US4912068A
Expired / Lapsed
US
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Magnesite-carbon refractories
Assignee: Resco Products Inc
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Filing: 1988-11-21
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Granted: 1990-03-27
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Expires: 2008-11-21
Abstract
Abstract A mix for forming a carbon-bonded refractory shape comprising from about 70 to 92 wt. % of a high purity magnesite and about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbon-containing bonding agent; said graphite containing at least about 98% carbon and having at least about 75% by weight -65 mesh or finer particles and said magnesite containing at least about 98% MgO, and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO2 weight ratio above about 2, and the resultant carbon-bonded refractory shape and liner for basic oxygen furnaces made from such shapes and the method of increasing the life of liners for basic oxygen furnaces.
Inventors
- 👤 David J. Michael
- 👤 David A. Kirk
- 👤 Leigh F. Brooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:47
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/01; C04B35/013; C04B35/03; C04B35/04; C04B35/043; C04B35/63448; C04B35/63472; C04B35/63496; C04B35/66; C04B2111/00; C04B2111/00474; C04B2111/0087; C04B2111/00887; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3206; C04B2235/42; C04B2235/422; C04B2235/70; C04B2235/96; C04B2235/9669; C04B2235/9676
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
114 words
A metal-free mix for forming a magnesite-carbon refractory shape comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 2
Dependent Claim
114 words
A metal-free mix for forming a magnesite-carbon refractory shape comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 3
Dependent Claim
30 words
The mix of claim 1 wherein said magnesite contains at least 99% MgO and said carbonaceous bonding agent is a novolak resin, a resol resin, tar, pitch, or mixtures thereof.
Claim 4
Dependent Claim
18 words
The mix of claim 1 or 2 wherein said graphite is a flake graphite or a vein graphite.
Claim 5
Dependent Claim
130 words
A metal-free mix for forming a magnesite-carbon refractory consisting essentially of from about 70 to 92 wt. % of a high purity magnesite and about 8 to 30 wt. % of a high purity flake graphite or a vein graphite, and for each 100 wt. % of said magnesite and graphite from abut 1.5 to 6 wt. % of a carbonaceous bonding agent selected from novolak resins, resol resins, tar, pitch or mixtures thereof; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 6
Dependent Claim
130 words
A metal-free mix for forming a magnesite-carbon refractory consisting essentially of from about 70 to 92 wt. % of a high purity magnesite and about 8 to 30 wt. % of a high purity flake graphite or a vein graphite, and for each 100 wt. % of said magnesite and graphite from abut 1.5 to 6 wt. % of a carbonaceous bonding agent selected from novolak resins, resol resins, tar, pitch or mixtures thereof; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 7
Dependent Claim
116 words
A metal-free unburned magnesite-carbon refractory shape consisting of a baked mix comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 8
Dependent Claim
116 words
A metal-free unburned magnesite-carbon refractory shape consisting of a baked mix comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 9
Dependent Claim
20 words
The refractory shape of claim 5 wherein said shape is a brick and said magnesite contains at least 99% MgO.
Claim 10
Dependent Claim
17 words
The refractory shape of claim 5 wherein said graphite is a flake graphite or a vein graphite.
Claim 11
Dependent Claim
26 words
The refractory shape of claim 5, 6, or 7 wherein said carbonaceous bonding agent is a novolak resin, a resol resin, tar, pitch, or mixtures thereof.
Claim 12
Dependent Claim
123 words
A metal-free unburned refractory brick consisting essentially of a baked mix consisting essentially of from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity flake graphite or a vein graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 13
Dependent Claim
123 words
A metal-free unburned refractory brick consisting essentially of a baked mix consisting essentially of from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity flake graphite or a vein graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 14
Dependent Claim
23 words
The refractory brick of claim 8 wherein said carbonaceous bonding agent is a novolak resin, a resol resin, tar, pitch, or mixtures thereof.
Claim 15
Dependent Claim
141 words
A refractory brick lining for metal processing equipment wherein a principal mode of wear of the lining is by slag attack comprising a plurality of unburned magnesite-carbon brick, said brick consisting essentially of a baked mix comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 16
Dependent Claim
141 words
A refractory brick lining for metal processing equipment wherein a principal mode of wear of the lining is by slag attack comprising a plurality of unburned magnesite-carbon brick, said brick consisting essentially of a baked mix comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magnesite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss on ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 17
Dependent Claim
46 words
The refractory brick liner of claim 11 for use in a basic oxygen furnace wherein the magnesite contains at least about 99% MgO and the graphite is a flake graphite or a vein graphite having at least about 95% by weight -65 mesh or finer particles.
Claim 18
Dependent Claim
26 words
The refractory brick liner of claim 11 or 12 wherein said carbonaceous bonding agent is a novolak resin, a resol resin, tar, pitch, or mixtures thereof.
Claim 19
Independent Claim
157 words
The method of increasing the life of liners for metal processing equipment wherein a principal mode of wear of the lining is by slag attack comprising forming a lining in said equipment comprising a plurality of unburned magnesite-carbon brick and subsequently burning said brick; said unburned brick consisting essentially of baked mix comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magensite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss of ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 20
Independent Claim
157 words
The method of increasing the life of liners for metal processing equipment wherein a principal mode of wear of the lining is by slag attack comprising forming a lining in said equipment comprising a plurality of unburned magnesite-carbon brick and subsequently burning said brick; said unburned brick consisting essentially of baked mix comprising from about 70 to 92 wt. % of a high purity magnesite and, correspondingly, about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite from about 1.5 to 6 wt. % of a carbonaceous bonding agent; said magensite containing at least about 98% MgO and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO 2 weight ratio above about 2, and said graphite having a loss of ignition of at least about 98% and at least about 75% by weight -65 mesh or finer particles.
Claim 21
Dependent Claim
48 words
The method of claim 14 for increasing the life of a liner for a basic oxygen furnace wherein the magnesite contains at least about 99% MgO and the graphite is a flake graphite or vein graphite having at least about 95% by weight -65 mesh or finer particles.
Claim 22
Independent Claim
24 words
The method of claims 14 or 15 wherein said carbonaceous bonding agent is a novolak resin, a resol resin, tar, pitch, or mixtures thereof.
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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) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |