GB2143809A - Rigid coherent gel for binding of refractories - Google Patents

Rigid coherent gel for binding of refractories Download PDF

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Publication number
GB2143809A
GB2143809A GB08414078A GB8414078A GB2143809A GB 2143809 A GB2143809 A GB 2143809A GB 08414078 A GB08414078 A GB 08414078A GB 8414078 A GB8414078 A GB 8414078A GB 2143809 A GB2143809 A GB 2143809A
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United Kingdom
Prior art keywords
gel
double
refractory
grains
chromium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08414078A
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GB8414078D0 (en
Inventor
Thomas James Davies
Harold Garton Emblem
Kenneth Jones
Peter Parkes
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zirconal Processes Ltd
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Zirconal Processes Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB838316866A external-priority patent/GB8316866D0/en
Application filed by Zirconal Processes Ltd filed Critical Zirconal Processes Ltd
Priority to GB08414078A priority Critical patent/GB2143809A/en
Publication of GB8414078D0 publication Critical patent/GB8414078D0/en
Publication of GB2143809A publication Critical patent/GB2143809A/en
Withdrawn legal-status Critical Current

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Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01GCOMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G37/00Compounds of chromium
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/03Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite
    • C04B35/04Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite based on magnesium oxide
    • C04B35/043Refractories from grain sized mixtures
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/03Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite
    • C04B35/04Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite based on magnesium oxide
    • C04B35/043Refractories from grain sized mixtures
    • C04B35/047Refractories from grain sized mixtures containing chromium oxide or chrome ore
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632Organic additives
    • C04B35/6325Organic additives based on organo-metallic compounds
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07FACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F11/00Compounds containing elements of Groups 6 or 16 of the Periodic Table
    • C07F11/005Compounds containing elements of Groups 6 or 16 of the Periodic Table compounds without a metal-carbon linkage
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07FACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F5/00Compounds containing elements of Groups 3 or 13 of the Periodic Table
    • C07F5/06Aluminium compounds
    • C07F5/069Aluminium compounds without C-aluminium linkages

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Compositions Of Oxide Ceramics (AREA)

Abstract

A double alkoxide of chromium and aluminium, for example the isopropoxide is used to bind refractory grains. In an example magnesia grain is mixed into a slurry with the double hydroxide, water, isopropanol and triethanolamine being incorporated as hydrolysis and gellation inducing agents.

Description

SPECIFICATION Improvements in the binding of refractories This invention relates to the binding of refractories.
According to the present invention there is provided a method of forming a rigid coherent gel suitable for binding refractory grains such method comprising the step of causing or allowing a double alkoxide of chromium and aluminium to gel. The gelling sequence comprises an initial hydrolysis followed by a setting of the hydrolysate.
Chromium and aluminium form volatile double alkoxides which can be isoiated as pure compounds.
The double isopropoxide is soluble in isopropanol. When this solution is rendered aqueous for the hydrolysis and treated with triethanolamine, a strongly basic aminoalcohol, (preferably so as to give one bond per metal atom), a rigid coherent gel suitable for binding refractory grain is formed. This gel is especially suitable for binding alumina grain and basic refractory grains.
The addition of chrome to refractory compositions as a way of improving resistance to thermal shock and to erosion by slags is well known. However, if the composition contains silica in the bonding phase the advantages of adding chrome are minimised. Generally, for best results silica should be absent and the chromium present as a chromia- alumina solid solution, if the refractory composition is not basic.
This is achieved in accordance with the invention, as the use of a gel obtained from a chromium-aluminium double alkoxide to bind refractory grain, besides eliminating silica in the bonding phase, produces, after firing, a chromia-alumina solid solution. For best results the gel entraining the refractory grains should be fired under oxidising conditions.
When a chromium-aluminium double alkoxide is used to bind basic grain, e.g. magnesia grain, the oxide residues from the double alkoxide react to form spinels. The grain mixture should contain at least sufficient reactive magnesia to form the spinels. One way of achieving this is to include ball-milled magnesia fines in the grain mix. The formation of spinels is another important feature of the invention.
It should be noted that the simple chromium alkoxides are highly polymerised and therefore do not form useful gels.
The volatile double isopropoxide of chromium and aluminium may be synthesised (J.V.Singh, N.L.Jain and R.C.Mehrotra, Synth. React. Inorg. Met-Org. Chem., 1978, 979) according to equation (1).
CrC13.3THF + 3K [Al(OPri)4] < Cr [AI(OPr')4]3 + 3KCI + 3THF t This double isopropoxide of chromium and aluminium was prepared as described, on a tenfold scale.
The invention will now be described with reference to the following Examples: Example I Gelation conditions - procedure A 4g of the chromium-aluminium double isopropoxide are dissolved in 20 ml dry isopropanol and 0.85ml triethanolamine added. This corresponds to one bond per metal atom. This is the stock solution. As hydrolysis/gelation agent, a mixture of equal parts by volume of water and isopropanol is used. Table 1 gives gel times and gel characteristics.
TABLE 1 Gel characteristics of chromium aluminium double isopropoxide Volume of stock Volume of hydrolysisl Gel time (min) and solution (mI) gelation agent (mI) gel characteristics 10 0.1 No increase in viscosity 10 0.15 Ca.30 - rigid coherent gel suitable for binding refractory grain 10 0.2 Ca.1 - rigid coherent gel Gelation conditions - procedure B 3.16g of the chromium-aluminium double isopropoxide Cr[Al(OPr)4]3 and 1.7ml triethanolamine are dissolved in 20 ml isopropanol. This is solution A. The hydrolysis/gelation agent, solution B, consists of water and isopropanol in equal volumes.
Table 2 gives gel times and gel characteristics.
TABLE 2 Gel characteristics of chromium aluminium double isopropoxide Volume of solution A (ml) Volume of solution B rml) Gel characteristics 2 0.4 Hard brittle gel formed very quickly 2 0.2 Hard brittle gel formed very quickly 2 0.1 Gel formed in 1.5 min.
2 0.05 Gel formed in 2 min.
2 0.025 Gel formed in 13 min.
Example II Preparation of refractory shape To 10 ml stock solution there was added 0.15 ml of the hydrolysis and gelation agent. The resulting mixture was added to 90g Sardamag magnesia grain mix to give a slurry which was cast into a mould.
After about 30 minutes the casting was removed from the mould, then air-dried, baked and fired following standard procedures to give a refractory shape.
The Sardamag grain mix used had the following composition (Sardamag is a Registered Trade Mark).
B.S.410; 1976 sieve Percentage by weight number and aperture - 5 + 10 (-3.35mm + 1.70mm) 30 -10 + 25 (-1.70mm + 600 ,am) 20 -25 + 72 (-600 Fm + 212 Fm) 15 Ball-milled fines 35 The Sardamag grain used was Sardamag 251 SP grade.
The ball-milled fines had the following properties: Awl203 0.25% by weight Fe203 0.22% by weight CaO 1.62% by weight SiO2 0.78% by weight Residue MgO BET surface area 2m2lg (approx.) Surface area by Rigden method 0.25 - 0.30m2/g.
Sardamag 251 SP grain has the following typical analysis: Mineral Weight percent SiO2 0.7 - 0.9 AT203 0.2 - 0.4 Fe2O3 0.15 - 0.3 B203 0.02 - 0.4 CaO 1.8 - 2.3 MgO 95.5 - 96.5 Example III A solution of the double alkoxide Cr [Al(OPr)4]3 in a mixture of triethanolamine and isopropanol was prepared by dissolving 3.16g of the double alkoxide and 1.7ml triethanolamine in 20ml isopropanol. This is solution A.
A mixture of water and isopropanol in equal volumes was also prepared. This is solution B.
0.15ml of solution B was added to 10ml of solution A. This mixture was added to 90g of magnesia grain mix, having the particle size distribution given below, to produce a slurry which was cast into a mould. After about 30 minutes the casting was removed from the mould, then air-dried, baked and fired at 1590 for about 4 hours. The refractory shape obtained had weil-bound grain and good surface characteristics. X-ray diffraction analysis showed the presence of substantial amounts of magnesia-alumina spinel and magnesia-chromia spinel.
Particle size distribution of magnesia grain B.S. 410, 1976 sieve Aperture Percentage by weight - S + 10 -3.55mm + 1.70mm 30 - 10 + 25 -1.70mm + 600 Am 20 - 25 + 72 -6001lm + 212 m 15 Ball-milled fines, BET 35 surface area approx. 2m2/g This Example demonstrates how substantial spinel formation can be induced by the use of a double alkoxide of chromium and aluminium to bind magnesia grain. This concept forms part of the subject of our copending Patent Application of today's date (Our Ref: MJD/JY/1264) The invention can also be used in pressure moulding processes, for instance, the pressure moulding process which is described in British Patent Application No. 2,108,101A.
The procedure of the invention may be used to make the sliding-gate plate inserts described in British Patent Application 2,113,806A.

Claims (11)

1. A method of forming a rigid coherent gel suitable for binding refractory grains such method comprising the step of causing or allowing to gel a double alkoxide of chromium and aluminium.
2. A method as claimed in Claim 1 wherein the double alkoxide is hydrolysed to a gellable hydrolysate by the addition of water.
3. A method as claimed in Claim 2 wherein a basic hydrolysis and gellation catalyst is added.
4. A method as claimed in Claim 3 in which the basic hydrolysis and gelation catalyst is an aminoalcohol.
5. A method as claimed in any of the preceding claims wherein the alkoxide is a double isopropoxide.
6. A method as claimed in either Claim 4 or Claim 5 wherein the double isopropoxide is dissolved in isopropanol and the solution is caused to gel by the addition of water and triethanolamine.
7. A method as claimed in Claim 3 wherein the refractory grains bound are alumina grains or magnesia grains.
8. A method as claimed in any of the preceding claims in which the refractory grains and the gel react on firing to produce at least one spinel.
9. A method as claimed in any of the preceding claims wherein the gel is fired ta form a refractory under oxidising conditions.
10. Methods according to Claim 1 and substantially as hereinbefore described.
11. Refractory shapes formed by a method according to any of the preceding claims.
GB08414078A 1983-06-21 1984-06-01 Rigid coherent gel for binding of refractories Withdrawn GB2143809A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08414078A GB2143809A (en) 1983-06-21 1984-06-01 Rigid coherent gel for binding of refractories

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB838316866A GB8316866D0 (en) 1983-06-21 1983-06-21 Binding of refractories
GB08414078A GB2143809A (en) 1983-06-21 1984-06-01 Rigid coherent gel for binding of refractories

Publications (2)

Publication Number Publication Date
GB8414078D0 GB8414078D0 (en) 1984-07-04
GB2143809A true GB2143809A (en) 1985-02-20

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988001991A1 (en) * 1986-09-09 1988-03-24 Manchem Limited Binders for refractory grain
EP2060250A1 (en) * 2007-11-16 2009-05-20 KPSS Kao Professional Salon Services GmbH Use of alkanolamines for thickening oxidative colouring emulsion

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB710427A (en) * 1950-12-14 1954-06-09 Socony Vacuum Oil Co Inc Method of hydrogel preparation
GB996297A (en) * 1960-11-15 1965-06-23 Werner Hermann Kreidl Improvements in refractory mortars
GB1003745A (en) * 1961-06-07 1965-09-08 Werner Hermann Kreidl Improvements in refractory mortars
GB1350974A (en) * 1970-05-26 1974-04-24 Owens Illinois Inc Double alkoxides and ultra-pure compounds prepared therefrom
GB2063848A (en) * 1979-11-28 1981-06-10 Zirconal Processes Ltd Improvements in the binding of refractory powders
EP0063034A2 (en) * 1981-04-10 1982-10-20 Zirconal Processes Limited Rigid coherent gel
GB2128604A (en) * 1982-10-19 1984-05-02 Harold Garton Emblem Aluminium alkoxide derivates

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB710427A (en) * 1950-12-14 1954-06-09 Socony Vacuum Oil Co Inc Method of hydrogel preparation
GB996297A (en) * 1960-11-15 1965-06-23 Werner Hermann Kreidl Improvements in refractory mortars
GB1003745A (en) * 1961-06-07 1965-09-08 Werner Hermann Kreidl Improvements in refractory mortars
GB1350974A (en) * 1970-05-26 1974-04-24 Owens Illinois Inc Double alkoxides and ultra-pure compounds prepared therefrom
GB2063848A (en) * 1979-11-28 1981-06-10 Zirconal Processes Ltd Improvements in the binding of refractory powders
EP0063034A2 (en) * 1981-04-10 1982-10-20 Zirconal Processes Limited Rigid coherent gel
GB2128604A (en) * 1982-10-19 1984-05-02 Harold Garton Emblem Aluminium alkoxide derivates

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988001991A1 (en) * 1986-09-09 1988-03-24 Manchem Limited Binders for refractory grain
EP2060250A1 (en) * 2007-11-16 2009-05-20 KPSS Kao Professional Salon Services GmbH Use of alkanolamines for thickening oxidative colouring emulsion
WO2009062702A1 (en) * 2007-11-16 2009-05-22 Kpss-Kao Professional Salon Services Gmbh Use of alkanolamines for thickening oxidative colouring emulsion
US8357209B2 (en) 2007-11-16 2013-01-22 Kpss-Kao Professional Salon Services Gmbh Use of alkanolamines for thickening oxidative colouring emulsion

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Publication number Publication date
GB8414078D0 (en) 1984-07-04

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