US3879210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fused-cast refractory
Assignee: Unifrax I LLC
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Filing: 1972-06-14
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Granted: 1975-04-22
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Expires: 1992-06-14
Abstract
Abstract An improved high alumina fused-cast refractory which has a composite structure of massive primary corundum bonded with a refractory aluminum borosilicate glass. Articles formed from this refractory demonstrate superior resistance to corrosive and erosive conditions encountered in high temperature applications as well as resistance to deformation and cracking. The preferred composition of the refractory comprises about 99 weight percent of alumina, with about 0.5 weight percent each of boric oxide and silica. Small amounts of other metallic oxides will adversely effect the properties of the refractory if they are present in amounts of more than 0.3 weight percent.
Inventors
- 👤 Richard Gary Labar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:57
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/107
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
56 words
A FUSED-CAST REFACTORY ARTICLE COMPRISING CRYSTALS OF CORUNDUM BONDED BY A REFACTORY ALUMINUM BOROSILICATE GLASS, AND ATICLE COMPRISING ABOUT 98 TO AOUT 99 WEIGHT PERCENT ALUMINA, ABOUT 00.3 TO ABOUT 0.7 WEIGHT PERCENT BORIC OXIDE AND ABOUT 0.4 TO ABOUT 0.9 WEIGHT PERCENT SILICA, THE RATIO OF BORIC OXIDE TO SILICA BEING FROM 0.4 TO 1.5.
Claim 2
Dependent Claim
56 words
A FUSED-CAST REFACTORY ARTICLE COMPRISING CRYSTALS OF CORUNDUM BONDED BY A REFACTORY ALUMINUM BOROSILICATE GLASS, AND ATICLE COMPRISING ABOUT 98 TO AOUT 99 WEIGHT PERCENT ALUMINA, ABOUT 00.3 TO ABOUT 0.7 WEIGHT PERCENT BORIC OXIDE AND ABOUT 0.4 TO ABOUT 0.9 WEIGHT PERCENT SILICA, THE RATIO OF BORIC OXIDE TO SILICA BEING FROM 0.4 TO 1.5.
Claim 3
Dependent Claim
56 words
A fused-cast refractory article comprising crystals of corundum bonded by a refractory aluminum borosilicate glass, said article comprising about 98 to about 99 weight percent alumina, about 0.3 to about 0.7 weight percent boric oxide and about 0.4 to about 0.9 weight percent silica, the ratio of boric oxide to silica being from 0.4 to 1.5.
Claim 4
Dependent Claim
56 words
A fused-cast refractory article comprising crystals of corundum bonded by a refractory aluminum borosilicate glass, said article comprising about 98 to about 99 weight percent alumina, about 0.3 to about 0.7 weight percent boric oxide and about 0.4 to about 0.9 weight percent silica, the ratio of boric oxide to silica being from 0.4 to 1.5.
Claim 5
Dependent Claim
25 words
A fused-cast refractory article according to claim 1 consisting essentially of 99 weight percent alumina, 0.5 weight percent boric oxide and 0.5 weight percent silica.
Claim 6
Dependent Claim
16 words
A fused-cast refractory article according to claim 1 in which the crystals of corundum are interlocking.
References Cited (Backward Citations)
US2695849A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |