Method for selective recovery of cadmium from cadmium-bearing waste
US4053553A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1976 |
| Grant date | Oct 11, 1977 |
| Priority date | — |
| Expiry date | Jan 14, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/84
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for the selective recovery of cadmium, nickel and cobalt from a nickel-cadmium battery waste which comprises: PA1 A. leaching the waste with an ammoniacal carbonate solution to form an aqueous ammoniacal carbonate solution containing cadmium, nickel and cobalt (II) ammine complexes and a leaching residue. Any iron in the waste is in the leaching residue. PA1 B. adding air to the aqueous ammoniacal carbonate solution to oxidize the cobalt (II) ammine complex to cobalt (III) ammine complex. PA1 C. contacting the resulting aqueous ammoniacal carbonate solution with a substantially water insoluble organic solution which contains a hydroxyoxime which forms a nickel compound readily soluble in the organic solution with any nickel present but which does not affect cadmium and cobalt (III). Nickel is thereby removed. PA1 D. precipitating the cadmium as a carbonate by removing ammonia from the aqueous ammoniacal carbonate solution and then removing the cadmium in the form of a carbonate. PA1 E. withdrawing a portion of the aqueous ammoniacal carbonate solution from the preceding step after precipitation of cadmium and precipitating the cobalt by removal of ammonia. PA1 F. returning…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.