Patent US3729320A successfully refreshed from Google Patents.
Patent US4460528A successfully refreshed from Google Patents.
US4460528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractory
Assignee: Dresser Industries Inc
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Filing: 1981-05-12
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Granted: 1984-07-17
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Expires: 2001-05-12
Abstract
Abstract A means for producing nitride bonded refractory shapes, in situ, by mixing an aluminum metal powder, relatively pure silica, crude clay and a refractory aggregate. The mixes are pressed into shapes and burned at elevated temperatures in a nitriding atmosphere to form the bond.
Inventors
- 👤 Daniel R. Petrak
- 👤 Howard M. Winkelbauer
- 👤 Thomas R. Kleeb
- 👤 Ke-Chin Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:42
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/65
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
91 words
A method for producing nitride bonded refratory shapes, in situ, comprising mixing, a composition consisting essentially of, by weight, from about 1 to 25% aluminum, about 1 to 15% substantially pure silica, about 1 to 5% crude clay and the balance a refractory brickmaking size graded refractory aggregate selected from the group consisting of calcined fireclay, fused mullite, synthetic alumina and magnesium aluminate spinel, pressing said mixes into refractory shapes, and burning the shapes at an elevated temperature in a nitriding atmosphere for a time sufficient to form the nitride bond.
Claim 2
Independent Claim
91 words
A method for producing nitride bonded refratory shapes, in situ, comprising mixing, a composition consisting essentially of, by weight, from about 1 to 25% aluminum, about 1 to 15% substantially pure silica, about 1 to 5% crude clay and the balance a refractory brickmaking size graded refractory aggregate selected from the group consisting of calcined fireclay, fused mullite, synthetic alumina and magnesium aluminate spinel, pressing said mixes into refractory shapes, and burning the shapes at an elevated temperature in a nitriding atmosphere for a time sufficient to form the nitride bond.
Claim 3
Dependent Claim
39 words
Method of claim 1 in which the aluminum comprises, by weight, 3 to 13%, the substantially pure silica comprises, by weight, about 4 to 13%, and the crude clay comprises, by weight, about 1 to 2% of the mix.
Claim 4
Dependent Claim
19 words
Method of claim 1 in which the shapes are burned at a temperature between about 1090° and 1750° C.
Claim 5
Dependent Claim
24 words
Method of claim 1 in which the nitriding atmosphere is selected from the group consisting of gaseous nitrogen, industrial annealing gas and ammonia gas.
References Cited (Backward Citations)
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Cited
US3991166A
Cited
US3991148A
Cited
US4113503A
Cited
US4243621A
Cited
US4184884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |