US4568652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Soluble additives to improve high temperature properties of alumina refractories
Assignee: United States Department of the Interior
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Filing: 1984-10-15
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Granted: 1986-02-04
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Expires: 2004-10-15
Abstract
Abstract A method for improving the high temperature properties of 42 to 70 percent by weight Al2O3 containing alumina refractories by adding thereto a soluble metal compound and firing to at least 1450 DEG C. for a time sufficient to convert the soluble metal compound to a refractory oxide or phase and for the refractory oxide or phase to react with the non-Al2O3 constituents of the refractory for preventing or reducing the presence or effect of detrimental compounds or phases on the high temperature properties of the refractory. The resulting relatively low Al2O3 content, porous, alumina refractory includes within its pores from 1 to 10% by weight of a refractory oxide or phase and is characterized by high temperature property values substantially greater than the corresponding values for the same refractory body without said refractory oxide or phase in its pores.
Inventors
- 👤 Arthur V. Petty, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:27
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B35/00; C04B35/01; C04B35/10; C04B35/101; C04B35/105; C04B35/16; C04B35/18; C04B41/45; C04B41/50; C04B41/5025; C04B41/80; C04B41/81; C04B41/85; C04B41/87
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
168 words
A method for improving the high temperature properties of relatively low Al 2 O 3 content alumina refractories comprising the steps of: providing a porous alumina refractory containing from 42 to 70 percent by weight Al 2 O 3 ; impregnating said refractory with a solution of a soluble compound, said compound containing an ion selected from the group consisting of chromium, mixtures of chromium and iron, zirconium, calcium, molybedenum and tungsten and being capable of conversion to a refractory oxide or phase on being heated to a temperature below the melting point of the alumina refractory; heating said impregnated refractory to a temperature of at least about 1450° C. but less than the melting point of the alumina refractory for a time sufficient to convert the impregnated compound to a refractory oxide or phase and for the refractory oxide or phase to react with the non-Al 2 O 3 constitutents of said refractory for preventing or reducing the presence of high temperature property detrimental compounds or phases.
Claim 2
Independent Claim
168 words
A method for improving the high temperature properties of relatively low Al 2 O 3 content alumina refractories comprising the steps of: providing a porous alumina refractory containing from 42 to 70 percent by weight Al 2 O 3 ; impregnating said refractory with a solution of a soluble compound, said compound containing an ion selected from the group consisting of chromium, mixtures of chromium and iron, zirconium, calcium, molybedenum and tungsten and being capable of conversion to a refractory oxide or phase on being heated to a temperature below the melting point of the alumina refractory; heating said impregnated refractory to a temperature of at least about 1450° C. but less than the melting point of the alumina refractory for a time sufficient to convert the impregnated compound to a refractory oxide or phase and for the refractory oxide or phase to react with the non-Al 2 O 3 constitutents of said refractory for preventing or reducing the presence of high temperature property detrimental compounds or phases.
Claim 3
Dependent Claim
15 words
A method, as claimed in claim 1, wherein said step of impregnating is vacuum impregnating.
Claim 4
Dependent Claim
22 words
A method, as claimed in claim 1, wherein said step of impregnating comprises soaking said refractory in a solution containing said ion.
Claim 5
Dependent Claim
25 words
A method, as claimed in claim 1, wherein said step of impregnating comprises adding said soluble compound to a refractory dry mix prior to forming.
Claim 6
Dependent Claim
25 words
A method, as claimed in claim 1, wherein said step of impregnating comprises adding said soluble compound to a refractory castable, ramming, or gunning mix.
Claim 7
Dependent Claim
23 words
A method, as claimed in claim 1, wherein said refractory is impregnated with from 1 to 10% by weight of said soluble compound.
Claim 8
Dependent Claim
23 words
A method, as claimed in claim 6, wherein said body is impregnated with from 3 to 10% by weight of said soluble compound.
Claim 9
Independent Claim
27 words
A method, as claimed in claims 6 or 7, wherein said ion is selected from the group consisting of molybdenum, chromium and mixtures of chromium and iron.
Claim 10
Independent Claim
25 words
A method, as claimed in claims 6 or 7, wherein said soluble compound is selected from the soluble oxides, chlorides and nitrates of said ions.
Claim 11
Dependent Claim
26 words
A method, as claimed in claim 9, wherein said soluble compound is selected from molybdenum trioxide, chromium trioxide and mixtures of chromium trioxide and ferric chloride.
Claim 12
Dependent Claim
21 words
A method, as claimed in claim 1, wherein said refractory has an apparent porosity of from about 11 to 19 percent.
Claim 13
Dependent Claim
21 words
A method, as claimed in claim 1, wherein said refractory has an apparent porosity of from about 12 to 16 percent.
Claim 14
Dependent Claim
93 words
A relatively low Al 2 O 3 content, porous, alumina refractory body comprising from 42 to 70 percent by weight Al 2 O 3 , balance SiO 2 and impurities, said body including within its pores from 1 to 10% by weight of a refractory oxide or phase of an ion selected from the group consisting of chromium, mixtures of chromium and iron, zirconium, calcium and molybdenum and characterized by high temperature property values substantially greater than the corresponding values for the same refractory body without said refractory oxide content in its pores.
Claim 15
Dependent Claim
93 words
A relatively low Al 2 O 3 content, porous, alumina refractory body comprising from 42 to 70 percent by weight Al 2 O 3 , balance SiO 2 and impurities, said body including within its pores from 1 to 10% by weight of a refractory oxide or phase of an ion selected from the group consisting of chromium, mixtures of chromium and iron, zirconium, calcium and molybdenum and characterized by high temperature property values substantially greater than the corresponding values for the same refractory body without said refractory oxide content in its pores.
Claim 16
Dependent Claim
43 words
An alumina refractory body, as claimed in claim 13, wherein said refractory oxide or phase is selected from solid solutions of Cr 2 O 3 .Al 2 O 3 and Cr 2 O 3 .Fe 2 O 3 .Al 2 O 3 .
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |