US4337226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of platinum-group metals from ores
Assignee: United States Department of the Interior
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Filing: 1981-02-11
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Granted: 1982-06-29
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Expires: 2001-02-11
Abstract
Abstract Metal values are recovered from ore concentrates by means of dry grinding, followed by a two-stage leaching process in which the ground concentrate is first leached with sulfuric acid at a temperature of about 90 DEG to 100 DEG C. to selectively leach nickel and iron. The residue is then leached with a solution comprising sulfuric acid and NaOCl or H2O2 to extract platinum, palladium, copper and gold.
Inventors
- 👤 Edward R. Peasley
- 👤 John M. Gomes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:55
CPC Classifications
C; C22; C22B; C22B3/00; C22B3/04; C22B3/06; C22B3/08; C22B11/00; C22B11/04; C22B15/00; C22B15/0063; C22B15/0065; C22B15/0067; C22B15/0071; C22B15/0084; C22B15/0089; C22B23/00; C22B23/02; C22B23/025; C22B23/04; C22B23/0407; C22B23/0415; C22B23/043; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
143 words
A process for recovery of nickel, iron, platinum, palladium, copper and gold values from ore concentrates consisting essentially of (a) smelting the concentrate with a flux to form a matte and slag; (b) dry grinding the matte to a particle size suitable for leaching; (c) leaching, in a first-stage leach, the ground matte with sulfuric acid of a concentration of about 15 to 25 weight percent at a temperature of about 90 to 100° C. and at atmospheric pressure to selectively extract nickel and iron values, and (d) leaching, in a second-stage leach, the residue from the first-stage leach with a leach solution comprising sulfuric acid of a concentration of about 20 to 30 weight percent and sodium hypochlorite or hydrogen peroxide, at a temperature of about 90° to 100° C. and at atmospheric pressure, to extract platinum, palladium, copper and gold values.
Claim 2
Dependent Claim
143 words
A process for recovery of nickel, iron, platinum, palladium, copper and gold values from ore concentrates consisting essentially of (a) smelting the concentrate with a flux to form a matte and slag; (b) dry grinding the matte to a particle size suitable for leaching; (c) leaching, in a first-stage leach, the ground matte with sulfuric acid of a concentration of about 15 to 25 weight percent at a temperature of about 90 to 100° C. and at atmospheric pressure to selectively extract nickel and iron values, and (d) leaching, in a second-stage leach, the residue from the first-stage leach with a leach solution comprising sulfuric acid of a concentration of about 20 to 30 weight percent and sodium hypochlorite or hydrogen peroxide, at a temperature of about 90° to 100° C. and at atmospheric pressure, to extract platinum, palladium, copper and gold values.
Claim 3
Dependent Claim
15 words
The process of claim 1 in which the ore is a Stillwater complex sulfide ore.
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) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |