US4042361A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of densifying metal oxides
Assignee: Corning Glass Works
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Filing: 1976-04-26
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Granted: 1977-08-16
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Expires: 1996-04-26
Abstract
Abstract A method of densifying a fumed metal oxide is disclosed wherein the metal oxide is converted to a flowable sol and then dried to form a fragmented solid which is calcined. The calcined oxide may be wet milled to provide a slip for casting articles such as fused silica crucibles used in melting silicon.
Inventors
- 👤 Peter P. Bihuniak
- 👤 Lewis H. Brandes
- 👤 Donald L. Guile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:31
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/10; C03B19/1005; C03B19/106; C03B19/1065; C03B19/06; C04; C04B; C04B35/00; C04B35/01; C04B35/14; Y; Y10; Y10S; Y10S65/00; Y10S65/901
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
121 words
A method of producing a fused silica glass article from fumed silica which comprises, a. mixing fumed silica with a polar liquid to form a flowable silica sol containing up to 45% solids content, b. removing the liquid from the sol to produce a fragmented solid, c. calcining the fragmented solid within the temperature range of 1150° C. to 1500° C. to densify the fragments, d. milling the densified particles with a casting medium to form a casting slip wherein the particles are essentially in the range of one to ten microns, e. casting the slip in a mold to form a "cast" body, and firing said cast body at a temperature on the order of 1800° C. to 1900° C.
Claim 2
Independent Claim
121 words
A method of producing a fused silica glass article from fumed silica which comprises, a. mixing fumed silica with a polar liquid to form a flowable silica sol containing up to 45% solids content, b. removing the liquid from the sol to produce a fragmented solid, c. calcining the fragmented solid within the temperature range of 1150° C. to 1500° C. to densify the fragments, d. milling the densified particles with a casting medium to form a casting slip wherein the particles are essentially in the range of one to ten microns, e. casting the slip in a mold to form a "cast" body, and firing said cast body at a temperature on the order of 1800° C. to 1900° C.
Claim 3
Dependent Claim
27 words
A method according to claim 1 wherein the silica sol is dried while being maintained in a form having a cross section not over one quarter inch.
Claim 4
Dependent Claim
21 words
A method according to claim 2 wherein the silica sol is maintained in a thin layer on a heated flat surface.
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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) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |