JP2000044355A - Alumina cement composition and prepared unshaped refractory using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an alumina cement composition good in fluidity, capable of providing a long pot life and ensuring a moderate curing time and good strength developing properties and to provide a prepared unshaped refractory using the same alumina cement composition. SOLUTION: This alumina cement composition contains calcium aluminate and a succinic acid type copolymer or contains the calcium aluminate, α-alumina and the succinic acid type copolymer. Furthermore, the composition contains a defoaming agent. The prepared unshaped refractory contains the alumina cement composition and a refractory aggregate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alumina cement composition used as a lining material for a blast furnace tapping gutter, a mixed iron wheel, a ladle, a tundish, and the like, and an amorphous refractory using the same.

[0002]

2. Description of the Related Art Alumina cement which has been used in combination with various hardening modifiers has been proposed to improve the fluidity, pot life, hardening time, and strength development of alumina cement. Japanese Unexamined Patent Publication No. Sho 49-52216,
JP-A-50-28090, JP-A-55-75947, JP-A-55-94747
No. 75948 and JP-A-55-121933). However, these alumina cements have not been sufficiently satisfactory in performance such as good fluidity, a long pot life, and an adequate curing time and good strength development. That is, when the fluidity and the pot life are improved, the curing is delayed, and the strength development becomes worse. Conversely, when the curing time and the strength development are improved, the fluidity and the pot life cannot be obtained. There were issues such as a strong tendency to conflict.

As a result of intensive studies on the above problems, the present inventor has found that by combining specific materials, it is possible to secure good curing time and excellent strength development without impairing fluidity and pot life. To complete the present invention.

[0004]

That is, the present invention is an alumina cement composition containing calcium aluminate and a succinic acid type copolymer, comprising calcium aluminate, α-alumina and succinic acid type copolymer. An alumina cement composition containing a copolymer, and further comprising the alumina cement composition containing an antifoaming agent, and an amorphous form containing the alumina cement composition and a refractory aggregate. Refractory.

Hereinafter, the present invention will be described in detail.

[0006] Calcium aluminate to be used in the present invention, CaO source such as limestone or burnt lime, Al ₂ natural raw materials such as high-purity alumina and bauxite obtained was purified by purification methods such as the buyer processes red bauxite, etc. O
₃ sources and, if necessary, SiO ₂ sources such as silica stone and silica are blended so as to have a predetermined component ratio, and an electric furnace, a reverberatory furnace,
Clinker obtained by melting and / or firing in equipment such as a vertical furnace, open hearth, shaft kiln, and rotary kiln is crushed. When the calcium aluminate of the present invention is produced by a melting method, a CaO source, an Al ₂ O ₃ source, and a SiO ₂ source, if necessary, are mixed at a predetermined ratio, or mixed and ground, or after partial mixing, Further, the mixture is pulverized and, for example, clinker obtained by melting at a temperature of 1600 ° C. or more using an electric furnace is pulverized to obtain the calcium aluminate of the present invention. When the calcium aluminate of the present invention is produced by the firing method, the raw materials similarly mixed are, for example, 1,000 to 1,60 using a rotary kiln.
The clinker obtained by firing at a temperature of 0 ° C. is pulverized to obtain the calcium aluminate of the present invention. For pulverization of calcium aluminate, it is possible to use a pulverizer, such as a roller mill, a jet mill, a tube mill, a ball mill, and a vibration mill, which is usually used for fine pulverization of a powder mass. Calcium aluminate of the present _{invention, CaO · Al 2 O 3 (} CA), CaO · 2Al 2 O 3 (CA 2), 12CaO
・ It contains one or two or more mineral compositions selected from 7Al ₂ O ₃ (C ₁₂ A ₇ ) and 2CaO ・ Al ₂ O ₃・ SiO ₂ (C ₂ AS). , CaO · TiO _2, further generated by impurities mixed from the raw material _{(CT), 4CaO · Al 2} O 3 · Fe 2 O
Those containing impurities having a mineral composition such as ₃ (C ₄ AF) can also be used.

As a method for determining the mineral composition, there are a method of measuring the intensity ratio of diffraction lines, an internal standard method, a Zevin method, an X-ray diffraction peak separation method, and the like. In the present invention, any of these methods can be used for the determination. . The method of measuring the intensity ratio of diffraction lines referred to here is a value that relatively expresses the diffraction intensity of each mineral, and the internal standard method is a method in which an internal standard substance and a sample are mixed at a fixed ratio, This is a method in which a calibration curve is prepared and analyzed using a standard sample whose concentration is known, utilizing the fact that a linear relationship is obtained between the concentration and the diffraction line intensity ratio. The Zevin method measures the average mass absorption coefficient of a sample and the diffraction line intensity ratio,
This is a method of quantifying each crystal phase by solving an n-order simultaneous equation. The average mass absorption coefficient can be calculated by quantifying the components of a sample by X-ray fluorescence analysis or chemical analysis. In addition, it can be quantified by an X-ray diffraction peak separation method. In this method, measurement is performed from a crystal or a glass phase of a sample. In the present invention, any method can be used to quantify the mineral composition, but it is preferable to use a diffraction line intensity ratio measuring method or Zevin method, which is simple and accurate.

CA, CA ₂ , C in calcium aluminate
The proportions of ₁₂ A ₇ and C ₂ AS are not particularly limited, but usually, CA ₂ is 70% by weight or less, C ₁₂ A ₇ is 20% by weight or less, and C ₂ AS is 20% by weight or less. preferable. When the content of CA ₂ exceeds 70% by weight, and when the content of C ₂ AS exceeds 20% by weight, the curing tendency tends to be exhibited, and when the content of C ₁₂ A ₇ exceeds 20% by weight, the pot life tends to be difficult to secure. . The average particle size of calcium aluminate is related to the fluidity, curability, and strength development properties, which are important properties of amorphous refractories using it, and is important for obtaining the required properties. Preferably, it is 5 μm or less. If it exceeds 10 μm, the fluidity tends to decrease.

The α-alumina used in the present invention is made into an alumina cement by mixing with calcium aluminate. The α-alumina has a required quality when mixed with an amorphous refractory containing alumina cement and a refractory aggregate. Although it is determined as appropriate according to, fluidity, curability, strength development, spalling resistance, and the surface to reduce the shrinkage ratio, etc., should be carefully performed to greatly affect the properties of alumina cement. . α-alumina is intended to impart high-temperature strength developability and volume stability, and is a purified alumina obtained by firing a highly purified aluminum hydroxide by a Bayer process or the like, for example, in a rotary kiln,
Usually, it is called high-purity alumina, Bayer alumina, easily sintered alumina, lightly burned alumina, or the like. α-
The purity of alumina is preferably as high as possible, and Al ₂ O ₃
It is preferably at least 90% by weight, more preferably at least 98% by weight. Alumina manufactured by a usual buyer process can ensure a purity of 90% by weight or more of Al ₂ O ₃ . Additionally, alpha-alumina, a Na ₂ O content of the impurities in addition to the Al ₂ O ₃ purity problem, when the alumina cement and Na ₂ O amount is large, reduction of the fluidity, reduction in the refractory , And problems such as shrinkage at high temperatures occur, the Na ₂ O content is preferably small, preferably 0.5% by weight or less, and 0.3% by weight or less.
More preferably, a low-soda type having a content of less than 10% by weight is used. α
-Alumina has an average primary particle diameter of 20 to
It is about 100 μm, preferably 30 to 60 μm, more preferably 40 to 50 μm. If it is less than 20 μm, the fluidity tends to decrease, and if it exceeds 100 μm, the sintering strength of the amorphous refractory tends to decrease. Normal,
The primary particle diameter is related to the precipitation rate of aluminum hydroxide in the Bayer process. When the precipitation rate is reduced, a particle having a large particle diameter is obtained, and when the precipitation rate is increased, a particle having a small particle diameter is obtained. The average particle diameter of the α-alumina after pulverization is preferably 10 μm or less, more preferably 5 μm or less. If it exceeds 10 μm, the high-temperature strength development when used for irregular-shaped refractories tends to decrease. The index of the degree of firing of α-alumina is the specific surface area by the BET method,
It is preferably at most 10 m ² / g, more preferably at most 5 m ² / g. The degree of sintering indicates that the larger the specific surface area, the lighter the sintering type alumina. When used at a high temperature, the sintering property is excellent but the shrinkage is also large. If the specific surface area of α-alumina is large, the fluidity of the alumina cement decreases, and if it is small, the fluidity tends to improve.
Also, when the specific surface area is large, amorphous refractories containing α-alumina, although having improved sinterability at high temperatures, due to over-sintering, spalling resistance is reduced and shrinkage tends to increase. Show. Amorphous refractories containing α-alumina having a small specific surface area tend to have low shrinkage and low sintering strength. The amount of α-alumina is preferably from 0 to 50 parts by weight, based on 100 parts by weight of calcium aluminate.
There is a tendency that strength developability decreases.

In the present invention, the method of mixing and pulverizing when producing alumina cement from calcium aluminate and α-alumina is as follows: α-alumina is pulverized by itself to a particle size of about calcium aluminate and then pulverized calcium aluminate And pulverization by mixing with calcium aluminate clinker. In the present invention, a mixture of pulverized with clinker of calcium aluminate is more uniformly mixed with α-alumina in alumina cement, and when used as an amorphous refractory, a hardened body structure becomes uniform, corrosion resistance is improved, and the like. The effect described above is preferably obtained.

In the present invention, an alumina cement composition is prepared by blending a succinic copolymer with an alumina cement containing calcium aluminate or calcium aluminate and α-alumina.

The succinic acid type copolymer used in the present invention is a copolymer having a succinic acid type group and a copolymerizable monomer group. Here, the succinic acid type group means maleic acid, maleic anhydride, maleic acid salt, maleic acid monoester, maleic acid monoester salt, maleic acid diester, maleic acid diester salt, fumaric acid, fumarate, fumaric acid monoester. It is a group obtained by copolymerization of a monomer such as an ester, fumaric acid monoester salt, fumaric acid diester, and fumaric acid diester salt with a copolymerizable monomer. The copolymerizable monomer group is a group obtained by polymerization of a copolymerizable monomer. The copolymerizable monomer is not particularly limited, but, for example, styrene, α-methylstyrene, and an aromatic vinyl monomer such as vinyl toluene, and a vinyl ester monomer such as vinyl acetate and vinyl propionate. Olefin monomers such as ethylene, propylene, and isobutylene, and vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, and polyoxyethylene vinyl ether. No. The compounding ratio of the succinic acid type group and the copolymerizable monomer group is 7/3 to 5 / by weight ratio of succinic acid type group / copolymerizable monomer group.
5 is preferred. Outside this range, the pot life extension effect tends to decrease. The method for producing the succinic copolymer (hereinafter referred to as polymer) is not particularly limited,
There are a method of producing by copolymerizing each monomer, and a method of producing by copolymerizing and / or neutralizing a copolymer of each monomer. In the present invention, the polymer is one that imparts the fluidity of calcium aluminate or alumina cement and the effect of extending the pot life, and in particular, the one obtained by copolymerizing a maleic acid monoester monomer with a styrene monomer. preferable.
Specifically, a monoester copolymer or the like, which has a branch, is preferable. As the alkali salt of the polymer, a sodium salt, a potassium salt, an ammonium salt, and the like can be used, but the use of a sodium salt is preferable because of availability. In particular, in order to improve the fluidity and the pot life extending effect, it is preferable to use a sodium salt of a monoester copolymer, especially a water-soluble copolymer having a low degree of polymerization and a solid content of 90% by weight. % Or more, the slurry viscosity at 25 ° C. of the aqueous slurry having a concentration of 40% by weight is 10,000 to 15,000 cps.
These are preferred because they improve the fluidity of calcium aluminate and alumina cement and provide an effect of extending the pot life. In the present invention, the ionicity and pH of the aqueous slurry of the polymer are not particularly limited, but the pH of the 1% by weight slurry at 25 ° C. is anionic.
Is preferably neutral to alkaline, and in particular, p
Those in which H is 7 to 10 are more preferred. The polymer is preferably of a powder type in terms of handling. Powderization of the polymer can be performed by subjecting the liquid product to a drying treatment using a dryer such as a spray dryer. The blending amount of the polymer is not particularly limited, and the combination can be changed according to the material blending.
The amount is preferably 0.1 to 5 parts by weight based on 100 parts by weight of calcium aluminate or alumina cement. When the amount is less than 0.1 part by weight, the fluidity and the pot life extension effect are insufficient, and when the amount exceeds 5 parts by weight, the amount of air entrainment increases, and bubbles are entrained in the kneaded material, so that the curing strength of the cured body tends to decrease. There is.

In the present invention, it is effective to use an antifoaming agent in combination with an alumina cement composition containing alumina cement and a polymer in order to suppress a decrease in the strength of the amorphous refractory. Antifoaming agents are intended to prevent bubbles from being entrained when alumina cement and a polymer are used in combination.Specifically, fats and oils such as sesame oil, fatty acids such as stearic acid, octyl alcohol, etc. Alcoholic,
Examples thereof include fatty acid esters such as polyhydric alcohols such as sorbitan fatty acid esters and partial esters of fatty acids, and polyethers such as polyoxyethylene polyoxypropylene ether, and silicones. Commercially available products include "TSA732" (trade name, manufactured by Toshiba Silicone Co., Ltd.), "Caralin 302" (trade name, manufactured by Sanyo Kasei Kogyo Co., Ltd.), "Pronal 502" (trade name, manufactured by Toho Chemical Co., Ltd.), and "anti-home E-20" (trade name, manufactured by Kao Corporation). , And the product name “SN-
DF14HP "and the like. The amount of the defoamer used is not particularly limited, but is appropriately determined by the type of alumina cement to be combined and the amount of the polymer used, and is blended to such an extent that the fluidity and the pot life extension effect are not reduced. Is preferred. Specifically, the amount is preferably 0.001 to 0.2 parts by weight based on 100 parts by weight of the alumina cement composition. Below 0.001 parts by weight, the amount of air entrainment is large,
If the amount exceeds 0.2 parts by weight, workability tends to decrease, and the pot life tends to be short, and improvement in the defoaming effect cannot be expected.

In the present invention, an amorphous refractory is obtained by blending an alumina cement composition and a refractory aggregate. Examples of the refractory aggregate include magnesia such as fused magnesia, sintered magnesia, natural magnesia, and light-burned magnesia, magnesia spinel such as fused magnesia spinel and sintered magnesia spinel, fused alumina, sintered alumina, light-fired alumina, and Alumina such as sintered alumina, and ultrafine powders such as silica fume, colloidal silica, lightly fired alumina, and easily sintered alumina, etc., fused silica, calcined mullite, chromium oxide, bauxite, andalusite, sillimanite, chamotte, silicate Examples include rock, rock, clay, zircon, zirconia, dolomite, perlite, vermiculite, brick waste, pottery waste, silicon nitride, boron nitride, silicon carbide, and silicon nitride iron. In particular, in the amorphous refractory of the present invention, one or more refractory aggregates selected from magnesia spinel, alumina, and ultrafine powder are used in terms of corrosion resistance, durability, and fire resistance. Is preferred. Magnesia spinel is a mixture of MgO source such as magnesium hydroxide and calcined magnesia and Al ₂ O ₃ source such as aluminum hydroxide and calcined alumina in a specified ratio, and a baking device such as rotary kiln. It is used for the reaction and sintering at a temperature of about 1,800 to 1,900 ° C, the one melted by a melting device such as an electric furnace, crushed to a predetermined size, sieved, and the fired one. A mixture of melted materials and the like. The weight ratio of MgO / Al ₂ O ₃ in magnesia spinel is preferably from 1/1 to 0.1 / 1, and from 0.4 / 1 to 0.2 / 1.
Is more preferable from the viewpoint of excellent durability. What is alumina?
Al ₂ O ₃ sources such as aluminum hydroxide and calcined alumina,
Sintered and / or molten material is crushed to a predetermined size by a firing device such as a rotary kiln or a melting device such as an electric furnace, and sieved.
-Al ₂ O ₃ and aluminum oxide represented as β-Al ₂ O _{3 and the} like, which is called sintered alumina, calcined alumina, easily sintered alumina, etc., usually, Al ₂ O ₃ is 90 It is most preferred to use α-alumina containing not less than% by weight. Also,
It is also possible to use alumina, zirconia, etc. obtained by melting alumina and zirconia and having improved heat spalling resistance.

In the present invention, the refractory aggregate is usually 5 to 3
Particles having a particle size of mm, 3 to 1 mm, 1 to 0 mm, under 200 mesh, under 325 mesh, etc. are blended according to required physical properties.

In the present invention, as the refractory aggregate, it is possible to use an ultrafine powder having a fine particle diameter. Ultrafine powder is a refractory fine powder in which particles having a particle diameter of 10 μm or less account for 80% by weight or more, and have an average particle diameter of 1 μm.
m and a specific surface area of 10 m ² / g or more according to the BET method are preferable from the viewpoint of ensuring fluidity and exhibiting high strength when mixed with the amorphous refractory. Specifically, inorganic fine powders such as silica fume, colloidal silica, easily sintered alumina, amorphous silica, zircon, silicon carbide, silicon nitride, chromium oxide, and titanium oxide can be used.
The use of silica fume, colloidal silica, and easily sintered alumina is preferred.

The mixing ratio of the alumina cement composition and the refractory aggregate in the amorphous refractory of the present invention should be appropriately determined depending on the construction site, and is not particularly limited. Among the parts by weight, the alumina cement composition is preferably 2 to 20 parts by weight. If the amount is less than 2 parts by weight, strength developability tends to decrease, and if it exceeds 20 parts by weight, corrosion resistance tends to decrease.

The method for producing the amorphous refractory of the present invention is not particularly limited, and each material is blended in a predetermined ratio according to the usual method for producing an irregular refractory, and the V-shaped blender is used. It is also possible to perform uniform mixing using a mixer such as a corn blender, a Nauta mixer, a bread mixer, and an omni mixer, or to perform kneading at a predetermined ratio and directly weigh the kneader. .

In the present invention, a curing retarder (hereinafter referred to as a retarder) generally used in the field of alumina cement can be blended as required. Examples of the retarder include phosphoric acids, boric acids, silicofluorides, oxycarboxylic acids, polycarboxylic acids, polyoxyalkylenes,
And at least one selected from the group consisting of saccharides and saccharides. Phosphoric acids include hexametaphosphoric acid, tripolyphosphoric acid, ultraphosphoric acid, pyrophosphoric acid, and orthophosphoric acid or salts thereof, and hexametaphosphoric acid and tripolyphosphoric acid or salts thereof are preferable because of their excellent dispersing action. More preferably, the pH is alkaline and the pH is 8.0 to 11.0. Examples of the salts of phosphoric acids include sodium, potassium, and calcium salts, and use of a sodium salt is preferable because of availability. The particle size of phosphoric acids is 20
Those having a mesh size of 0 mesh or less are preferable because they are easily dissolved at the time of kneading and have an excellent dispersing action. In terms of quality, commercially available products such as pharmaceuticals and food additives can be used. Boric acids include boric acid and its alkali salts such as sodium salt, potassium salt and calcium salt. Of these, boric acid having a strong curing retardation effect is preferably used. The purity of boric acids is not particularly limited, but those industrially purified at present can be used. Further, the particle size of the boric acid is preferably smaller so as to be easily dissolved in water, and is preferably 100 mesh or less,
200 mesh or less is more preferable. As the silicofluoride, use of sodium silicofluoride, potassium silicofluoride, magnesium silicofluoride or the like is preferable. Among these, use of sodium silicofluoride is preferred because of its strong curing retarding effect. Although the purity of the silicofluoride is not particularly limited, it is possible to use those that are currently industrially purified, and the purity of the intended silicofluoride is
It is preferable to use one having about 80% by weight or more. The particle size of the silicon fluoride is preferably as small as possible so as to be easily dissolved in water, and is preferably 100 mesh or less, more preferably 200 mesh or less.

As the oxycarboxylic acids, citric acid,
Gluconic acid, tartaric acid, malic acid, and lactic acid or salts thereof. Examples of the salts of oxycarboxylic acids include sodium, potassium, and calcium salts, and use of a sodium salt is preferred because of availability. The particle size of oxycarboxylic acids is less than 200 mesh,
It is preferable because it is easily dissolved at the time of kneading and has an excellent dispersing action. In terms of quality, commercially available food additives can be used.

Examples of the polycarboxylic acids include polyacrylic acids, polymethacrylic acids, acrylic acid / methacrylic acid copolymers, and polyitaconic acids. Examples of the polyacrylic acids include polyacrylic acid and its derivatives or alkali salts thereof, and polyacrylate copolymers and alkali salts thereof, and the copolymer is preferably branched. As polymethacrylic acids, non-functional monomers such as methyl methacrylate, monofunctional monomers such as diethylaminoethyl methacrylate,
And methacrylic monomers classified as polyfunctional monomers such as ethylene dimethacrylate and the like, polymethacrylic acid or an alkali metal salt thereof, and a methacrylate synthetic resin containing a copolymer. The acrylic acid / methacrylic acid copolymer is a copolymer having a molecular weight of 5,000 to 20,000, and is a copolymer of acrylic acid and methacrylic acid. The copolymerization ratio of acrylic acid and methacrylic acid is preferably from 9/1 to 4/6 by weight ratio of acrylic acid / methacrylic acid,
A copolymer having a ratio of 2/5/5 is more preferable because of excellent dispersing action. Particularly preferred copolymer combinations have a weight ratio of sodium acrylate / sodium methacrylate of 8 /
2/5/5. If the proportion of acrylic acids is too high,
Fluidity and pot life tend to be faster, and if the proportion of acrylic acid is too small, the viscosity at the time of kneading increases, which not only tends to delay curing, but also tends to make copolymerization impossible. is there. Examples of the polyitaconic acids include those having a molecular weight of 5,000 to 10,000, polyitaconic acid, derivatives thereof, alkali salts thereof, and polyitaconate ester copolymers or alkali salts thereof, and the copolymer is branched. Is preferred. As the alkali salt of the polycarboxylic acid used in the present invention, a sodium salt, a potassium salt, a calcium salt and the like can be used, but the use of a sodium salt is preferable because of availability. Above all, a slurry viscosity of 40% by weight at 25 ° C., which is soluble in water and has a solid content of 90% by weight or more and measured by a B-type viscometer at 1
The use of a soluble type of not more than 0,000 cps is preferable from the viewpoint of improving the fluidity of the alumina cement, and 1,000 cps
More preferably, the following are used: In the present invention, the ionicity and pH of the slurry of the polycarboxylic acids are not particularly limited, but when blended with alumina cement, in order to obtain greater fluidity, the polycarboxylic acids are anionic, and It is important that the pH of a 1% by weight slurry at 25 ° C. is neutral to alkaline, and a pH of 7.5 to 10 is particularly preferable. The polycarboxylic acids are preferably of a powder type from the viewpoint of handling. The pulverization of the polycarboxylic acids can be carried out by subjecting the liquid product to a drying treatment with a drier such as a spray drier. Specific examples of polyoxyalkylenes include polyalkylene glycol acrylate copolymers, polyalkylene glycol alkenyl ether-maleic anhydride copolymers, and polyalkylene glycol monoester monomers / methacrylic acid copolymers. Coalescence and the like. Examples of the saccharide include aldehydes and ketones of polyhydric alcohols, and acids and polyhydric alcohols themselves and derivatives and substituted products thereof, and specific examples include glucose, fructose, dextrin, and sucrose.

The combination of types of retarders can be appropriately selected depending on the alumina cement, and is not particularly limited. The combination can be changed according to the material composition. The amount of use of these retarders is preferably 0.1 to 5 parts by weight based on 100 parts by weight of alumina cement from the viewpoint of obtaining a pot life extending effect. If the amount is less than 0.1 part by weight, the fluidity and the effect of extending the pot life may be insufficient, and if it exceeds 5 parts by weight, the curing may be retarded. In the present invention, the method of blending the retarder is not particularly limited, and each additive is blended so as to have a predetermined ratio, and clinker of calcium aluminate or pulverized calcium aluminate or clinker and α-alumina, V Mix uniformly using a mixer such as a mold blender, cone blender, Nauta mixer, bread mixer, omni mixer, or after mixing with clinker or clinker and α-alumina at a predetermined ratio, vibrating mill, tube mill , A ball mill, and a roller mill. Further, in the present invention, it is possible to heat-treat each individual retarder or a mixture of retarders at a temperature of 100 to 200 ° C. for 30 minutes or more, preferably 60 minutes to 180 minutes, for drying or light baking. It is preferable because the fluidity when blended into the alumina cement composition is improved. Particularly, the effect of heat treatment at 120 to 180 ° C. is remarkable. Retarder of the present ^{invention, GC-MS, C 13 -NMR} , it is possible to analyze the like HPLC, instrumental analysis and neutron activation analysis or ion chromatography, and FT-IR.

Further, a foaming agent such as metal aluminum or metal magnesium which reacts with alkaline water to generate hydrogen gas, an organic fiber such as vinylon fiber, polypropylene fiber and vinyl chloride fiber may be added to the amorphous refractory of the present invention. N ₂ gas generating exploded fibers are fibers that generates N ₂ gas by heating, a basic colloids such aluminum lactate, and, if necessary explosion prevention materials such as humic acids, explosion object of preventing the time of curing the dried It is possible to mix. Further, in order to avoid material separation between the amorphous refractory of the present invention and moisture, it is also possible to blend a thickener such as methylcellulose, carboxymethylcellulose, a modified polyacrylamide or a copolymer thereof, and polyvinyl alcohol. is there.

The amount of kneading water used for kneading the irregular refractory is set to such an extent that it can be poured normally, and is greatly affected by the particle size composition and the porosity of the refractory aggregate. It is about 5 to 8 parts by weight based on parts by weight.

[0025]

The present invention will be described below more specifically based on experimental examples.

EXPERIMENTAL EXAMPLE 1 A CaO source, an Al ₂ O ₃ source, and a SiO ₂ source were blended at a predetermined ratio.
After melting at 1,400 to 1,700 ° C. using an electric furnace, the mixture was quenched or allowed to cool to produce a clinker of calcium aluminate of CA, CA ₂ , C ₁₂ A ₇ , and C ₂ AS. The produced calcium aluminate clinker and polymer were blended as shown in Table 1 and pulverized by a vibration mill so as to have an average particle diameter of 5 μm to prepare an alumina cement composition. In a 20 ° C constant temperature room, 10 parts by weight of the prepared alumina cement composition, 70 parts by weight of refractory aggregate A, 10 parts by weight of refractory aggregate B, 10 parts by weight of refractory aggregate C10
Parts by weight and 6.3 parts by weight of water were mixed and kneaded with a mortar mixer for 3 minutes to prepare an amorphous refractory. About the produced amorphous refractories, fluidity, pot life, curing time,
Curing strength, drying strength, firing strength, and corrosion resistance were measured. The results are also shown in Table 1. For comparison,
The same was done using naphthalene sulfonate as an additive instead of polymer. The results are also shown in Table 1.

<Materials> CaO source: quick lime powder, 1 mm below Al ₂ O ₃ source: calcined alumina, 150 μm below SiO ₂ source: silica powder, 1 mm below Refractory aggregate A: electrofused alumina, 5-1 mm 20 weight Part, 1-0
mm25 parts by weight, 48F15 parts by weight, 325 F10 parts by weight Refractory aggregate B: Sintered spinel, 200 F Refractory aggregate C: Ultra fine powder, sintered alumina, average particle diameter 1 μm Polymer α: Succinic acid type copolymer Sodium salt, solid content 100% by weight Polymer β: ammonium salt of succinic acid copolymer, solid content 100% by weight Additive: sodium salt of naphthalenesulfonic acid-based condensate, solid content 100% by weight

<Measurement method> Mineral composition: Diffraction intensity ratio d value by X-ray diffractometer “RADIIB” manufactured by Rigaku Corporation, CA = 4.67 °, CA ₂ = 4.45 °, C ₂ AS =
Using the intensity of the diffraction line of 2.85 °, α-alumina = 2.55 °
Calculated by Zevin method Fluidity: The kneaded material left for 30 minutes after kneading for 3 minutes is used to measure the spread diameter after tapping 15 times with a flow table according to JIS R 2521. Transfer the fixed refractory to a plastic bag and wait until the fluidity is lost. Curing time: Transfer a small amount of the non-conformable refractory to a polybeaker, measure with a platinum resistance thermometer and a dot recorder, and inject water. The time from the peak to the exothermic peak was taken as the curing time. Curing strength: Cut out to 4 x 4 x 16 cm and measured with a hydraulic measuring machine. Dry strength: After drying the test piece at 110 ° C for 24 hours, cool it down to room temperature and measure with a hydraulic measuring machine. Firing strength: Test the dried test piece Place in a siliconitic furnace, heat up to 1,000 ° C at a rate of 10 ° C / min, above 1,000 ° C at a rate of 5 ° C / min to 1,500 ° C, hold for 3 hours, allow to cool to room temperature, Measurement Corrosion resistance: A test piece cut into 4 x 4 x 16 cm is 110 ° C
, And calcined at 1,500 ° C for 3 hours to obtain CaO / SiO ₂
= 2.0, 1,550 ° C containing 500 g of slag with 10% by weight of total Fe
The erosion dimension in the depth direction after immersion in a high frequency furnace for 3 hours was measured. If the erosion dimension exceeds 3.0mm, it cannot be used as a refractory.

[0029]

[Table 1]

As shown in the table, the amorphous refractory blended with the alumina cement composition of the present invention has better fluidity, a longer pot life, and an appropriate curing time as compared with Comparative Examples. High strength development was obtained.

Experimental Example 2 50% by weight of CA, 10% by weight of CA ₂ , 20% by weight of C ₁₂ A ₇ and C ₂
70 parts by weight of calcium aluminate containing 20% by weight of AS and 30 parts by weight of α-alumina having an average particle diameter and a BET specific surface area shown in Table 2 were mixed to form alumina cement, and polymer α was converted to 100 parts by weight of alumina cement. On the other hand, it carried out similarly to Experimental example 1 except having mix | blended 0.5 weight part and made the alumina cement composition. The results are also shown in Table 2.

<Materials Used> α-Alumina: Commercial product

<Measurement method> Average particle diameter: using a laser diffraction type particle size distribution analyzer manufactured by Shimadzu Corporation BET specific surface area: using a Cantersorb manufactured by Yuasa Ionics

[0034]

[Table 2]

As shown in the table, the amorphous refractory containing the alumina cement composition of the present invention has good fluidity,
The pot life was long, an appropriate curing time and good strength development were obtained.

Experimental Example 3 CA 50% by weight, CA ₂ 10% by weight, C ₁₂ A ₇ 20% by weight, and C ₂
100 parts by weight of calcium aluminate containing 20% by weight of AS, 0.5 part by weight of polymer α, and an antifoaming agent shown in Table 3 were mixed, and pulverized to an average particle diameter of 5 μm with a vibration mill to prepare an alumina cement composition. Except for this, the procedure was the same as in Experimental Example 1. The results are also shown in Table 3.

<Materials used> Antifoaming agent a: alcohol-based antifoaming agent, commercially available product Defoaming agent b: polyether-based antifoaming agent, commercially available product Defoaming agent c: polyether-based antifoaming agent, commercially available product

[0038]

[Table 3]

As shown in the table, the amorphous refractory blended with the alumina cement composition of the present invention has good fluidity,
The pot life was long, an appropriate curing time and good strength development were obtained.

[0040]

As is clear from the above examples, the alumina cement composition of the present invention has performances that could not be achieved with conventional products, that is, it has good fluidity and a long pot life. An appropriate curing time and good strength development can be ensured. Further, the alumina cement composition of the present invention can be widely used in the field of refractories such as refractory concrete and refractory castables, as well as in the field of civil engineering and construction materials.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B22D 41/02 B22D 41/02 A C21B 7/14 307 C21B 7/14 307 C21C 1/06 C21C 1/06 7/00 7/00 Q F27D 1/00 F27D 1/00 NF term (reference) 4G033 AA02 AB01 AB02 AB23 4K013 CF12 CF13 CF15 CF19 4K014 AD04 AD23 AD25 AE00 4K051 AA01 AA02 AA05 AA06 AB03 AB05 BB03 BB06 BE00

Claims (4)

[Claims] 1. An alumina cement composition comprising calcium aluminate and a succinic acid type copolymer. 2. An alumina cement composition containing calcium aluminate, α-alumina, and a succinic acid-type copolymer. 3. The method according to claim 1, further comprising an antifoaming agent.
Or the alumina cement composition according to 2. 4. An amorphous refractory comprising the alumina cement composition according to claim 1 and a refractory aggregate.