US4533646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitride bonded oxide refractories
Assignee: Indresco Inc
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Filing: 1984-05-24
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Granted: 1985-08-06
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Expires: 2004-05-24
Abstract
Abstract This invention relates to a method for producing nitride bonded refractory shapes in which the bonding matrix is formed in situ. The method comprises forming a batch including a coarser portion selected from the group calcined and fused aggregates of alumina, aluminosilicate, and magnesium aluminate spinel and a finer portion consisting essentially of finely divided silicon metal and alumina as well as fines of the above mentioned refractory aggregate needed to achieve the desired screen analysis. The silicon metal and alumina react in the nitriding atmosphere to form a low porosity matrix generally comprising silicon oxynitride with corundum distributed therethrough.
Inventors
- 👤 Ke-Chin Wang
- 👤 Howard M. Winkelbauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:48
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/65; C04B35/01; C04B35/10; C04B35/101; C04B35/44; C04B35/66
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
115 words
A nitride bonded refractory shape formed by an in situ reaction in a nitriding atmosphere consisting essentially of a size graded batch comprising 55 to 63 percent, by weight, -3 to +65 mesh Tyler coarse refractory aggregate, selected from the group consisting of calcined and fused aggregates of alumina, alumino-silicate, and magnesium aluminate spinel, and 37 to 45 percent, by weight, of a -65 mesh Tyler, fine portion consisting essentially of 3 to 20 percent, by weight, silicon metal, 0.75 to 20 percent, by weight, alumina, and the balance consisting of fines of the refractory aggregate, the weight ratio of said -65 mesh Tyler alumina to said -65 mesh Tyler silicon, equaling at least 1:4.
Claim 2
Dependent Claim
115 words
A nitride bonded refractory shape formed by an in situ reaction in a nitriding atmosphere consisting essentially of a size graded batch comprising 55 to 63 percent, by weight, -3 to +65 mesh Tyler coarse refractory aggregate, selected from the group consisting of calcined and fused aggregates of alumina, alumino-silicate, and magnesium aluminate spinel, and 37 to 45 percent, by weight, of a -65 mesh Tyler, fine portion consisting essentially of 3 to 20 percent, by weight, silicon metal, 0.75 to 20 percent, by weight, alumina, and the balance consisting of fines of the refractory aggregate, the weight ratio of said -65 mesh Tyler alumina to said -65 mesh Tyler silicon, equaling at least 1:4.
Claim 3
Dependent Claim
19 words
The shape of claim 1 wherein the refractory aggregate is substantially free of iron oxide, chrome oxide and lime.
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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) | 1988-08-05 | 1989-02-04 | 1989-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-05 | 1993-02-04 | 1993-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-05 | 1997-02-04 | 1997-08-06 | $7700.00 | Window Closed / Lapsed |