US4348236A
Expired / Lapsed
US
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Composition for castable refractory block
Assignee: Alcoa Corp
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Filing: 1980-09-09
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Granted: 1982-09-07
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Expires: 2000-09-09
Abstract
Abstract A particulate refractory mixture is disclosed which is suitable for combination with water to form a castable refractory having high strength, low porosity and enhanced resistance to molten aluminum. The mixture consists essentially of 79.5-89.5% by weight alumina, 10-20% by weight calcium aluminate and 0.5-1.5% by weight borosilicate frit.
Inventors
- 👤 James E. Hines, Jr.
- 👤 Richard G. LaBar, deceased
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:48
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/101; C04B28/00; C04B28/02; C04B28/06; C04B2111/00; C04B2111/00474; C04B2111/0087; C04B2111/00879
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
43 words
A particulate refractory mixture suitable for combination with water to form a castable refractory having high strength, low porosity and enhanced resistance to molten aluminum, consisting essentially of: 79.5-89.5% by weight alumina; 10-20% by weight calcium aluminate; and 0.5-1.5% by weight borosilicate frit.
Claim 2
Dependent Claim
43 words
A particulate refractory mixture suitable for combination with water to form a castable refractory having high strength, low porosity and enhanced resistance to molten aluminum, consisting essentially of: 79.5-89.5% by weight alumina; 10-20% by weight calcium aluminate; and 0.5-1.5% by weight borosilicate frit.
Claim 3
Dependent Claim
51 words
The mixture of claim 1 wherein the particle size of the alumina is controlled such that: 20-40% by weight is less than 4.76 mm but greater than 1.41 mm; 15-30% by weight is less than 1.41 mm but greater than 0.297 mm; and 25-40% by weight is less than 0.297 mm.
Claim 4
Dependent Claim
13 words
The mixture of claim 1 wherein the calcium aluminateby weight of other oxides.
Claim 5
Dependent Claim
27 words
The mixture of claim 1 wherein the particle size of the calcium aluminate is controlled so that at least 90% by weight is less than 0.044 mm.
Claim 6
Dependent Claim
13 words
The mixture of claim 1 wherein the frit contains 5-25% by weight fluorine.
Claim 7
Dependent Claim
28 words
The mixture of claim 5 wherein the frit contains 15-35% by weight boron oxide, 5-30% by weight silicon dioxide and no more than 20% by weight alkali compounds.
Claim 8
Dependent Claim
19 words
The mixture of claim 6 wherein the particle size of the frit is controlled to less than 0.149 mm.
Claim 9
Dependent Claim
19 words
The mixture of claim 7 wherein the melting point of the frit is between 620° C. and 760° C.
Claim 10
Dependent Claim
42 words
A refractory composition suitable for mixture with water for casting into a large block, consisting essentially of: 80-85% by weight alumina; 14-18% by weight calcium aluminate; and 0.5-1.5% by weight of a borosilicate frit, wherein said frit contains 10-15% by weight fluorine.
Claim 11
Dependent Claim
42 words
A refractory composition suitable for mixture with water for casting into a large block, consisting essentially of: 80-85% by weight alumina; 14-18% by weight calcium aluminate; and 0.5-1.5% by weight of a borosilicate frit, wherein said frit contains 10-15% by weight fluorine.
Claim 12
Dependent Claim
49 words
The composition of claim 9 wherein the alumina particle size is controlled such that: 20-40% by weight is less than 4.76 mm but greater than 1.41 mm; 15-30% by weight is less than 1.41 mm but greater than 0.297 mm; and 25-40% by weight is less than 0.297 mm.
Claim 13
Dependent Claim
33 words
The composition of claim 9 wherein the calcium aluminate comprises a mixture of 75-83% by weight aluminum oxide, 14-23% by weight calcium oxide and no more than 3% by weight of other oxides.
Claim 14
Dependent Claim
27 words
The composition of claim 9 wherein the particle size of the calcium aluminate is controlled so that at least 90% by weight is less than 0.044 mm.
Claim 15
Dependent Claim
28 words
The composition of claim 9 wherein the frit contains 15-35% by weight boron oxide, 5-30% by weight silicon dioxide and no more than 20% by weight alkali compounds.
Claim 16
Dependent Claim
19 words
The composition of claim 13 wherein the particle size of the frit is controlled to less than 0.149 mm.
Claim 17
Dependent Claim
19 words
The composition of claim 14 wherein the melting point of the frit is between 620° C. and 760° C.
Claim 18
Independent Claim
155 words
A method for making a large block, comprising: (a) blending a dry composition consisting essentially of: 79.5-89.5% by weight alumina, 10-20% by weight calcium aluminate, and 0.5-1.5% by weight borosilicate frit; (b) mixing the blend with 5-8% by weight water; (c) casting the mixture in the form of a large block; (d) curing the block at 21°-32° C. for at least 8 hours; (e) drying the cured block to remove physically absorbed water; (f) heating the dried block, at a rate no greater than 20° C./hour, from drying temperature to a hold temperature within the range of 235°-320° C.; (g) maintaining the block at the hold temperature until the block is uniformly heated to that temperature; (h) heating the block, at a rate no greater than 30° C./hour, from the hold temperature to a firing temperature of at least 600° C.; and (i) maintaining the block at the firing temperature for at least 5 hours.
Claim 19
Independent Claim
155 words
A method for making a large block, comprising: (a) blending a dry composition consisting essentially of: 79.5-89.5% by weight alumina, 10-20% by weight calcium aluminate, and 0.5-1.5% by weight borosilicate frit; (b) mixing the blend with 5-8% by weight water; (c) casting the mixture in the form of a large block; (d) curing the block at 21°-32° C. for at least 8 hours; (e) drying the cured block to remove physically absorbed water; (f) heating the dried block, at a rate no greater than 20° C./hour, from drying temperature to a hold temperature within the range of 235°-320° C.; (g) maintaining the block at the hold temperature until the block is uniformly heated to that temperature; (h) heating the block, at a rate no greater than 30° C./hour, from the hold temperature to a firing temperature of at least 600° C.; and (i) maintaining the block at the firing temperature for at least 5 hours.
Claim 20
Dependent Claim
12 words
The method of claim 16 wherein the hold temperature is 260° C.
Claim 21
Dependent Claim
25 words
The method of claim 16 wherein the cured block is dried at a temperature within the range of 35°-110° C. for at least 24 hours.
Claim 22
Dependent Claim
49 words
The method of claim 16 wherein the alumina particle size is controlled such that: 20-40% by weight is less than 4.76 mm but greater than 1.41 mm; 15-30% by weight is less than 1.41 mm but greater than 0.297 mm; and 25-40% by weight is less than 0.297 mm.
Claim 23
Dependent Claim
33 words
The method of claim 16 wherein the calcium aluminate comprises a mixture of 75-83% by weight aluminum oxide, 14-23% by weight calcium oxide and no more than 3% by weight of other oxides.
Claim 24
Dependent Claim
27 words
The method of claim 16 wherein the particle size of the calcium aluminate is controlled so that at least 90% by weight is less than 0.044 mm.
Claim 25
Dependent Claim
28 words
The method of claim 16 wherein the frit contains 15-35% by weight boron oxide, 5-30% by weight silicon dioxide and no more than 20% by weight alkali compounds.
Claim 26
Dependent Claim
19 words
The method of claim 16 wherein the particle size of the frit is controlled to less than 0.149 mm.
Claim 27
Dependent Claim
19 words
The method of claim 16 wherein the melting point of the frit is between 620° C. and 760° C.
References Cited (Backward Citations)
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US3764354A
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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) | 1985-09-06 | 1986-03-08 | 1986-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-06 | 1990-03-08 | 1990-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-06 | 1994-03-08 | 1994-09-07 | $7700.00 | Window Closed / Lapsed |