US4780434A
Expired / Lapsed
US
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Refractory composition
Assignee: Coorstek KK
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Filing: 1986-12-22
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Granted: 1988-10-25
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Expires: 2006-12-22
Abstract
Abstract A refractory composition which is suitable for forming a sliding gate to be used at the bottom of a ladle or tundish is provided. The refractory composition comprises 10 to 30 parts by weight of an alumina-magnesia spinel material containing 40 to 70% by weight of Al 2 O 3 , 25 to 60% by weight of MgO and 10% or less of impurities, and 70 to 90 parts by weight of a magnesia material containing at least 90% by weight of MgO, wherein the composition contains 10 to 25% by weight of Al 2 O 3 and 75 to 90% by weight of MgO. 1 to 10 parts by weight of Al 2 O 3 material may be further added together with the alumina-magnesia spinel material and the magnesia material, to form the refractory composition.
Inventors
- 👤 Takashi Watanabe
- 👤 Takumi Nishio
- 👤 Yoshihisa Kato
- 👤 Kazuhide Kawai
- 👤 Satoshi Doro
- 👤 Takafumi Nishibe
- 👤 Takahiro Fukaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:39
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/08; C; C04; C04B; C04B35/00; C04B35/01; C04B35/03; C04B35/04; C04B35/043; B22D41/00; B22D41/14; B22D41/22; B22D41/28; B22D41/30; B22D41/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
157 words
A starting batch for a refractory material consisting essentially of: (a) from about 10 to 30 parts by weight of a primary alumina-magnesia spinel material consisting essentially of from about 40 to 75% by weight of Al 2 O 3 and from about 25 to 60% by weight of MgO; (b) from about 70 to 90 parts by weight of a magnesia material containing at least about 90% by weight of MgO; and (c) from about 1 to 10 parts by weight of an alumina material having an average particle size of less than about 10 microns, upon firing said alumina material forming, in a matrix portion between said primary spinel and said magnesia material, a secondary spinel structure with said magnesia material; wherein said starting batch results in a refractory material consisting essentially of from about 10 to 25% by weight of Al 2 O 3 and from about 75 to 90% by weight of MgO.
Claim 2
Dependent Claim
157 words
A starting batch for a refractory material consisting essentially of: (a) from about 10 to 30 parts by weight of a primary alumina-magnesia spinel material consisting essentially of from about 40 to 75% by weight of Al 2 O 3 and from about 25 to 60% by weight of MgO; (b) from about 70 to 90 parts by weight of a magnesia material containing at least about 90% by weight of MgO; and (c) from about 1 to 10 parts by weight of an alumina material having an average particle size of less than about 10 microns, upon firing said alumina material forming, in a matrix portion between said primary spinel and said magnesia material, a secondary spinel structure with said magnesia material; wherein said starting batch results in a refractory material consisting essentially of from about 10 to 25% by weight of Al 2 O 3 and from about 75 to 90% by weight of MgO.
Claim 3
Dependent Claim
36 words
A starting batch according to claim 1, wherein said refractory material consists essentially of from about 12 to 20% by weight of Al 2 O 3 and from about 80 to 88% by weight of MgO.
Claim 4
Dependent Claim
15 words
A starting batch according to claim 1, further consisting essentially of an additional refractory material.
Claim 5
Dependent Claim
21 words
A starting batch according to claim 3, wherein said additional refractory material consists essentially of chrome ore, chromium oxide or zirconia.
Claim 6
Dependent Claim
13 words
A starting batch according to claim 1, further consisting essentially of a metal.
Claim 7
Dependent Claim
18 words
A starting batch according to claim 5, wherein said metal consists essentially of Si, Al, Fe--Si or Mg.
Claim 8
Dependent Claim
38 words
A starting batch according to claim 1, wherein said refractory material is impregnated with tar, pitch, resin or a liquid material containing substances which can be converted into silica, alumina, magnesia, zirconia or chromium oxide upon heat treatment.
Claim 9
Dependent Claim
185 words
A process for producing a refractory material comprising the steps of: (a) mixing raw materials consisting essentially of from about 10 to 30 parts by weight of a primary alumina-magnesia spinel material comprising from about 40 to 75% by weight of Al 2 O 3 and from about 25 to 60% by weight of MgO, from about 70 to 90 parts by weight of a magnesia material containing at least about 90% by weight of MgO, and from about 1 to 10 parts by weight of a alumina material having an average particle size of less than about 10 microns to form a kneaded mixture; (b) molding said kneaded mixture to a desired form; (c) drying said molded form; and (d) firing said dried molded form under an oxidizing atmosphere, so as to form in a matrix portion of said refractory material between said primary spinel and said magnesia material, a secondary spinel structure with said magnesia material; wherein said refractory material comprises from about 10 to 25% by weight of Al 2 O 3 and from about 75 to 90% by weight of MgO.
Claim 10
Dependent Claim
185 words
A process for producing a refractory material comprising the steps of: (a) mixing raw materials consisting essentially of from about 10 to 30 parts by weight of a primary alumina-magnesia spinel material comprising from about 40 to 75% by weight of Al 2 O 3 and from about 25 to 60% by weight of MgO, from about 70 to 90 parts by weight of a magnesia material containing at least about 90% by weight of MgO, and from about 1 to 10 parts by weight of a alumina material having an average particle size of less than about 10 microns to form a kneaded mixture; (b) molding said kneaded mixture to a desired form; (c) drying said molded form; and (d) firing said dried molded form under an oxidizing atmosphere, so as to form in a matrix portion of said refractory material between said primary spinel and said magnesia material, a secondary spinel structure with said magnesia material; wherein said refractory material comprises from about 10 to 25% by weight of Al 2 O 3 and from about 75 to 90% by weight of MgO.
Claim 11
Dependent Claim
32 words
A process according to claim 8, wherein said refractory material consists essentially of from about 12-20% by weight of Al 2 O 3 and from 80 to 88% by weight of MgO.
References Cited (Backward Citations)
US3184322A
Cited
AU212021A
Cited
US2152656A
Cited
US2618566A
Cited
GB825908A
Cited
US3106475A
Cited
US3577247A
Cited
JPS4999306A
Cited
JPS5036249A
Cited
SU554251A1
Cited
US4126479A
Cited
DE2745461B1
Cited
JPS55149170A
Cited
JPS566391A
Cited
JPS5692160A
Cited
US4389492A
Cited
JPS58120568A
Cited
US4533646A
Cited
JPS5935068A
Cited
EP0113886A1
Cited
JPS59203769A
Cited
US4506022A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-25 | 1992-04-25 | 1992-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-25 | 1996-04-25 | 1996-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-25 | 2000-04-25 | 2000-10-25 | $7700.00 | Window Closed / Lapsed |