US4435510A
Expired / Lapsed
US
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Protection of graphite electrodes
Assignee: Foseco International Ltd
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Filing: 1982-08-03
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Granted: 1984-03-06
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Expires: 2002-08-03
Abstract
Abstract Matter for protecting graphite electrodes of electric arc furnaces, e.g. for steelmaking, to reduce loss of graphite by oxidation, comprises particles containing both a graphite-wetting fusible matrix material and a refractory filler. Methods of making and using the particulate matter are disclosed.
Inventors
- 👤 Dennis Greensmith
- 👤 Roderic H. Hammerton
- 👤 Colin J. Wall
- 👤 Dietger Dunkelmann
- 👤 Helmut Jaunich
- 👤 Josef Schiffarth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:24
CPC Classifications
B; B05; B05B; B05B13/00; B05B13/02; B05B13/0207; B05B13/0214; B05B7/00; B05B7/16; B05B7/22; C; C04; C04B; C04B41/00; C04B41/45; C04B41/50; C04B41/5025; C04B41/80; C04B41/81; C04B41/85; C04B41/87; H; H05; H05B; H05B7/00; H05B7/02; H05B7/06; H05B7/08; H05B7/085; H05B7/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
107 words
Particulate matter for the protection of a graphite 0.1 of an electric arc furnace to reduce loss of graphite by oxidation from the side of the electrode, said matter comprising particles each containing both a graphite-wetting fusible matrix material having a melting point below 1000° C. and a refractory filler, said particles comprising 30 to 80% by weight of refractory filler and 20 to 70% by weight of graphite-wetting fusible matrix material, the maximum particle size of the particles of the particulate matter being 0.5 mm and not more than 10% by weight of the matter comprising particles having a particle size of 0.1 mm or less.
Claim 2
Dependent Claim
107 words
Particulate matter for the protection of a graphite 0.1 of an electric arc furnace to reduce loss of graphite by oxidation from the side of the electrode, said matter comprising particles each containing both a graphite-wetting fusible matrix material having a melting point below 1000° C. and a refractory filler, said particles comprising 30 to 80% by weight of refractory filler and 20 to 70% by weight of graphite-wetting fusible matrix material, the maximum particle size of the particles of the particulate matter being 0.5 mm and not more than 10% by weight of the matter comprising particles having a particle size of 0.1 mm or less.
Claim 3
Dependent Claim
26 words
Particulate matter according to claim 1 comprising at least 70% by weight of particles each containing both a graphite-wetting fusible matrix material and a refractory filler.
Claim 4
Dependent Claim
26 words
Particulate matter according to claim 1 comprising at least 90% by weight of particles each containing both a graphite-wetting fusible matrix material and a refractory filler.
Claim 5
Dependent Claim
16 words
Particulate matter according to claim 1 wherein the graphite-wetting fusible matrix material is a boron compound.
Claim 6
Dependent Claim
16 words
Particulate matter according to claim 1 in which the graphite-wetting matrix material is a boron-containing glass.
Claim 7
Dependent Claim
27 words
Particulate matter according to claim 1 wherein the refractory filler is selected from the group consisting of refractory metals, refractory oxides, aluminosilicates, carbides, nitrides, silicides and borides.
Claim 8
Dependent Claim
16 words
Particulate matter according to claim 1 wherein the minimum size of the particles is 0.125 mm.
Claim 9
Dependent Claim
131 words
A process for the production of particulate matter for the protection of a graphite electrode of an arc furnace which comprises heating a mixture of a graphite-wetting fusible matrix material and a refractory filler to fuse said graphite-wetting material at least partially and to cause it to adhere to said refractory filler to form a coherent mass and then crushing the said coherent mass and sieving it to obtain the desired particle size, the resulting particles comprising 30 to 80% by weight of refractory filler and 20 to 70% by weight of graphite-wetting fusible matrix material, the maximum particle size of the particles of the particulate matter being 0.5 mm and not more than 10% by weight of the matter comprising particles having a particle size of 0.1 mm or less.
Claim 10
Dependent Claim
131 words
A process for the production of particulate matter for the protection of a graphite electrode of an arc furnace which comprises heating a mixture of a graphite-wetting fusible matrix material and a refractory filler to fuse said graphite-wetting material at least partially and to cause it to adhere to said refractory filler to form a coherent mass and then crushing the said coherent mass and sieving it to obtain the desired particle size, the resulting particles comprising 30 to 80% by weight of refractory filler and 20 to 70% by weight of graphite-wetting fusible matrix material, the maximum particle size of the particles of the particulate matter being 0.5 mm and not more than 10% by weight of the matter comprising particles having a particle size of 0.1 mm or less.
Claim 11
Dependent Claim
101 words
A process for the production of particulate matter for the protection of a graphite electrode of an arc furnace which comprises passing a mixture of a graphite-wetting fusible matrix material and a refractory filler through a heated zone where the said graphite-wetting material fuses at least partially and adheres to the said refractory filler to form agglomerated particles and passing the said agglomerated particles into a cooler zone to solidify the said graphite-wetting material whereby the said agglomerated particles do not adhere to each other and if necessary crushing the agglomerated particles and sieving them to give the desired particle size.
Claim 12
Dependent Claim
101 words
A process for the production of particulate matter for the protection of a graphite electrode of an arc furnace which comprises passing a mixture of a graphite-wetting fusible matrix material and a refractory filler through a heated zone where the said graphite-wetting material fuses at least partially and adheres to the said refractory filler to form agglomerated particles and passing the said agglomerated particles into a cooler zone to solidify the said graphite-wetting material whereby the said agglomerated particles do not adhere to each other and if necessary crushing the agglomerated particles and sieving them to give the desired particle size.
Claim 13
Independent Claim
87 words
A method of protecting a graphite electrode of an electric arc furnace to reduce loss of graphite by oxidation from the side of the electrode comprising contacting the side of the electrode with particulate matter comprising particles containing both a graphite-wetting fusible matrix material and a refractory filler whilst the electrode is at an elevated temperature such that said matrix material fuses at least partially and a protective coating comprising said refractory filler in a matrix of said matrix material is formed on the side of electrode.
Claim 14
Independent Claim
87 words
A method of protecting a graphite electrode of an electric arc furnace to reduce loss of graphite by oxidation from the side of the electrode comprising contacting the side of the electrode with particulate matter comprising particles containing both a graphite-wetting fusible matrix material and a refractory filler whilst the electrode is at an elevated temperature such that said matrix material fuses at least partially and a protective coating comprising said refractory filler in a matrix of said matrix material is formed on the side of electrode.
Claim 15
Dependent Claim
89 words
A process for the production of particulate matter for the protection of a graphite electrode of an arc furnace which comprises heating a mixture of a graphite-wetting fusible matrix material and a refractory filler to fuse said graphite-wetting material at least partially and to cause it to adhere to said refractory filler to form a coherent mass and then crushing the said coherent mass and sieving it to obtain the desired particle size, the heating being effected by pressing the mixture by use of at least one heated roller.
Claim 16
Dependent Claim
89 words
A process for the production of particulate matter for the protection of a graphite electrode of an arc furnace which comprises heating a mixture of a graphite-wetting fusible matrix material and a refractory filler to fuse said graphite-wetting material at least partially and to cause it to adhere to said refractory filler to form a coherent mass and then crushing the said coherent mass and sieving it to obtain the desired particle size, the heating being effected by pressing the mixture by use of at least one heated roller.
References Cited (Backward Citations)
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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) | 1987-03-06 | 1987-09-05 | 1988-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-06 | 1991-09-05 | 1992-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-06 | 1995-09-05 | 1996-03-06 | $7700.00 | Window Closed / Lapsed |