US3929468A
Expired / Lapsed
US
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Process for recovery of non-ferrous metals from oxide ores and concentrates
Assignee: United States Department of the Interior
•
Filing: 1975-01-02
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Granted: 1975-12-30
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Expires: 1995-01-02
Abstract
Abstract Nickel, cobalt and copper are recovered from oxide ores and oxide ore concentrates, especially those ores and concentrates containing substantial amounts of iron oxides, by selectively reducing the non-ferrous metal oxides to their elemental state in the absence of water vapor at temperatures ranging from 350*C to 600*C using carbon monoxide as the sole reductant. The reduced ore is then cooled and subjected to an oxidizing leach using an aqueous ammonia-ammonium sulfate solution as the leaching medium. Leaching is controlled in such a fashion that the non-ferrous metals are oxidized and stabilized in solution as their ammine complexes prior to the occurrence of any substantial oxidation of ferrous iron to the ferric state. Non-ferrous metal values are then separately recovered from the leach solution by techniques such as solvent extraction and precipitation. The process allows recovery of more than 90% of the nickel and more than 85% of the cobalt from laterite ores.
Inventors
- 👤 Richard E Siemens
- 👤 Philip C Good
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:20
CPC Classifications
C; C22; C22B; C22B23/00; C22B23/04; C22B23/0407; C22B23/0446; C22B15/00; C22B15/0002; C22B15/001; C22B15/0021; C22B15/0063; C22B15/0065; C22B15/0078; C22B15/0084; C22B15/0089; C22B15/0093; C22B23/005; C22B47/00; C22B47/0018; C22B47/0027; C22B47/0045; C22B47/0054; C22B47/0072; C22B5/00; C22B5/02; C22B5/12; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S423/00; Y10S423/04
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
209 words
A PROCESS FOR THE RECOVERY OF NICKEL FROM LATERITE ORES WHICH COMPRISES: COMMINUTING SAID LATERITE ORE TO A FINELY DIVIDED STATE; PELLETIZING SAID COMMINUTED ORE, DRYING THE PELLETIZED ORE AT A TEMPERATURE SUFFICIENTLY HIGH TO DRIVE OFF ALL FREE MOISTURE AND LIMONITIC WATER BUT AT A TEMPERATURE SUFFICIENTLY LOW SO AS NOT TO DRIVE OFF CHEMICALLY COMBINED SILICATE WATER; CONTACTING THE DRIED ORE WITH A REDUCTANT GAS CONSISTING ESSENTIALLY OF CARBON MONOXIDE AT A TEMPERATURE IN THE RANGE OF 350*TO 600*C FOR A TIME SUFFICIENT TO REDUCE SUBSTANTIALLY ALL NICKEL OXIDE CONTAINED IN THE ORE TO ELEMENTAL METAL; COOLING THE REDUCED ORE TO A TEMPERATURE BELOW ABOUT 200*C IN AN OXYGEN AND WATER-FREE ENVIRONMENT; MIXING SAID COOLED ORE WITH A LEACH SOLUTION COMPRISING AN AQUEOUS AMMONIA-AMMONIUM SULFATE SOLUTION, SAID MIXING BEING COUPLED WITH ATTRITION SUFFICIENTLY INTENSE TO DISINTEGRATE THE ORE PELLETS AND TO FORM A SUSPENSION OF REDUCED ORE IN THE LEACH SOLUTION; CONTACTING SAID SUSPENSION WITH GASEOUS OXYGEN FOR A TIME SUFFICIENT TO OXIDIZE SUBSTANTIALLY ALL OF THE ELEMENTAL NICKEL CONTAINED IN THE REDUCED ORE AND TO STABILIZE THE OXIDIZED NICKEL IN THE LEACH SOLUTION AS ITS DIVALENT AMMINE COMPLEX; SEPARATING THE NICKEL CONTAINING LEACH SOLUTION FROM THE ORE RESIDUE; AND RECOVERING NICKEL VALUES FROM SAID LEACH SOLUTION.
Claim 2
Dependent Claim
209 words
A PROCESS FOR THE RECOVERY OF NICKEL FROM LATERITE ORES WHICH COMPRISES: COMMINUTING SAID LATERITE ORE TO A FINELY DIVIDED STATE; PELLETIZING SAID COMMINUTED ORE, DRYING THE PELLETIZED ORE AT A TEMPERATURE SUFFICIENTLY HIGH TO DRIVE OFF ALL FREE MOISTURE AND LIMONITIC WATER BUT AT A TEMPERATURE SUFFICIENTLY LOW SO AS NOT TO DRIVE OFF CHEMICALLY COMBINED SILICATE WATER; CONTACTING THE DRIED ORE WITH A REDUCTANT GAS CONSISTING ESSENTIALLY OF CARBON MONOXIDE AT A TEMPERATURE IN THE RANGE OF 350*TO 600*C FOR A TIME SUFFICIENT TO REDUCE SUBSTANTIALLY ALL NICKEL OXIDE CONTAINED IN THE ORE TO ELEMENTAL METAL; COOLING THE REDUCED ORE TO A TEMPERATURE BELOW ABOUT 200*C IN AN OXYGEN AND WATER-FREE ENVIRONMENT; MIXING SAID COOLED ORE WITH A LEACH SOLUTION COMPRISING AN AQUEOUS AMMONIA-AMMONIUM SULFATE SOLUTION, SAID MIXING BEING COUPLED WITH ATTRITION SUFFICIENTLY INTENSE TO DISINTEGRATE THE ORE PELLETS AND TO FORM A SUSPENSION OF REDUCED ORE IN THE LEACH SOLUTION; CONTACTING SAID SUSPENSION WITH GASEOUS OXYGEN FOR A TIME SUFFICIENT TO OXIDIZE SUBSTANTIALLY ALL OF THE ELEMENTAL NICKEL CONTAINED IN THE REDUCED ORE AND TO STABILIZE THE OXIDIZED NICKEL IN THE LEACH SOLUTION AS ITS DIVALENT AMMINE COMPLEX; SEPARATING THE NICKEL CONTAINING LEACH SOLUTION FROM THE ORE RESIDUE; AND RECOVERING NICKEL VALUES FROM SAID LEACH SOLUTION.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein said leach solution contains from about 25 to 150 gpl ammonia and from about 50 to 400 gpl ammonium sulfate.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein the binding agent in said pelletizing step is water.
Claim 5
Dependent Claim
14 words
The process of claim 2 wherein said gaseous oxygen is substantially free of impurities.
Claim 6
Dependent Claim
30 words
The process of claim 4 wherein said step of contacting the suspension of reduced ore and leach solution is carried out at temperatures in the range of 5* to 50*C.
Claim 7
Dependent Claim
32 words
The process of claim 5 wherein said laterite ore also contains cobalt and wherein said cobalt is oxidized to the trivalent state and stabilized in the leach solution as its amine complex.
Claim 8
Dependent Claim
37 words
The process of claim 6 wherein the concentration of ammonium sulfate in said leach solution is at least double that of ammonia and wherein the sum of the concentrations of ammonium sulfate and ammonia exceeds 200 gpl.
Claim 9
Dependent Claim
20 words
The process of claim 7 wherein nickel is selectively recovered from the nickel and cobalt-containing leach solution by solvent extraction.
Claim 10
Dependent Claim
23 words
The process of claim 8 wherein the extractant used in said solvent extraction is an Alpha -hydroxy oxime dissolved in a hydrocarbon solvent.
Claim 11
Dependent Claim
28 words
The process of claim 5 wherein the dried ore is contacted with carbon monoxide in multiple stages with carbon monoxide being passed in counterflow relationship to the ore.
Claim 12
Dependent Claim
29 words
The process of claim 10 wherein the drying temperature of the pelletized ore is essentially the same as the temperature at which dried ore is contacted with carbon monoxide.
Claim 13
Dependent Claim
21 words
The process of claim 11 wherein said drying temperature and said contacting temperature are in the range of 450* to 550*C.
Claim 14
Dependent Claim
44 words
The process of claim 10 wherein reactant gases produced by the contacting of dried ore with carbon monoxide are passed through a coke bed maintained at a temperature above about 1050*C to produce a carbon monoxide stream suitable for use in reducing additional ore.
Claim 15
Dependent Claim
21 words
The process of claim 13 wherein said carbon monoxide stream produced by reaction with coke has a purity greater than 99%.
Claim 16
Dependent Claim
42 words
The process of claim 10 wherein said laterite ore contains more that about 5% magnesia and wherein pyrite in an amount greater than 0.5% by weight of said ore is mixed with said ore prior to contacting the ore with carbon monoxide.
Claim 17
Dependent Claim
28 words
The process of claim 15 wherein said laterite ore is limonitic and wherein pyrite addition is in the range of 0.5 to 2.5% by weight of said ore.
Claim 18
Dependent Claim
31 words
The process of claim 15 wherein said laterite ore is serpentine and wherein pyrite is added in an amount greater than 0.5% but less than 10% by weight of said ore.
Claim 19
Dependent Claim
28 words
The process of claim 1 wherein said ore residue is subjected to a magnetic separation to recover an iron oxide concentrate suitable for use as an iron ore.
Claim 20
Dependent Claim
16 words
The process of claim 18 wherein said magnetic separation is a high intensity, wet magnetic separation.
Claim 21
Dependent Claim
121 words
A process for the selective reduction of non-ferrous metals associated with iron in an oxide ore, said non-ferrous metals selected from the group consisting of nickel, cobalt, copper mixtures thereof, which comprises: contacting said ore with a reducing gas consisting essentially of carbon monoxide at a temperature in the range of 350* to 600*C for a time sufficient to reduce substantially all of said non-ferrous metals to the elemental state, said contacting being performed in the absence of water vapor; removing said ore From contact with the reducing gas before substantial reduction of iron oxides to metallic iron occurs; and cooling said reduced ore to a temperature below about 200*C in an inert atmosphere prior to performing any subsequent processing steps.
Claim 22
Dependent Claim
121 words
A process for the selective reduction of non-ferrous metals associated with iron in an oxide ore, said non-ferrous metals selected from the group consisting of nickel, cobalt, copper mixtures thereof, which comprises: contacting said ore with a reducing gas consisting essentially of carbon monoxide at a temperature in the range of 350* to 600*C for a time sufficient to reduce substantially all of said non-ferrous metals to the elemental state, said contacting being performed in the absence of water vapor; removing said ore From contact with the reducing gas before substantial reduction of iron oxides to metallic iron occurs; and cooling said reduced ore to a temperature below about 200*C in an inert atmosphere prior to performing any subsequent processing steps.
Claim 23
Dependent Claim
52 words
The process of claim 20 wherein said reduced ore, after being cooled below about 200*C, is slurried in an aqueous ammonia-ammonium salt leach solution and is thereafter contacted with gaseous oxygen for a time sufficient to oxidize substantially all of the non-ferrous metals and stabilize them in solution as their amine complexes.
Claim 24
Dependent Claim
12 words
The process of claim 21 wherein the ammonium salt is ammonium sulfate.
Claim 25
Dependent Claim
26 words
The process of claim 22 wherein said leach solution contains from about 25 to 150 g/l ammonia and from about 50 to 400 g/l ammonium sulfate.
Claim 26
Dependent Claim
34 words
The process of claim 23 wherein said reduced ore slurried in leach solution is contacted with substantially pure gaseous oxygen at a temperature in the range of 5* to 50*C at substantially atmosphperic pressure.
Claim 27
Dependent Claim
26 words
The process of claim 24 wherein said oxide ore is selected from the group consisting of the naturally occurring oxide ores of nickel, cobalt and copper.
Claim 28
Dependent Claim
13 words
The process of claim 25 wherein said oxide ore is a nickel-containing laterite.
Claim 29
Dependent Claim
23 words
The process of claim 25 wherein said oxide ore contains copper and is selected from the group consisting of chrysocolla azurite and malachite.
Claim 30
Dependent Claim
14 words
The process of claim 25 wherein said oxide ore is an ocean floor nodule.
Claim 31
Dependent Claim
18 words
The process of claim 24 wherein said oxide ore comprises a dead roasted calcine of a sulfide ore.
Claim 32
Dependent Claim
168 words
A process for recoverying non-ferrous metal values from a reduced ore containing iron in elemental form and at least one other elemental metal selected from the group consisting of nickel, cobalt and copper, which comprises: forming a suspension of said reduced ore in an aqueous leach solution containing 25 to 150 gpl ammonia and 50 to 400 gpl ammonium sulfate; contacting said suspension of reduced ore and leach solution with gaseous oxygen at a temperature in the range of 5* to 50*C; maintaining the rate of oxygen introduction in said contacting step at a level below 50% of the maximum rate at which oxygen can react with the reduced ore until at least 90% of the reduced non-ferrous metals are oxidized and stabilized within the leach solution as their ammine complexes; thereafter, continuing oxygen introduction until substantially all of the reduced iron is oxidized to the ferric state and is precipitated as a hydrous ferric oxide; and separating leach solution, now containing non-ferrous metals, from the ore residue.
Claim 33
Dependent Claim
168 words
A process for recoverying non-ferrous metal values from a reduced ore containing iron in elemental form and at least one other elemental metal selected from the group consisting of nickel, cobalt and copper, which comprises: forming a suspension of said reduced ore in an aqueous leach solution containing 25 to 150 gpl ammonia and 50 to 400 gpl ammonium sulfate; contacting said suspension of reduced ore and leach solution with gaseous oxygen at a temperature in the range of 5* to 50*C; maintaining the rate of oxygen introduction in said contacting step at a level below 50% of the maximum rate at which oxygen can react with the reduced ore until at least 90% of the reduced non-ferrous metals are oxidized and stabilized within the leach solution as their ammine complexes; thereafter, continuing oxygen introduction until substantially all of the reduced iron is oxidized to the ferric state and is precipitated as a hydrous ferric oxide; and separating leach solution, now containing non-ferrous metals, from the ore residue.
Claim 34
Dependent Claim
14 words
The process of claim 30 wherein said gaseous oxygen is essentially free of impurities.
Claim 35
Dependent Claim
25 words
The process of claim 31 wherein the oxygen is introduced as a dispersion of fine bubbles at a point near the bottom of said suspension.
Claim 36
Dependent Claim
44 words
The process of claim 31 wherein said contacting is accomplished in at least two stages and wherein at least 90% of the reduced non-ferrous metals are oxidized and stabilized within the leach solution as their ammine complexes in the first stage of said contacting.
Claim 37
Dependent Claim
44 words
The process of claim 33 wherein leach solution is separated from the ore at the conclusion of the first stage of said contacting and wherein the ore is re-suspended in fresh leach solution and is again contacted with gaseous oxygen in a second stage.
Claim 38
Dependent Claim
32 words
The process of claim 34 wherein the rate of oxygen introduction in said first stage is less than 25% of the maximum rate at which oxygen can react with the reduced ore.
Claim 39
Dependent Claim
33 words
The process of claim 34 wherein the rate of oxygen introduction in said second stage is equal to or greater than the maximum rate at which oxygen can react with the reduced ore.
Claim 40
Dependent Claim
51 words
The process of claim 34 wherein leach solution separated from the ore at the conclusion of said first stage contacting is contacted with oxygen for a time sufficient to oxidize soluble ferrous iron contained in the leach solution to the ferric state thereby precipitating said iron as a hydrous ferric oxide.
Claim 41
Dependent Claim
58 words
The process of claim 34 wherein leach solution is separated from the ore residue at the conclusion of said second stage contacting and wherein said ore residue is first washed with aqueous ammonium hydroxide, then with water and is thereafter subjected to a magnetic separation to recover an iron oxide concentrate suitable for use as an iron ore.
Claim 42
Dependent Claim
13 words
The process of claim 31 wherein said reduced ore is a nickel-containing laterite.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |