US3642435A
Expired / Lapsed
US
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Method of recovering water-soluble nonferrous metal sulfates from sulfur-bearing ores
Assignee: Cyprus Mines Corp
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Filing: 1969-11-10
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Granted: 1972-02-15
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Expires: 1989-11-10
Abstract
Abstract Ore with a relatively high sulfur content, containing various amounts of ferrous and nonferrous sulfides, and particularly a relatively small amount of copper sulfide, is subjected to a controlled oxidation leach in an aqueous medium at elevated temperatures and pressures, to convert the nonferrous sulfides into water-soluble sulfates with only slight concomitant oxidation of the ferrous sulfides.
Inventors
- 👤 Eugene S Allen
- 👤 Royce S Gavrias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:20
CPC Classifications
C; C01; C01G; C01G3/00; C01G3/10; C22; C22B; C22B3/00; C22B3/04; C22B3/06; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
26 words
The method defined in claim 1 in which the sulfur values content as percent sulfur of the slurry''s solids is at least 6 percent by weight.
Claim 2
Dependent Claim
22 words
The method defined in claim 1 in which the solids content of the slurry is between about 25 and about 30 percent.
Claim 3
Dependent Claim
21 words
The Method defined in claim 1 in which the temperature during the oxidative leaching step is maintained at about 180* F.
Claim 4
Dependent Claim
31 words
The method defined in claim 1 in which the oxygen-containing gas is air which is passed through the slurry during the oxidative leaching step at a pressure of about 90 p.s.i.g.
Claim 5
Dependent Claim
39 words
The method defined in claim 1 in which the oxygen-containing gas is air which is injected into the slurry below the surface thereof at a rate of about 170 cubic feet per minute per 1,000 cubic feet of slurry.
Claim 6
Dependent Claim
32 words
The method defined in claim 6 in which the off gases are bled from the slurry at a rate of about 170 cubic feet per minute per 1,000 cubic feet of slurry.
Claim 7
Dependent Claim
18 words
The method defined in claim 1 in which the residence time of the leach is about 3 hours.
Claim 8
Dependent Claim
38 words
The method defined in claim 1 in which following the oxidative leaching step the slurry is cooled and filtered; the resulting filtered solid residue is washed with water; and the resulting washings are added to the slurry filtrate.
Claim 9
Independent Claim
245 words
The method of selectively recovering soluble nonferrous metal sulfates from sulfur-bearing pyrite ores with a minimal conversion of the pyrite and production of elemental sulfur, sulfuric acid and soluble iron sulfate values, which includes the steps of: providing an aqueous slurry by mixing water and finely divided sulfur-bearing pyrite ore which contains nonferrous metal sulfides, the slurry containing a sufficient amount of sulfur values to form soluble sulfates of the nonferrous metals and produce ferric sulfate and sulfuric acid, solids content of the slurry being from about 25 to about 30 percent; and subjecting the slurry to an oxidative leaching step for about 3 hours by heating the slurry to a temperature of from about 175* to about 250* F. and passing air through the slurry under a pressure of about 90 p.s.i.g. so that the nonferrous metal sulfides are converted to soluble nonferrous metal sulfates, the air being injected into the slurry below the surface thereof at the rate of about 170 cubic feet per minute per 1, 000 cubic feet of slurry, so that the conversion of pyrite is minimized and the concentration of sulfuric acid and the concentration of ferric sulfate are both maintained below 50 grams per liter of slurry, said heated slurry containing sufficient amounts of sulfate sulfur values, as ferric sulfate, to form soluble sulfates of the nonferrous metals, and sufficient amounts of sulfide sulfur values, as pyrite, to maintain an adequate amount of sulfate sulfur, as ferric sulfate.
Claim 10
Dependent Claim
26 words
The method defined in claim 10 in which the sulfur values content, as percent sulfur, of the slurry''s solids is at least 6 percent by weight.
Claim 11
Dependent Claim
34 words
The method defined in claim 10 in which the off gas is removed at a rate of about 170 cubic feet per minute per 1,000 cubic feet of slurry, during the oxidative leaching step.
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) | 1975-02-14 | 1975-08-16 | 1976-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-14 | 1979-08-16 | 1980-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-14 | 1983-08-16 | 1984-02-15 | $7700.00 | Window Closed / Lapsed |