US4152141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removal of alkali and alkaline earth metals from light metal melts
Assignee: Rio Tinto Switzerland AG
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Filing: 1978-09-27
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Granted: 1979-05-01
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Expires: 1998-09-27
Abstract
Abstract Alkali and alkaline earth metals are removed from light metal melts by causing the melt to flow through a bed consisting of granules of a mechanically resistant and chemically inert carrier particles which have a coating of carbon. A suitable granule is prepared by mixing particles of inert carrier material with a cokable carbonaceous material and heating the mixture in a closed reaction vessel to produce an adherent coating of carbon on the carrier particles of the granules. The density of the coated granules is greater than 2.5 g/cm3.
Inventors
- 👤 Alfred Steinegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:29
CPC Classifications
C; C22; C22B; C22B9/00; C22B9/02; C22B9/023; C22B21/00; C22B21/06; C22B21/066; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
A method of removal of alkali and alkaline earth metals from light metal melts which comprises establishing a coated granule bed consisting essentially of particles of mechanically inert carrier material having an adherent coating thereon of carbon, wherein the density of the coated granules is greater than 2.5 g/cm 3 , and causing said melt to flow through the bed.
Claim 2
Independent Claim
60 words
A method of removal of alkali and alkaline earth metals from light metal melts which comprises establishing a coated granule bed consisting essentially of particles of mechanically inert carrier material having an adherent coating thereon of carbon, wherein the density of the coated granules is greater than 2.5 g/cm 3 , and causing said melt to flow through the bed.
Claim 3
Dependent Claim
11 words
A method according to claim 1 wherein said melt is aluminum.
Claim 4
Dependent Claim
24 words
A method according to claim 1 wherein said inert carrier material has an adherent coating thereon of carbon 0.1 mm. to 10 mm. thick.
Claim 5
Dependent Claim
24 words
A method according to claim 1 including the step of causing a non-reactive gas to traverse the melt in counter-current relationship to the melt.
Claim 6
Dependent Claim
11 words
A method according to claim 4 wherein said gas is nitrogen.
Claim 7
Dependent Claim
16 words
A method according to claim 4 wherein said gas consists of at least one inert gas.
Claim 8
Dependent Claim
21 words
A method according to claim 6 wherein said gas contains 1 to 3 percent by volume of an aliphatic chloro-fluoro hydrocarbon.
Claim 9
Dependent Claim
19 words
A method according to claim 1 wherein the inert carrier particles are between 0.5 to 25 cm. in diameter.
Claim 10
Dependent Claim
16 words
A method according to claim 1 wherein the inert carrier material is an inert ceramic material.
Claim 11
Dependent Claim
25 words
A method according to claim 1 wherein the carrier is selected from the group consisting of corundum, magnesite, zirconium oxide, zirconium silicate, basalt, and bauxite.
Claim 12
Dependent Claim
28 words
A method according to claim 1 wherein the inert carrier is corundum and wherein the density of the coated granules is from 3.5 to 4.0 g/cm 3 .
Claim 13
Dependent Claim
31 words
A method according to claim 1 wherein the carbon coating is compact and wherein the coated particles are characterized by the absence of sintering together when arranged in a heated bed.
References Cited (Backward Citations)
US3281238A
Cited
US3528801A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-30 | 1982-10-30 | 1983-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-30 | 1986-10-30 | 1987-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-30 | 1990-10-30 | 1991-05-01 | $7700.00 | Window Closed / Lapsed |