US3885956A
Expired / Lapsed
US
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Method and composition for the treatment of ferrous melts and process for making the treating composition
Assignee: Rheinische Kalksteinwerke GmbH
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Filing: 1974-05-21
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Granted: 1975-05-27
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Expires: 1994-05-21
Abstract
Abstract A composition for the desulfurization of a ferrous melt comprises particles of calcium carbide coated with metallic magnesium to protect them against moisture-laden air. The coated particles can be blown by a lance into the melt.
Inventors
- 👤 Karl-Heinz Obst
- 👤 Jurgen Stradtmann
- 👤 Paul Metz
- 👤 Francis Meyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:39
CPC Classifications
C; C21; C21C; C21C1/00; C21C1/02; C21C1/025; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
47 words
A METHOD OF DESULFURIZING A FERROUS MELT COMPRISING THE STEPS OF INTRODUCING INTO SAID MELT PARTICLES OF A SIZE BETWEEN 0.3 AND 5MM AND HAVING A CORE OF CALCIUM CARBIDE COATED WITH A METAL SHEATH OF MAGNESIUM CONSTITUTING 5 TO 25 PERCENT BY WEIGHT OF THE PARTICLES.
Claim 2
Independent Claim
47 words
A METHOD OF DESULFURIZING A FERROUS MELT COMPRISING THE STEPS OF INTRODUCING INTO SAID MELT PARTICLES OF A SIZE BETWEEN 0.3 AND 5MM AND HAVING A CORE OF CALCIUM CARBIDE COATED WITH A METAL SHEATH OF MAGNESIUM CONSTITUTING 5 TO 25 PERCENT BY WEIGHT OF THE PARTICLES.
Claim 3
Dependent Claim
26 words
The method defined in claim 1 wherein said particles are charged into said melt in an amount ranging between 0.05 and 0.5 percent by weight thereof.
Claim 4
Dependent Claim
23 words
The method defined in claim 2 wherein said particles are entrained into said melt close to the bottom thereof in a gas stream.
Claim 5
Dependent Claim
40 words
A desulfurizing agent consisting of a mass of calcium carbide particles individually coated with a metal sheath of magnesium constituting 5 to 25 percent by weight of said particles, said particles having a particle size between 0.3 and 5 mm.
Claim 6
Dependent Claim
40 words
A desulfurizing agent consisting of a mass of calcium carbide particles individually coated with a metal sheath of magnesium constituting 5 to 25 percent by weight of said particles, said particles having a particle size between 0.3 and 5 mm.
Claim 7
Dependent Claim
27 words
The desulfurizing agent defined in claim 4 wherein said calcium carbide contains a soluble or chemically nonreactive inorganic substance incorporated therewith in the cores of said particles.
Claim 8
Independent Claim
58 words
A method of making a desulfurizing agent for a ferrous melt comprising the steps of smelting a calcium oxide/magnesium oxide mixture and carbon in an electro-smelting calcium-carbide-producing furnace to form magnesium vapor and calcium carbide; granulating calcium carbide as produced in said furnace; and coating the granules of calcium carbide thus produced with magnesium condensed from said vapor.
Claim 9
Independent Claim
58 words
A method of making a desulfurizing agent for a ferrous melt comprising the steps of smelting a calcium oxide/magnesium oxide mixture and carbon in an electro-smelting calcium-carbide-producing furnace to form magnesium vapor and calcium carbide; granulating calcium carbide as produced in said furnace; and coating the granules of calcium carbide thus produced with magnesium condensed from said vapor.
Claim 10
Dependent Claim
19 words
The method defined in claim 6 wherein said magnesium oxide is formed at least in part by burned dolomite.
Claim 11
Dependent Claim
18 words
The method defined in claim 6 wherein said mixture is in part by dolomite- or magnesite-enriched burned lime.
Claim 12
Dependent Claim
47 words
The method defined in claim 6 wherein an excess of magnesium vapor is produced by said furnace beyond that which is required to coat granules of calcium carbide produced from said furnace, the excess magnesium vapor being used to coat calcium carbide granules derived from another source.
Claim 13
Dependent Claim
35 words
The method defined in claim 6, further comprising the step of entraining the particles coated with magnesium into a ferrous melt by a gas stream through a lance reaching to the bottom of the melt.
References Cited (Backward Citations)
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US2863755A
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US3467167A
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US3575695A
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US3622302A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |