US3798024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reclamation of aluminous skim
Assignee: Reynolds Metals Co
•
Filing: 1972-07-13
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Granted: 1974-03-19
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Expires: 1992-07-13
Abstract
Abstract Skim or dross material formed on a body of molten aluminum or aluminum alloy is treated to recover aluminous metal by removing the hot skim material to a preheated skim pot, introducing previously melted salt flux, stirring the flux and skim so as to admix them thoroughly, and recovering molten metal separated from the residual skim solids.
Inventors
- 👤 A Murphy
- 👤 K Hagerman
- 👤 N Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:57
CPC Classifications
C; C22; C22B; C22B21/00; C22B21/0038; C22B21/0069; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
Method for the recovery of aluminous metal from skim material comprising dross formed on the surface of a body of molten aluminum or aluminum base alloy, comprising the steps of: a. removing the skim material from said molten metal surface to a preheated container; b. introducing mOlten salt flux over the skim material in said container; c. stirring said skim material and molten flux for a period of time sufficient to cause separation of aluminous metal from the mixture; and d. recovering the molten aluminous metal, the initial temperature of the skim material and the skim container being sufficient to keep the separated aluminum in molten condition during stirring and metal recovery.
Claim 2
Dependent Claim
21 words
The method of claim 2 in which the salt flux consists essentially of a mixture of sodium chloride and potassium chloride.
Claim 3
Dependent Claim
15 words
The method of claim 3 in which said salt mixture is substantially a eutectic mixture.
Claim 4
Dependent Claim
42 words
The method of claim 3 in which said salt mixture further includes a member selected from the group consisting of cryolite, aluminum fluoride, an alkaline earth metal fluoride and an alkali metal fluoride, and a combination of at least two such members.
Claim 5
Dependent Claim
28 words
The method of claim 2 in which the salt flux consists essentially of approximately 50 percent sodium chloride, 45 percent potassium chloride and 5 percent cryolite, by weight.
Claim 6
Dependent Claim
23 words
The method of claim 2 in which the skim container contents are maintained at a temperature between about 1,200* and about 1, 600*F.
Claim 7
Dependent Claim
21 words
The method of claim 1 in which the molten flux is preheated to a temperature from about 1,400*F. to about 1,600*F.
Claim 8
Dependent Claim
26 words
The method of claim 1 in which the proportion of salt flux to skim material is between about 20 percent and about 30 percent by weight.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |