US3635740A
Expired / Lapsed
US
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Basic refractory shapes
Assignee: Dresser Industries Inc
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Filing: 1970-04-01
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Granted: 1972-01-18
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Expires: 1990-04-01
Abstract
Abstract Fired basic refractory shapes made from refractory brickmaking size-graded batches consisting of magnesite and chrome ore, the improvement being the inclusion of fireclay in the batch in amounts up to about 5 percent, by weight, and the two stage burning of resulting shapes to obtain high hot strength.
Inventors
- 👤 Ben Davies
- 👤 George R Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:12
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/42; C04B35/12; C04B35/44
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
25 words
Method according to claim 1 in which the total SiO2 contributed by the magnesite and chrome ore is less than about 5 percent by weight.
Claim 2
Dependent Claim
14 words
Method according to claim 1 in which the siliceous fireclay is a ball clay.
Claim 3
Dependent Claim
75 words
A fired, basic refractory shape consisting essentially of chrome ore and magnesia, said shape having a modulus of rupture at 2,700* F. of at least about 1,000 p.s.i., said shape made from a batch consisting of 50 to 80 percent, by weight, magnesite and 20 to 50 percent, by weight, chrome ore, and siliceous fireclay in amounts from about 0.5 percent to about 5 percent, based on the total weight of magnesite and chrome ore.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |