Patent US1587707A successfully refreshed from Google Patents.
Patent US3942990A successfully refreshed from Google Patents.
US3942990A
Expired / Lapsed
US
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Method for producing foamed ceramics
Assignee: Euroc Administration AB
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Filing: 1973-07-09
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Granted: 1976-03-09
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Expires: 1993-07-09
Abstract
Abstract A method for the manufacture of foamed ceramics from a starting composition containing at least one component, which, when heated, forms a viscous, sintered and porous mass and a relatively difficultly oxidizable pore-forming agent for producing the porous structure, characterized by using as the starting composition a composition containing (1) at least one waste product rich in silica and containing readily oxidizable substances which, when heated, are themselves capable of producing uncontrollable pore formation and/or an undesirable melt, and (2) a strongly oxidizing agent, the quantity of oxidizing agent being such that the oxidizable substances are oxidized to eliminate or to reduce the uncontrollable pore formation and/or the melting and wherein the desired pore structure is obtained by oxidation of the difficultly oxidizable carbonaceous pore-forming agent.
Inventors
- 👤 Carl Bengt Alfred Engstrom
- 👤 Hans Georg Klang
- 👤 Gosta Persson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:13
CPC Classifications
C; C03; C03C; C03C11/00; C03C11/007; C03C1/00; C03C1/002; C04; C04B; C04B18/00; C04B18/04; C04B18/14; C04B28/00; C04B28/02; C04B38/00; C04B38/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
174 words
A method for the manufacture of foamed ceramics comprising 60 - 75% silica from a starting composition capable of forming, when heated, a viscous, sintered and porous mass, said starting composition comprising a. at least one silica-containing material selected from the group consisting of: fly ash obtained from waste-heat boilers, dust removed from waste gases emanating from electrometallurgical processes, and dust trapped in stone crushing plants, and sand and b. a product containing both ferrous compounds and readily carboniferous substances, said compounds and substances being capable of impairing pore formation, which method comprises mixing with the starting composition I. silicon carbide, and Ii. a strongly oxidizing agent selected from the group consisting of MnO 2 ,NaNO 3 and KMnO 4 capable of oxidizing the ferrous compounds into ferric compounds and the carbon of the readily oxidizable carboniferous compounds and the carbon of the SiC into gaseous compounds under the heating process, gaseous compounds from the SiC being formed after the composition has begun to melt, thereby to cause the pore formation to take place.
Claim 2
Independent Claim
174 words
A method for the manufacture of foamed ceramics comprising 60 - 75% silica from a starting composition capable of forming, when heated, a viscous, sintered and porous mass, said starting composition comprising a. at least one silica-containing material selected from the group consisting of: fly ash obtained from waste-heat boilers, dust removed from waste gases emanating from electrometallurgical processes, and dust trapped in stone crushing plants, and sand and b. a product containing both ferrous compounds and readily carboniferous substances, said compounds and substances being capable of impairing pore formation, which method comprises mixing with the starting composition I. silicon carbide, and Ii. a strongly oxidizing agent selected from the group consisting of MnO 2 ,NaNO 3 and KMnO 4 capable of oxidizing the ferrous compounds into ferric compounds and the carbon of the readily oxidizable carboniferous compounds and the carbon of the SiC into gaseous compounds under the heating process, gaseous compounds from the SiC being formed after the composition has begun to melt, thereby to cause the pore formation to take place.
Claim 3
Dependent Claim
45 words
A method according to claim 1 wherein said waste product rich in silica is selected from the group consisting of a. fly ash obtained from waste-heat boilers, b. dust removed from waste gases emanating from electrometallurgical processes, and c. dust trapped in stone crushing plants.
Claim 4
Dependent Claim
23 words
A method according to claim 1, wherein said starting composition contains from between approximately 25% and approximately 80% waste product rich in silica.
Claim 5
Dependent Claim
17 words
A method according to claim 1 wherein the starting composition contains alkali hydroxide as a fluxing agent.
Claim 6
Dependent Claim
37 words
A method according to claim 4 wherein the alkali hydroxide content of the starting composition is 8 - 12% calculated as R 2 O on the weight of the finished product, R designating an alkali metal atom.
Claim 7
Dependent Claim
40 words
A method according to claim 1 wherein the starting composition is admixed with a hydraulic binding agent or a latent hydraulic binding agent, and wherein the obtained mixture, subsequent to solidifying, is crushed into smaller pieces, which are then heated.
Claim 8
Dependent Claim
26 words
A method according to claim 1 wherein the starting composition is prepared in the form of an aqueous mixture and that said mixture is spray dried.
Claim 9
Dependent Claim
36 words
A method according to claim 1 wherein the starting composition or the waste product rich in silica is subjected to a roasting process with air to reduce the content of oxidizable substances to a lower level.
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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) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |