US4409020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of metals from grinding sludges
Assignee: United States Department of the Interior
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Filing: 1983-01-24
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Granted: 1983-10-11
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Expires: 2003-01-24
Abstract
Abstract Metal values, such as Co, Ni, Cu and Fe, are recovered from magnet alloy grinding sludge by means of a process comprising: (1) treatment with an organic solvent to remove a major portion of sulfur and oil contaminants, (2) drying, grinding, sizing and magnetic separation to remove a major portion of grinding media contamination, (3) controlled oxidation-roasting to selectively remove residual sulfur and carbon, and (4) gaseous hydrogen reduction to deoxidize metal values.
Inventors
- 👤 James L. Holman, Jr.
- 👤 Leander A. Neumeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:02
CPC Classifications
C; C22; C22B; C22B1/00; C22B1/005; B; B03; B03C; B03C1/00; C22B5/00; C22B5/02; C22B5/12; C22B7/00; C22B7/001; C22B7/002; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
156 words
A process for recovery of metal values from magnet alloy grinding sludge comprising the sequential steps of: (1) removing a major portion of sulfur and oil contaminants from the sludge by means of an organic solvent, (2) drying the desulfurized and deoiled sludge at a temperature of about 90° to 105° C. for a period sufficient to remove substantially all remaining water and solvent, and obtain a dried product, (3) grinding the dried product for a period sufficient to partially free grinding abrasive material, (4) subjecting the ground product to sizing and magnetic separation to segregate a majority of the coarser abrasive material in a low-metallics nonmagnetic fraction, (5) oxidation-roasting of the sludge at a temperature of about 850° to 1,000° C. to selectively remove residual sulfur and carbon, and (6) subjecting the oxidized sludge to a gaseous hydrogen reduction at a temperature of about 1,050° to 1,2000° C. to reoxidize and recover purified metal values.
Claim 2
Dependent Claim
156 words
A process for recovery of metal values from magnet alloy grinding sludge comprising the sequential steps of: (1) removing a major portion of sulfur and oil contaminants from the sludge by means of an organic solvent, (2) drying the desulfurized and deoiled sludge at a temperature of about 90° to 105° C. for a period sufficient to remove substantially all remaining water and solvent, and obtain a dried product, (3) grinding the dried product for a period sufficient to partially free grinding abrasive material, (4) subjecting the ground product to sizing and magnetic separation to segregate a majority of the coarser abrasive material in a low-metallics nonmagnetic fraction, (5) oxidation-roasting of the sludge at a temperature of about 850° to 1,000° C. to selectively remove residual sulfur and carbon, and (6) subjecting the oxidized sludge to a gaseous hydrogen reduction at a temperature of about 1,050° to 1,2000° C. to reoxidize and recover purified metal values.
Claim 3
Dependent Claim
16 words
The process of claim 1 in which the metal values comprise Co, Ni, Cu and Fe.
Claim 4
Dependent Claim
13 words
The process of claim 1 in which the magnet alloy is Al-Ni-Co-bearing alloy.
Claim 5
Dependent Claim
12 words
The process of claim 1 in which the organic solvent is tetrachloroethylene.
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) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |