US4175014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathodic dissolution of cobaltic hydroxide
Assignee: Cyprus Amax Minerals Co
•
Filing: 1978-03-06
•
Granted: 1979-11-20
•
Expires: 1998-03-06
Abstract
Abstract A method is provided for the recovery of cobalt from nickel solutions, wherein cobalt is separated from said solution as a precipitate containing cobaltic hydroxide precipitate and also containing nickel, the method comprising dissolving the precipitate for the subsequent recovery of cobalt therefrom by reducing trivalent metal in said precipitate to the divalent state. This is achieved by forming an aqueous slurry of said precipitate acidified with sulfuric acid to a pH ranging from about 0.1 to 2, subjecting the precipitate of said aqueous slurry to electrolytic reduction at the cathode of an electrolytic cell having an insoluble anode, said precipitate being isolated from said anode during said electrolytic reduction and continuing the electrolytic reduction of said precipitate from the trivalent to the divalent state and effect the dissolution thereof.
Inventors
- 👤 Ranko Crnojevich
- 👤 Edward I. Wiewiorowski
- 👤 Peter H. Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:43
CPC Classifications
C; C25; C25B; C25B1/00; C22; C22B; C22B23/00; C22B23/04; C22B23/0453; C22B23/0461; C25B1/01
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
In the recovery of cobalt from cobalt-containing nickel solutions, wherein cobalt is separated from said solution as a precipitate containing cobaltic hydroxide, the improved method of dissolving said precipitate for the subsequent recovery of cobalt therefrom by reduction of trivalent metal in said precipitate to the divalent state which comprises, forming an aqueous slurry of said precipitate acidified with sulfuric acid to a pH ranging from about 0.1 to 2, subjecting the precipitate of said aqueous slurry to electrolytic reduction at the cathode of an electrolytic cell having an insoluble anode, said precipitate being isolated from said anode during said electrolytic reduction, and continuing the electrolytic reduction of said precipitate at said cathode until reduction of trivalent metal in said precipitate to the divalent state obtains and hence the dissolution thereof.
Claim 2
Dependent Claim
131 words
In the recovery of cobalt from cobalt-containing nickel solutions, wherein cobalt is separated from said solution as a precipitate containing cobaltic hydroxide, the improved method of dissolving said precipitate for the subsequent recovery of cobalt therefrom by reduction of trivalent metal in said precipitate to the divalent state which comprises, forming an aqueous slurry of said precipitate acidified with sulfuric acid to a pH ranging from about 0.1 to 2, subjecting the precipitate of said aqueous slurry to electrolytic reduction at the cathode of an electrolytic cell having an insoluble anode, said precipitate being isolated from said anode during said electrolytic reduction, and continuing the electrolytic reduction of said precipitate at said cathode until reduction of trivalent metal in said precipitate to the divalent state obtains and hence the dissolution thereof.
Claim 3
Dependent Claim
48 words
The method of claim 1, wherein the electrolytic reduction is carried out at a cell voltage of 1.5 to 4 volts at a cathode current density of about 5 to 100 amps/sq.ft., and at a temperature ranging from ambient to below the boiling point of the aqueous slurry.
Claim 4
Dependent Claim
39 words
The method of claim 2, wherein the cell voltage ranges from about 2.5 to 3.5 volts, at a cathode current density of about 5 to 20 amps/sq.ft. and at a temperature ranging from about 50° C. to 80° C.
Claim 5
Dependent Claim
28 words
The method of claim 1, wherein as the pH rises during dissolution, sulfuric acid is added to control the pH over the range of about 0.8 to 1.2.
Claim 6
Dependent Claim
173 words
In the recovery of cobalt from cobalt-containing nickel solutions, wherein cobalt is separated from said solution as a precipitate containing cobaltic hydroxide and also containing nickel, the improved method of dissolving said precipitate for the subsequent recovery of cobalt therefrom by reduction of trivalent metal in said precipitate to the divalent state which comprises, forming an aqueous slurry of said precipitate acidified with sulfuric acid to a pH ranging from about 0.2 to 2, subjecting the precipitate of said slurry to electrolytic reduction at the cathode of an electrolytic cell having an insoluble anode at a cell voltage ranging from about 1.5 to 4 volts, at a cathode current density ranging from about 5 to 100 amps/sq.ft. and at a temperature ranging from ambient to below the boiling point of the aqueous slurry, said precipitate being isolated from said anode during said electrolytic reduction, and continuing the electrolytic reduction of said precipitate at said cathode until reduction of trivalent metal in said precipitate to the divalent state obtains and hence the dissolution thereof.
Claim 7
Dependent Claim
173 words
In the recovery of cobalt from cobalt-containing nickel solutions, wherein cobalt is separated from said solution as a precipitate containing cobaltic hydroxide and also containing nickel, the improved method of dissolving said precipitate for the subsequent recovery of cobalt therefrom by reduction of trivalent metal in said precipitate to the divalent state which comprises, forming an aqueous slurry of said precipitate acidified with sulfuric acid to a pH ranging from about 0.2 to 2, subjecting the precipitate of said slurry to electrolytic reduction at the cathode of an electrolytic cell having an insoluble anode at a cell voltage ranging from about 1.5 to 4 volts, at a cathode current density ranging from about 5 to 100 amps/sq.ft. and at a temperature ranging from ambient to below the boiling point of the aqueous slurry, said precipitate being isolated from said anode during said electrolytic reduction, and continuing the electrolytic reduction of said precipitate at said cathode until reduction of trivalent metal in said precipitate to the divalent state obtains and hence the dissolution thereof.
Claim 8
Dependent Claim
39 words
The method of claim 5, wherein the cell voltage ranges from about 2.5 to 3.5 volts, at a cathode current density of about 5 to 20 amps/sq.ft. and at a temperature ranging from about 50° C. to 80° C.
Claim 9
Dependent Claim
28 words
The method of claim 5, wherein as the pH rises during dissolution, sulfuric acid is added to control the pH over the range of about 0.8 to 1.2.
References Cited (Backward Citations)
US3673062A
Cited
US3933976A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-19 | 1983-05-21 | 1983-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-19 | 1987-05-21 | 1987-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-19 | 1991-05-21 | 1991-11-20 | $7700.00 | Window Closed / Lapsed |