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US4513089A
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Superrefractory dry ramming material based on zirconium oxide for the lining of induction-type crucible furnaces
Assignee: Dynamit Nobel AG
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Filing: 1983-10-25
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Granted: 1985-04-23
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Expires: 2003-10-25
Abstract
Abstract A superrefractory dry ramming material based on zirconium oxide for the lining of induction-type crucible furnaces comprising a zirconium oxide low in SiO2 and conventionally stabilized with CaO, MgO, Y2O3, rare earths or their mixed oxides which has a particle size ranging from 0 to 8 mm, and from 5 to 40 weight percent finely divided monoclinic, fused zirconium oxide containing less than 0.5 weight percent SiO2.
Inventors
- 👤 Peter Kummer
- 👤 Gerhard Rehfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:02
CPC Classifications
F; F27; F27B; F27B14/00; F27B14/08; F27B14/10; C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/482; C04B35/66; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3231; C04B2235/3244
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
88 words
A superrefractory dry ramming material based on zirconium oxide for the lining of induction-type crucible furnaces consisting essentially of a zirconium oxide low in SiO 2 and conventionally stabilized with CaO, MgO, Y 2 O 3 , rare earths or their mixed oxides which has a particle size ranging up to 8 mm, and from 5 to 40 weight percent finely divided monoclinic, fused zirconium oxide containing less than 0.5 eight percent SiO 2 the superrefractory material having a rammed density of at least 4.3 g/cm 3 .
Claim 2
Dependent Claim
88 words
A superrefractory dry ramming material based on zirconium oxide for the lining of induction-type crucible furnaces consisting essentially of a zirconium oxide low in SiO 2 and conventionally stabilized with CaO, MgO, Y 2 O 3 , rare earths or their mixed oxides which has a particle size ranging up to 8 mm, and from 5 to 40 weight percent finely divided monoclinic, fused zirconium oxide containing less than 0.5 eight percent SiO 2 the superrefractory material having a rammed density of at least 4.3 g/cm 3 .
Claim 3
Dependent Claim
14 words
Superrefractory material of claim 1 wherein said particle size ranges up to 4 mm.
Claim 4
Dependent Claim
20 words
Superrefractory material of claim 1 wherein said weight percent of the monoclinic fused zirconium oxide ranges from 10 to 20.
Claim 5
Dependent Claim
15 words
Superrefractory material of claim 1 wherein said weight percent SiO 2 ranges up to 0.2.
Claim 6
Dependent Claim
25 words
Superrefractory material of claim 1, wherein the chief component is a fully stabilized zirconium oxide containing from 3.7 to 5 weight percent CaO and/or MgO.
Claim 7
Dependent Claim
32 words
Superrefractory material of claim 5, wherein the monoclinic, fused zirconium oxide has a particle size ranging from 0 to 0.06 mm and an SiO 2 content of 0.2 weight percent or less.
Claim 8
Dependent Claim
80 words
The superrefractory material of claim 1 having a rammed density of at least 4.3 g/cm 3 and being composed of the following particle-size fractions: 0 to 0.07 mm--15 to 30 wt. % 0.07 to 0.12 mm--5 to 15 wt. % 0.12 to 0.25 mm--5 to 15 wt. % 0.25 to 0.5 mm--5 to 15 wt. % 0.5 to 1.0 mm--5 to 15 wt. % 1.0 to 2.0 mm--5 to 15 wt. % 2.0 to 4.0 mm--15 to 30 wt. %.
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) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |