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US4212679A
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Method of making magnesite grain
Assignee: Indresco Inc
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Filing: 1978-09-12
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Granted: 1980-07-15
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Expires: 1998-09-12
Abstract
Abstract A method of making magnesite grain having an MgO content between about 85 and 95% and consisting of periclase, calcium zirconate and dicalcium silicate.
Inventors
- 👤 Kermit M. Bonar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:29
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/03; C04B35/04; C04B35/043; C04B35/0435
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A method for making magnesite grain comprising mixing magnesium hydroxide slurry, lime yielding material and zircon in proportions sufficient to provide an MgO content between 85 and 95%, by weight, and calcining the mixture with subsequent dead burning to provide a grain consisting essentially of 2.5 to 7.7%, by weight, calcium zirconate, 2.4 to 7.4%, by weight, dicalcium silicate and the balance periclase.
Claim 2
Independent Claim
63 words
A method for making magnesite grain comprising mixing magnesium hydroxide slurry, lime yielding material and zircon in proportions sufficient to provide an MgO content between 85 and 95%, by weight, and calcining the mixture with subsequent dead burning to provide a grain consisting essentially of 2.5 to 7.7%, by weight, calcium zirconate, 2.4 to 7.4%, by weight, dicalcium silicate and the balance periclase.
Claim 3
Dependent Claim
24 words
Method according to claim 1 in which an amount up to 10% by weight, calcium zirconate and dicalcium silicate are present in the grain.
Claim 4
Dependent Claim
24 words
Method according to claim 1 in which the grain are characterized as having periclase crystallites surrounded by dicalcium silicate and finely crystalline calcium zirconate.
Claim 5
Dependent Claim
18 words
Method according to claim 1 in which the grain has a specific gravity of more than about 3.3.
Claim 6
Dependent Claim
25 words
A refractory grain comprising 85 to 95%, by weight, periclase, 2.5 to 7.7% by weight, calcium zirconate and 2.4 to 7.4%, by weight dicalcium silicate.
Claim 7
Dependent Claim
25 words
A refractory grain comprising 85 to 95%, by weight, periclase, 2.5 to 7.7% by weight, calcium zirconate and 2.4 to 7.4%, by weight dicalcium silicate.
Claim 8
Dependent Claim
25 words
A grain according to claim 5, in which an amount up to 10%, by weight, calcium zirconate and dicalcium silicate are present in the grain.
Claim 9
Dependent Claim
22 words
A grain according to claim 5 which is characterized as having periclase crystallites surrounded by dicalcium silicate and finely crystalline calcium zirconate.
Claim 10
Dependent Claim
16 words
A grain according to claim 5 which has a specific gravity of more than about 3.3.
References Cited (Backward Citations)
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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) | 1983-07-15 | 1984-01-14 | 1984-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-15 | 1988-01-14 | 1988-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-15 | 1992-01-14 | 1992-07-15 | $7700.00 | Window Closed / Lapsed |