Patent US4442072A successfully refreshed from Google Patents.
US4442072A
Expired / Lapsed
US
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Selective recovery of base metals and precious metals from ores
Assignee: United States Department of the Interior
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Filing: 1982-10-20
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Granted: 1984-04-10
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Expires: 2002-10-20
Abstract
Abstract Metal values are recovered from ore concentrates by forming a sulfide matte, grindng the matte, leaching with sulfuric acid at elevated temperature to selectively extract nickel and iron, and roasting and leaching the residue with dilute sulfuric acid to selectively extract copper. The residue contains a high concentration of platinum, palladium and gold.
Inventors
- 👤 Elizabeth G. Baglin
- 👤 John M. Gomes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:29
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/04; C22B15/00; C22B15/0002; C22B15/001; C22B15/0026; C22B15/0028; C22B15/0063; C22B15/0065; C22B15/0067; C22B15/0071; C22B23/00; C22B23/02; C22B23/025; C22B23/04; C22B23/0407; C22B23/0415; C22B23/043; C22B5/00; C22B5/02; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
139 words
A process for recovery of nickel, iron, copper, platinum, palladium and gold values from ore concentrates consisting essentially of: (a) smelting the concentrate with a flux to form a matte and slag, (b) grinding the matte to a particle size suitable for leaching, (c) leaching, in a first-stage, the ground matte with sulfuric acid of a concentration of about 10 to 40 wt-pct at a temperature of about 40° to 100° C. and atmospheric pressure to selectively extract nickel and iron values, and (d) roasting and leaching, in a second-stage, the residue from the first-stage leach, the roasting being at a temperature of about 300° to 500° C., and the leaching being with dilute sulfuric acid at ambient temperature and pressure, to selectively extract copper values and provide a residue containing a high concentration of platinum, palladium and gold.
Claim 2
Dependent Claim
139 words
A process for recovery of nickel, iron, copper, platinum, palladium and gold values from ore concentrates consisting essentially of: (a) smelting the concentrate with a flux to form a matte and slag, (b) grinding the matte to a particle size suitable for leaching, (c) leaching, in a first-stage, the ground matte with sulfuric acid of a concentration of about 10 to 40 wt-pct at a temperature of about 40° to 100° C. and atmospheric pressure to selectively extract nickel and iron values, and (d) roasting and leaching, in a second-stage, the residue from the first-stage leach, the roasting being at a temperature of about 300° to 500° C., and the leaching being with dilute sulfuric acid at ambient temperature and pressure, to selectively extract copper values and provide a residue containing a high concentration of platinum, palladium and gold.
Claim 3
Dependent Claim
15 words
The process of claim 1 in which the ore is a Stillwater complex sulfide ore.
Claim 4
Dependent Claim
39 words
The process of claim 1 in which the roasting in step (d) is at a temperature of about 330° to 400° C., and the leaching is accomplished with sulfuric acid of a concentration of about 0.2 to 1 molar.
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) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |