US4207114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foamed ceramic element and process for making same
Assignee: Schneider GmbH and Co KG
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Filing: 1978-05-26
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Granted: 1980-06-10
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Expires: 1998-05-26
Abstract
Abstract A foamed ceramic product and method for making same is disclosed. The foamed ceramic is characterized by a high compressive strength, high insulating properties and low fluid permeability when compared against conventional materials. This foamed ceramic is made by mixing a clay mineral with a foaming agent comprising a combination of sulfate and sulfide compounds, heating to a temperature of about 1,000° C. where controlled foaming occurs and then cooling the resulting foamed product. Additionally, there is disclosed a foamed ceramic product and method for making same which is characterized by its fire resistant properties as a result of creating micro cracks therein which permit controlled fluid permeability. This foamed ceramic product is made by controlling the phase constituents and heating and cooling temperatures to induce stresses which result in such micro cracks.
Inventors
- 👤 Peter Schuster
- 👤 Bernd VON Chiari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:41
CPC Classifications
C; C04; C04B; C04B38/00; C04B38/02; C04B33/00; C04B33/02; C04B33/13
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
97 words
Foamed ceramic element formed from clay-mineral raw materials comprising a body portion which includes a pore distribution having two maxima, the first maximum is formed by the average diameter of large pores, the second maximum is formed by the average diameter of the smaller pores, said smaller pores permeate the solid web between the large pores, said solid web further including microscopic cracks which partially interconnect the large and small pores thereby providing an open porosity, said foamed ceramic element having improved fire resistant characteristics and a water absorption characteristic of from about 10% to about 25%.
Claim 2
Dependent Claim
97 words
Foamed ceramic element formed from clay-mineral raw materials comprising a body portion which includes a pore distribution having two maxima, the first maximum is formed by the average diameter of large pores, the second maximum is formed by the average diameter of the smaller pores, said smaller pores permeate the solid web between the large pores, said solid web further including microscopic cracks which partially interconnect the large and small pores thereby providing an open porosity, said foamed ceramic element having improved fire resistant characteristics and a water absorption characteristic of from about 10% to about 25%.
Claim 3
Dependent Claim
35 words
The foamed ceramic element according to claim 1, wherein the proportion of the microscopic cracks is from 0.3 to 1.1% by volume which results in an open porosity of from 10 to 25% by volume.
Claim 4
Dependent Claim
27 words
The foamed ceramic element according to claim 1, wherein said solid web includes embedded crystals and/or crystallites of anorthite and crystobalite which are surrounded by microscopic cracks.
Claim 5
Dependent Claim
32 words
The foamed ceramic element according to claim 3, wherein the crystobalite component comprises from about 2 to about 20%, and the anorthite component comprises from about 2 to about 30% by weight.
Claim 6
Dependent Claim
32 words
The foamed ceramic element according to claim 3, wherein the crystobalite component comprises from about 5% to about 15%, and the anorthite component comprises from about 10% to about 25%, by weight.
Claim 7
Dependent Claim
19 words
The foamed ceramic element according to claim 1, characterized by a diffusion resistance factor of from 60 to 160.
Claim 8
Dependent Claim
30 words
The foamed ceramic element according to claim 1, wherein said microscopic cracks are from about 10 to about 30 μm long, and from about 0.1 to about 0.5 μm wide.
Claim 9
Dependent Claim
32 words
The foamed ceramic element according to claim 1, wherein said microscopic cracks are from about 16 μm to about 20 μm long and from about 0.2 μm to about 0.4 μm wide.
Claim 10
Dependent Claim
28 words
The foamed ceramic element according to claim 1, wherein said microscopic cracks are partially in communication with each other and partially extend to the large and/or small pores.
Claim 11
Dependent Claim
83 words
Method for the production of a foamed ceramic element according to claim 1 comprising the steps of: admixing at least one raw material, including a clay-mineral-containing raw material with a foaming adjuvant of sulfate and sulfide in a ratio of sulfate: sulfide of between about 10:1 to 1:1; drying said mixture; placing said dried mixture in mold forms; heating said mixture to foaming; and cooling under conditions which produce tensions in the webs which are then dissipated by the formation of microscopic cracks.
Claim 12
Dependent Claim
22 words
The method according to claim 10, wherein said foaming is performed with the assistance of an exothermic reaction of the foaming adjuvant.
Claim 13
Dependent Claim
23 words
The method according to claim 11, including the step of equalizing the temperature before swelling by means of a period of constant temperature.
Claim 14
Dependent Claim
29 words
The method according to claim 10, wherein said raw material includes one of the foaming adjuvant components, further including the step of admixing a second foaming adjuvant component thereto.
Claim 15
Dependent Claim
12 words
The method according to claim 10, wherein said raw material is swellable.
Claim 16
Dependent Claim
36 words
The method according to claim 10, wherein the microscopic cracks are produced by controlling the temperature during the cooling of the foamed product, said web including at least two phases having different coefficients of thermal expansion.
Claim 17
Dependent Claim
20 words
The method according to claim 15, wherein the mixture of two phases produced in the web are substantially homogeneously distributed.
Claim 18
Dependent Claim
37 words
The method according to claim 16, wherein the phase mixture is produced by crystalization from the melt phase during cooling, whereby the formed crystals and/or crystallites have a higher coefficient of thermal expansion than said melt phase.
Claim 19
Dependent Claim
13 words
The method according to claim 17, wherein anorthite and crystobalite crystals are produced.
Claim 20
Dependent Claim
18 words
The method according to claim 18, wherein said raw material is a stone clay with an illite component.
Claim 21
Dependent Claim
44 words
The method according to claim 19, wherein the cooling step is carried out at a rate of 2.0° to 5.0° C./min. until the phase transformation interval is reached, and below the transformation interval cooling proceeds at the rate of from 0.4° to 1.2° C./min.
Claim 22
Dependent Claim
16 words
The method according to claim 18, wherein the raw materials are prepared with a sand mill.
Claim 23
Dependent Claim
47 words
The method according to claim 15, wherein a homogeneous granulate mixture of at least two types of granulate material are foamed and cooled, each type of granulate material forming a melt and glass phase which has a different coefficient of thermal expansion from the other glass phase.
Claim 24
Dependent Claim
19 words
The method according to claim 22, wherein a raw granule type is mixed with a pre-swelled type of granulate.
Claim 25
Dependent Claim
27 words
The method according to claim 22, wherein a raw granulate material or pre-swelled type of granulate material is mixed with a foamed, ground type of granulate material.
Claim 26
Dependent Claim
43 words
The method according to claim 22, wherein a raw granulate material is produced out of raw materials, foaming adjuvants and ground, foamed ceramic product, by intimate mixing, whereby the grain for the second phase is homogeneously distributed and embedded in the granulate material.
Claim 27
Dependent Claim
22 words
The method according to claim 25, wherein the pre-foamed granulate material possesses a greater coefficient of thermal expansion than said melt phase.
Claim 28
Dependent Claim
61 words
The method according to claim 22, wherein one type of granulate material has a coefficient of thermal expansion after foaming in the range of from about 4.2 to 5.0×10 -6 °C. -1 is mixed with another type of granulate material having a coefficient of thermal expansion after foaming in the range of from about 5.0 to 7.0×10 -6 °C. -1 .
Claim 29
Dependent Claim
41 words
The method according to claim 27, wherein the cooling step is carried out at the rate of from 2.0° to 5.0° C./min. before the phase transformation interval is reached, and from 0.4° to 1.2° C./min. after the transformation interval is reached.
Claim 30
Dependent Claim
19 words
The method according to claim 10, wherein said web includes two glass phases and at least one crystal phase.
Claim 31
Dependent Claim
28 words
The method according to claim 15, wherein a granulate material mixture of at least two types of granulate material is used, whose glass phases have different transformation ranges.
Claim 32
Dependent Claim
19 words
The method according to claim 30, wherein the difference of the transformation intervals is from 5° to 25° C.
Claim 33
Dependent Claim
32 words
The method according to claim 30, wherein a granulate of the raw material matrix which includes ground quartz, is used to produce the glass phase with a higher coefficient of thermal expansion.
Claim 34
Dependent Claim
34 words
The method according to claim 30, wherein a granulate of the raw material matrix includes clay rich in fine quartz, is used to produce the glass phase with a higher coefficient of thermal expansion.
Claim 35
Dependent Claim
98 words
Process for the production of a foamed ceramic element from mineral raw materials not ordinarily capable of being swelled, including clay-mineral-containing raw materials, with or without fluxing agents, comprising the steps of admixing said mineral raw material with a sulfate and sulfide foaming adjuvant and water, drying the mixture to be foamed and then placing the dried mixture into molds prior to foaming, heating the mixture at about 1000° C. or more until foaming occurs, and subsequently cooling the foamed ceramic, and said foaming adjuvant is added in a ratio of sulfate:sulfide of between about 10:1 to 1:1.
Claim 36
Dependent Claim
98 words
Process for the production of a foamed ceramic element from mineral raw materials not ordinarily capable of being swelled, including clay-mineral-containing raw materials, with or without fluxing agents, comprising the steps of admixing said mineral raw material with a sulfate and sulfide foaming adjuvant and water, drying the mixture to be foamed and then placing the dried mixture into molds prior to foaming, heating the mixture at about 1000° C. or more until foaming occurs, and subsequently cooling the foamed ceramic, and said foaming adjuvant is added in a ratio of sulfate:sulfide of between about 10:1 to 1:1.
Claim 37
Dependent Claim
23 words
The process according to claim 34, wherein the foaming adjuvant of sulfate and sulfide is added in a ratio of sulfate:sulfide of 3:1.
Claim 38
Dependent Claim
35 words
The process according to claim 34, including the steps of adding the foaming adjuvants in relation to the solid substance in an amount ranging from about 0.2 to 10%, preferably 2 to 5% by weight.
Claim 39
Dependent Claim
23 words
The process according to claim 34, including the step of employing a combination of iron sulfate and iron sulfide as the foaming adjuvant.
Claim 40
Dependent Claim
22 words
The process according to claim 34, characterized by the fact that the foaming adjuvant added is at least partially soluble in water.
Claim 41
Dependent Claim
25 words
The process according to claim 34, characterized by the fact foaming adjuvant added is a composition which contains at least one of the sulfur compounds.
Claim 42
Dependent Claim
16 words
The process according to claim 39, wherein said foaming adjuvant comprises natural and industrial waste products.
Claim 43
Dependent Claim
16 words
The process according to claim 40, wherein said foaming adjuvant comprises particles below about 200 μm.
Claim 44
Dependent Claim
19 words
The process according to claim 34, wherein the foaming step is effected at between about 1,000° to 1,200° C.
Claim 45
Dependent Claim
19 words
The process according to claim 42, wherein the foaming step is carried out between about 10 to 180 minutes.
Claim 46
Dependent Claim
18 words
The process according to claim 34, wherein the starting material employed is stone clay including an illite portion.
Claim 47
Dependent Claim
55 words
A foamed ceramic element of lightweight construction made in accordance with the process of claim 34 characterized as having a crystalline phase of at least about 10 percent by weight, a water absorption characteristic nearly zero, a diffusion resistance factor which is practically infinite, a thermal conductivity of between about 0.08 to about 0.2 kcal/m·h·°C.
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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) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |