US4384046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing mullite ceramic fiber products
Assignee: Isolite Babcock Refractories Co Ltd
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Filing: 1981-11-13
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Granted: 1983-05-17
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Expires: 2001-11-13
Abstract
Abstract Mullite ceramic fiber produced by mixing an aluminosilicate fiber having less than 72 weight percent of Al 2 O 3 with high-alumina substances, such as polycrystalline high-alumina fibers having more than 72 weight percent of Al 2 O 3 , and heating of the mixture to about 1,300° to 1,450° C., results in a refractory material characterized by lower bulk density, a low degree of contraction, substantial maintenance of original fiber shape, and total or nearly total consumption of free silica, with corresponding reduction in silicic acid.
Inventors
- 👤 Kashiro Nakagami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:48
CPC Classifications
C; C04; C04B; C04B30/00; C04B30/02; C04B35/00; C04B35/622; C04B35/62227; C04B35/62231; C04B35/6224; C04B35/62245
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
162 words
A method of producing mullite ceramic fiber products comprising blending of nitreous aluminosilicate fiber having an Al 2 O 3 content of less than 72 weight percent and at least one compound of fine crystals selected from the group consisting of polycrystalline high-alumina low-silica ceramic fiber having an Al 2 O 3 content of more than 72 weight percent and which may consist of mullite crystals in an amount equal to the amount of its SiO 2 content, sol-state alumina, gel-state alumina, ultra-fine powdered alumina, and a material which produces fine crystals of alpha-Al 2 O 3 as a result of heating; such that the resulting mixture has a total Al 2 O 3 content of more than 72 percent by weight; and heating of the resulting mixture to a temperature of about 1300° C. to 1450° C. whereby mullite is present in the final product from about 80 to 96 weight percent and alpha-alumina is 0 to about 3 weight percent.
Claim 2
Independent Claim
162 words
A method of producing mullite ceramic fiber products comprising blending of nitreous aluminosilicate fiber having an Al 2 O 3 content of less than 72 weight percent and at least one compound of fine crystals selected from the group consisting of polycrystalline high-alumina low-silica ceramic fiber having an Al 2 O 3 content of more than 72 weight percent and which may consist of mullite crystals in an amount equal to the amount of its SiO 2 content, sol-state alumina, gel-state alumina, ultra-fine powdered alumina, and a material which produces fine crystals of alpha-Al 2 O 3 as a result of heating; such that the resulting mixture has a total Al 2 O 3 content of more than 72 percent by weight; and heating of the resulting mixture to a temperature of about 1300° C. to 1450° C. whereby mullite is present in the final product from about 80 to 96 weight percent and alpha-alumina is 0 to about 3 weight percent.
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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) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |