US3999979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of sulphur from molten metal
Assignee: British Steel Corp
•
Filing: 1975-11-24
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Granted: 1976-12-28
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Expires: 1995-11-24
Abstract
Abstract A system for desulphurizing molten iron in a two-zone vessel located at the foot of an inclined electromagnetic elevator. The molten metal together with added desulphurizing agent is agitated in the first zone of the vessel to thoroughly disperse the desulphurizing agent in the metal. The metal then passes to the second zone of the vessel where it is maintained in a quiescent state relative to the metal in the first zone, so that the slag floats to the surface of the metal and can be removed. The desulphurized metal is removed from the second zone of the vessel by means of the inclined electromagnetic conveyor.
Inventors
- 👤 Peter Outhwaite
- 👤 Neil Pigott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:01
CPC Classifications
C; C22; C22B; C22B9/00; C22B9/10; C21; C21C; C21C7/00; C21C7/04; C21C7/064; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/143
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
149 words
A method for reducing the sulphur content of molten metal including passing the molten metal into the first zone of a two zone vessel situated at the base of an inclined electromagnetic conveying trough, adding a desulphurising agent to the molten metal, agitating the molten metal and desulphurising agent in the first zone of said two zone vessel, passing the agitated metal into the second zone of said two zone vessel, the metal in the second zone being maintained in a quiescent condition relative to the metal in said first zone whereby to permit substantial separation of the slag formed in the reaction between the molten metal and the desulphurising agent from the molten metal, removing the slag from the upper surface of the metal, and electromagnetically elevating the metal of reduced sulphur content in the inclined conveying trough to remove it from the second zone of said vessel.
Claim 2
Independent Claim
149 words
A method for reducing the sulphur content of molten metal including passing the molten metal into the first zone of a two zone vessel situated at the base of an inclined electromagnetic conveying trough, adding a desulphurising agent to the molten metal, agitating the molten metal and desulphurising agent in the first zone of said two zone vessel, passing the agitated metal into the second zone of said two zone vessel, the metal in the second zone being maintained in a quiescent condition relative to the metal in said first zone whereby to permit substantial separation of the slag formed in the reaction between the molten metal and the desulphurising agent from the molten metal, removing the slag from the upper surface of the metal, and electromagnetically elevating the metal of reduced sulphur content in the inclined conveying trough to remove it from the second zone of said vessel.
Claim 3
Dependent Claim
40 words
A method according to claim 1 in which the desulphurising agent is added in particulate form in a carrier gas which is passed into the molten metal in the first zone by means of a lance submerged in the metal.
Claim 4
Dependent Claim
41 words
A method according to claim 1 in which the desulphurising agent in particulate form is introduced into the molten metal in a carrier gas passed through a tuyere built into the base or wall of the first zone of the vessel.
Claim 5
Dependent Claim
35 words
A method according to claim 1 in which the desulphurising agent is added in particulate from to the molten metal prior to the entry of the molten metal into the first zone of the vessel.
Claim 6
Dependent Claim
25 words
A method according to claim 4 in which the molten metal is passed through a vortex-inducing chamber before entering the first zone of the vessel.
Claim 7
Dependent Claim
15 words
A method according to claim 2 in which the carrier gas is a non-reactive gas.
Claim 8
Dependent Claim
32 words
A method according to claim 1 in which the agitation of the molten metal is carried out by means of a gas introduced under pressure into the first zone of the vessel.
Claim 9
Dependent Claim
28 words
A method according to claim 7 in which the gas is introduced through a porous plug in the base or wall of the first zone of the vessel.
Claim 10
Dependent Claim
15 words
A method according to claim 7 in which the agitating gas is a non-reactive gas.
Claim 11
Dependent Claim
26 words
A method according to claim 1 in which the first zone and the second zone of the vessel are divided by means of a single wier.
Claim 12
Dependent Claim
23 words
A method according to claim 1 in which the rate at which the metal is elevated in the electromagnetic conveying trough is determined.
Claim 13
Dependent Claim
50 words
A method according to claim 11 in which the determined rate of elevation of treated metal is fed back to the desulphurising agent addition stage, and the rate of input of the desulphurising agent is adjusted to maintain a substantially constant value for the sulphur content of the desulphurized metal.
Claim 14
Dependent Claim
24 words
A method according to claim 1 in which the desulphurising agent is selected from the following substances: powered lime, calcium carbide and soda ash.
Claim 15
Dependent Claim
155 words
Apparatus for reducing the sulphur content of molten metal including an inclined electromagnetic conveying trough and a vessel situated at the base thereof, means for dividing said vessel into two zones such that the first zone is adapted to receive molten metal and pass it to the second zone, the second zone being connected with the inclined electromagnetic conveying trough, means for adding a desulphurising agent to the molten metal prior to the passage of the molten metal through said first zone, means for agitating the molten metal and desulphurising agent in the first zone of the vessel whilst the metal in the second zone is maintained in a quiescent condition relative to that in the first zone by the dividing means, thereby permitting substantial separation of the slag formed in the reaction between the molten metal and the desulphurising agent from the molten metal before the molten metal is carried by the conveying trough.
Claim 16
Dependent Claim
155 words
Apparatus for reducing the sulphur content of molten metal including an inclined electromagnetic conveying trough and a vessel situated at the base thereof, means for dividing said vessel into two zones such that the first zone is adapted to receive molten metal and pass it to the second zone, the second zone being connected with the inclined electromagnetic conveying trough, means for adding a desulphurising agent to the molten metal prior to the passage of the molten metal through said first zone, means for agitating the molten metal and desulphurising agent in the first zone of the vessel whilst the metal in the second zone is maintained in a quiescent condition relative to that in the first zone by the dividing means, thereby permitting substantial separation of the slag formed in the reaction between the molten metal and the desulphurising agent from the molten metal before the molten metal is carried by the conveying trough.
Claim 17
Dependent Claim
154 words
Apparatus for reducing the sulfur content of molten metal including an inclined electromagnetic coveying trough and a vessel situated at the base thereof, means for dividing said vessel into two zones such that the first zone is adapted to receive molten metal and pass it to the second zone, the second zone being connected with the inclined electromagnetic conveying trough, means for adding a desulfurizing agent to the molten metal during the passage of the molten metal through said first zone, means for agitating the molten metal and desulfurizing agent in the first zone of the vessel whilst the metal in the second zone is maintained in a quiescent condition relative to that in the first zone by the dividing means, thereby permitting substantial separation of the slag formed in the reaction between the molten metal and the desulfurizing agent from the molten metal before the molten metal is carried by the conveying trough.
Claim 18
Dependent Claim
154 words
Apparatus for reducing the sulfur content of molten metal including an inclined electromagnetic coveying trough and a vessel situated at the base thereof, means for dividing said vessel into two zones such that the first zone is adapted to receive molten metal and pass it to the second zone, the second zone being connected with the inclined electromagnetic conveying trough, means for adding a desulfurizing agent to the molten metal during the passage of the molten metal through said first zone, means for agitating the molten metal and desulfurizing agent in the first zone of the vessel whilst the metal in the second zone is maintained in a quiescent condition relative to that in the first zone by the dividing means, thereby permitting substantial separation of the slag formed in the reaction between the molten metal and the desulfurizing agent from the molten metal before the molten metal is carried by the conveying trough.
Claim 19
Dependent Claim
13 words
A method according to claim 1 in which the molten metal is iron.
References Cited (Backward Citations)
US3467167A
Cited
US3734720A
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 |