Patent US3999980A successfully refreshed from Google Patents.
US3999980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluxless recovery of metallic aluminum from wastes
Assignee: United States Department of the Interior
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Filing: 1975-05-09
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Granted: 1976-12-28
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Expires: 1995-05-09
Abstract
Abstract Aluminum metal is recovered from processing wastes, such as dross, beverage can scrap and the like, without use of a flux by heating the wastes to a temperature above the melting point of aluminum but below about 800 DEG C while maintaining the wastes under a protective gaseous atmosphere which is substantially inert to molten aluminum. After melting of aluminum contained in the wastes is complete, the heated material is agitated gently to agglomerate the molten aluminum and to cause its settling and collection in the bottom of the containment vessel. Molten aluminum is thereafter removed from the vessel leaving a substantially inert residue. Argon is preferred as the protective atmosphere.
Inventors
- 👤 Dominic Montagna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:43
CPC Classifications
C; C22; C22B; C22B21/00; C22B21/0084; C22B21/0092; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
A method for reclaiming aluminum metal from aluminum dross contaminated with non-metallic impurities which comprises: heating said aluminum dross under an inert gaseous atmosphere in the absence of flux to a temperature above the melting point of aluminum but below 800° C for a time sufficient to melt all of the metal contained in the dross; subjecting the dross to gentle agitation for a time sufficient to agglomerate the molten aluminum and to cause separation of molten aluminum from other constituents of the dross, and recovering a metallic aluminum product having a composition substantially the same as the metallic portion of said dross.
Claim 2
Dependent Claim
12 words
The process of claim 1 wherein said inert gaseous atmosphere is argon.
Claim 3
Dependent Claim
24 words
The process of claim 1 wherein the dross is heated to a temperature above the melting point of aluminum but below about 750° C.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said gentle agitation comprises stirring.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein said gentle agitation comprises rotation of a vessel containing said dross.
Claim 6
Dependent Claim
37 words
The process of claim 1 wherein a dross residue comprising aluminum oxides, remaining after recovery of the aluminum product, is cooled, crushed and subjected to a physical sizing step to recover a fine and a coarse fraction.
Claim 7
Dependent Claim
25 words
The process of claim 6 wherein said course fraction is recycled to said heating step and wherein said fine fraction is rejected from the process.
Claim 8
Dependent Claim
15 words
The process of claim 7 wherein said coarse fraction is larger than about 20 mesh.
References Cited (Backward Citations)
US969253A
Cited
US1160430A
Cited
US2754199A
Cited
US3649247A
Cited
US3770424A
Cited
US3848813A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-12-28 | 1980-06-28 | 1980-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-28 | 1984-06-28 | 1984-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-28 | 1988-06-28 | 1988-12-28 | $7700.00 | Window Closed / Lapsed |