US4067731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating molten metal
Assignee: Southwire Co LLC
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Filing: 1976-06-07
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Granted: 1978-01-10
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Expires: 1996-06-07
Abstract
Abstract A method of treating molten aluminum and aluminum alloys to remove solid and gaseous impurities therefrom is disclosed. Molten metal is flowed through an integrated series of successively arranged purification stages including a deslagging stage wherein relatively large particulate impurities are removed from the molten metal by filtering the same through a woven refractory filter, a fluxing stage for removing entrapped and dissolved hydrogen from the molten metal, an adsorption stage wherein the molten metal is passed over a plurality of impurity-adsorbing refractory plates and a final filtration stage wherein the finer particulate impurities are removed by filtering the molten metal through a rigid, porous refractory filter medium.
Inventors
- 👤 Enrique C. Chia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:10
CPC Classifications
C; C22; C22B; C22B21/00; C22B21/06; C22B21/066; C22B9/00; C22B9/05; C22B9/055
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
95 words
A method of continuously treating molten aluminum and aluminum alloys to remove impurities and gases therefrom comprising the steps of: a. deslagging by filtering the molten aluminum to remove relatively large size solid impurities therefrom; b. fluxing the molten aluminum to remove hydrogen gas therefrom; c. adsorbing selected impurities by passing the molten aluminum over an adsorptive refractory material having an adsorptive affinity for said selected impurities in the molten aluminum; and d. filtering the molten aluminum through a rigid porous refractory filter medium to remove impurities not removed in said deslagging and adsorbing steps.
Claim 2
Independent Claim
95 words
A method of continuously treating molten aluminum and aluminum alloys to remove impurities and gases therefrom comprising the steps of: a. deslagging by filtering the molten aluminum to remove relatively large size solid impurities therefrom; b. fluxing the molten aluminum to remove hydrogen gas therefrom; c. adsorbing selected impurities by passing the molten aluminum over an adsorptive refractory material having an adsorptive affinity for said selected impurities in the molten aluminum; and d. filtering the molten aluminum through a rigid porous refractory filter medium to remove impurities not removed in said deslagging and adsorbing steps.
Claim 3
Dependent Claim
26 words
Method according to claim 1 wherein the step of fluxing the molten metal includes passing a fluxing gas in counter-current relation to the molten metal flow.
Claim 4
Dependent Claim
29 words
Method according to claim 1 wherein the step of deslagging by filtering the molten aluminum includes filtering the molten metal through a filter medium fabricated of woven refractory filaments.
Claim 5
Dependent Claim
41 words
Method according to claim 2 wherein the fluxing step further includes the step of directing the molten metal flow in alternate, substantially vertical directions and passing the fluxing gas countercurrently through the molten metal when the flow is substantially downwardly directed.
Claim 6
Dependent Claim
19 words
Method according to claim 4 including the step of passing fluxing gas at least twice through the molten metal.
Claim 7
Dependent Claim
38 words
Method according to claim 1 wherein the step of adsorbing selected impurities includes flowing the molten aluminum over a plurality of spaced, parallel refractory plates arranged in parallel relation to the direction of flow of the molten metal.
Claim 8
Dependent Claim
43 words
The method according to claim 1 wherein said adsorptive refractory material is selected from the group consisting of aluminum oxide, calcium oxide, mullite, and silicon carbide and wherein said impurities comprise solid particulate matter in the form of oxide particles and entrapped gases.
Claim 9
Dependent Claim
42 words
The method according to claim 2 wherein the step of passing a fluxing gas through the molten metal includes the step of providing a fluxing gas selected from the group consisting of chlorine, nitrogen, argon or other inert gas and mixtures thereof.
Claim 10
Independent Claim
173 words
A method of continuously fluxing and filtering molten aluminum and aluminum alloys to remove impurities and gases therefrom comprising the steps of: a. deslagging the molten aluminum to remove relatively large size solid impurities therefrom by filtering the molten aluminum through at least one filter woven of refractory filaments; b. fluxing the molten aluminum to remove hydrogen gas therefrom by flowing a gas in countercurrent flow through the molten aluminum in a first flow channel and subsequently flowing a gas in countercurrent flow through the molten aluminum in a second flow channel; c. adsorbing selected impurities in the molten aluminum by flowing the molten aluminum in thin, unidirectional streams over a plurality of spaced, parallel plates fabricated of a refractory material having an adsorptive affinity for said selected impurities in the molten aluminum; d. filtering the molten aluminum to remove impurities not removed in said deslagging and adsorbing steps by passing the molten aluminum through a rigid, porous refractory filter having an undulating shape formed by a plurality of interconnected, horizontally disposed channels.
Claim 11
Independent Claim
173 words
A method of continuously fluxing and filtering molten aluminum and aluminum alloys to remove impurities and gases therefrom comprising the steps of: a. deslagging the molten aluminum to remove relatively large size solid impurities therefrom by filtering the molten aluminum through at least one filter woven of refractory filaments; b. fluxing the molten aluminum to remove hydrogen gas therefrom by flowing a gas in countercurrent flow through the molten aluminum in a first flow channel and subsequently flowing a gas in countercurrent flow through the molten aluminum in a second flow channel; c. adsorbing selected impurities in the molten aluminum by flowing the molten aluminum in thin, unidirectional streams over a plurality of spaced, parallel plates fabricated of a refractory material having an adsorptive affinity for said selected impurities in the molten aluminum; d. filtering the molten aluminum to remove impurities not removed in said deslagging and adsorbing steps by passing the molten aluminum through a rigid, porous refractory filter having an undulating shape formed by a plurality of interconnected, horizontally disposed channels.
Claim 12
Dependent Claim
23 words
Method according to claim 9 wherein the molten aluminum is discharged into the tundish of a continuous casting machine after treating said metal.
Claim 13
Dependent Claim
140 words
An improved method of continuously treating molten metal to remove impurities therefrom wherein the improvement comprises the steps of: a. deslagging the molten metal to remove relatively large sized solid impurities therefrom by filtering said metal through at least one filter woven of refractory filaments; b. fluxing the molten metal by flowing a gas selected from the group consisting of chlorine, nitrogen, argon or other inert gas and mixtures thereof, through the molten metal, c. adsorbing selected impurities by passing the molten metal over an adsorptive refractory material selected from the group consisting of aluminum oxide, calcium oxide, mullite, and silicon carbide, said selected material having an affinity for said selected impurities in the molten metal; and d. filtering the molten metal through a rigid porous refractory filter medium to remove impurities not removed in said deslagging and adsorbing steps.
Claim 14
Dependent Claim
140 words
An improved method of continuously treating molten metal to remove impurities therefrom wherein the improvement comprises the steps of: a. deslagging the molten metal to remove relatively large sized solid impurities therefrom by filtering said metal through at least one filter woven of refractory filaments; b. fluxing the molten metal by flowing a gas selected from the group consisting of chlorine, nitrogen, argon or other inert gas and mixtures thereof, through the molten metal, c. adsorbing selected impurities by passing the molten metal over an adsorptive refractory material selected from the group consisting of aluminum oxide, calcium oxide, mullite, and silicon carbide, said selected material having an affinity for said selected impurities in the molten metal; and d. filtering the molten metal through a rigid porous refractory filter medium to remove impurities not removed in said deslagging and adsorbing steps.
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) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |