an ammonia antagonist having only hydrogen bond acceptor properties
US6210647A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1997 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | Nov 21, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An improved process for the extraction of a metal from an aqueous ammoniacal solution comprising: PA1 (i) contacting the aqueous ammoniacal solution with an extraction reagent comprised of a water insoluble extractant for the metal, to provide an organic phase, now containing metal values, and an aqueous phase from which metal values have been extracted; PA1 (ii) contacting the organic phase with an aqueous stripping solution to provide an aqueous strip phase, now containing metal values, and an organic phase from which metal values have been stripped; and PA1 (iii) recovering the metal values from the aqueous stripping solution; the improvement wherein (a) the extraction reagent contains an ammonia antagonist having only hydrogen bond acceptor properties; (b) the stripping solution is an aqueous highly acidic solution; and (c) the organic phase is washed with a weakly acidic aqueous solution prior to stripping with the highly acidic aqueous stripping solution. The extractant is preferably an oxime extractant, either a ketoxime or an aldoxime. The preferred hydrocarbon solvent is kerosene and the preferred antagonist is 2,2,4-trimethylpentane-1,3-diol diisobutyrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.