US4208380A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the recovery of cobalt from its impure, aqueous, in particular nickel-bearing, solutions and catalyst therefor
Assignee: Outokumpu Oyj
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Filing: 1978-07-07
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Granted: 1980-06-17
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Expires: 1998-07-07
Abstract
Abstract Cobalt is recovered as a finely-divided and anhydrous salt from impure, nickel-bearing, aqueous solutions of cobalt, by exposing the aqueous solution to oxidation at an elevated temperature in the presence of ammonia and the respective ammonium salt, the formation of cobalt (III) hexammine ions is catalysed with activated carbon or solid sulfides, a cobalt (III) hexammine salt is crystallized from the solution, the salt is separated from the solution and pyrolysed to form a cobalt (II) salt, and the released ammonia is returned to the oxidation stage.
Inventors
- 👤 Matti J. Hamalainen
- 👤 Jussi K. Rastas
- 👤 Heikki A. Tiitinen
- 👤 Tom O. Niemi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:14
CPC Classifications
C; C22; C22B; C22B23/00; C22B23/04; C22B23/0476; C22B23/0492
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
89 words
A process for the recovery of cobalt as a finely-divided and anhydrous salt from impure aqueous solutions of cobalt, comprising subjecting the aqueous solution to oxidation at an elevated temperature in the presence of ammonia, an ammonium salt, and a metal sulfide catalyst promoting the formation of cobalt(III) hexammine ions to form cobalt(III) hexammine salt, crystallizing a cobalt(III) hexammine salt out of the solution, separating the salt from the solution, pyrolysing the separated salt to form a cobalt(II) salt and ammonia, and recycling the released ammonia to the process.
Claim 2
Dependent Claim
89 words
A process for the recovery of cobalt as a finely-divided and anhydrous salt from impure aqueous solutions of cobalt, comprising subjecting the aqueous solution to oxidation at an elevated temperature in the presence of ammonia, an ammonium salt, and a metal sulfide catalyst promoting the formation of cobalt(III) hexammine ions to form cobalt(III) hexammine salt, crystallizing a cobalt(III) hexammine salt out of the solution, separating the salt from the solution, pyrolysing the separated salt to form a cobalt(II) salt and ammonia, and recycling the released ammonia to the process.
Claim 3
Dependent Claim
29 words
The process of claim 1, in which 4.5-6.5 moles of ammonia and 0.5-1.5 moles of ammonium sulfate per each cobalt and nickel mole are added to the aqueous solution.
Claim 4
Dependent Claim
29 words
The process of claim 1 in which the elevated temperature and the partial pressure at which the solution is subjected to oxidation are, respectively, 25°-90° C. and 0.2-5 bar.
Claim 5
Dependent Claim
22 words
The process of claim 1, in which the catalysis on the oxidized solution is performed at 25°-90° C., and at normal pressure.
Claim 6
Dependent Claim
18 words
The process of claim 1, in which the oxidation and the catalysis are performed during the same stage.
Claim 7
Dependent Claim
25 words
The process of claim 1, in which the crystallization of the cobalt(III) hexammine salt is performed by cooling the solution to below about 15° C.
Claim 8
Dependent Claim
25 words
The process of claim 5, in which ammonia is added to the crystallization stage in order to lower the solubility of the cobalt(III) hexammine salt.
Claim 9
Dependent Claim
32 words
The process of claim 1, in which the cobalt(III) hexammine salt is pyrolysed within the temperature range 250°-400° C. in order to produce CO 2 (NH 4 ) 2 SO 4 .
Claim 10
Dependent Claim
30 words
The process of claim 1, in which the cobalt(III) hexammmine salt is pyrolysed at a temperature of from 400° C. to 750° C. in order to produce CoSO 4 .
Claim 11
Dependent Claim
29 words
The process of claim 1, in which the cobalt(III) hexammine salt is pyrolysed at a temperature of from 750° C. to 1200° C. in order to produce cobalt oxide.
Claim 12
Dependent Claim
20 words
The process of claim 1, in which the aqueous solution is caused to flow through a bed of the catalyst.
Claim 13
Dependent Claim
33 words
The process of claim 11, in which the catalyst is mixed with an auxiliary substance, such as diatomite, in order to improve the ability of the catalyst to allow a flow through it.
Claim 14
Dependent Claim
16 words
The process of claim 1, in which the released ammonia is recycled to the oxidation stage.
Claim 15
Dependent Claim
29 words
A process according to claim 1 comprising adding to the impure aqueous cobalt solution a sulfide compound more easily soluble in the aqueous solution than cobalt and nickel sulfide.
Claim 16
Dependent Claim
42 words
The process of claim 1, in which ammonium sulfide or hydrogen sulfide or both are added to the aqueous solution before the use of the sulfide as a catalyst or at the time the sulfide is to be used as a catalyst.
Claim 17
Dependent Claim
23 words
The process of claim 1, in which the metal sulfide is cobalt or nickel sulfide or a sulfide of both nickel and cobalt.
Claim 18
Dependent Claim
14 words
The process of claim 4, in which the catalysis is performed at 50°-75° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-17 | 1983-12-17 | 1984-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-17 | 1987-12-17 | 1988-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-17 | 1991-12-17 | 1992-06-17 | $7700.00 | Window Closed / Lapsed |