JPH07232956A - Alumina cement composition - Google Patents

Abstract

PURPOSE:To produce an alumina cement composition less in swelling of a cured body, excellent in volumetric stability, and having high fluidity, high strength, high corrosion resistance, wear resistance and resistance to spalling. CONSTITUTION:This composition is composed of 100 pts.wt. mixture consisting of 70-50 pts.wt. clinker whose mineral composition is CaO.Al2O3 and CaO.2Al2O3 and chemical component is 25-33wt.% CaO and 75-67wt.% Al2O3 and 30-50 pts.wt. alpha-Al2O3, and 0.8-2.0 pts.wt. additive consisting of 100 pts.wt. carboxylic acids, 40-60 pts.wt. alkali metal carbonate and 10-20 pts.wt. boric acids.

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, more specifically, an alumina cement composition, a refractory aggregate such as magnesia, magnesia spinel, fused alumina, and sintered alumina, and / or explosion proof. In an irregular shaped refractory containing a foaming material such as metallic aluminum as a material, the expansion of the hardened body is less than that of a conventional alumina cement composition, excellent volume stability, high fluidity, and high strength development , An alumina cement composition having characteristics such as corrosion resistance, wear resistance, and spalling resistance.

[0002]

2. Description of the Related Art Conventionally, the following are known as alumina cement compositions. CaO · Al ₂ O ₃ of a specific proportion, 12CaO · 7Al ₂ O _3, and consists of an amorphous, α-Al ₂ O _3, hydro-oxy acids, and alumina cement compositions comprising inorganic carbonate ( Japanese Patent Application No. 45-129562, Japanese Patent Publication No. 49-32921, Japanese Patent Publication No. 5
0-102617, and JP-A-55-121933). Alumina cement containing water-soluble polyacrylic acid and / or methacrylic acid-acrylic acid copolymer and alkali metal carbonate (JP-A-55-75947 and JP-A-5-75947).
5-75948, etc.). Alumina cement containing amorphous with a specific CaO / Al ₂ O ₃ ratio, or CaO · Al ₂ O ₃ , CaO · 2Al ₂ O ₃ , 3CaO · Al ₂ O
_{3, 12CaO · 7Al 2 O 3} , and 11CaO · 7Al ₂ O ₃ · Alumina cement (JP 61-132556 discloses that an amorphous calcium aluminate corresponding to one or more compositions such as CaF ₂ as a main component, JP-A-61-77659 and JP-A-2-175638). Alumina cement containing at least 80% by weight or more of CaO.Al ₂ O ₃ phase clinker and alumina of a specific specific surface area, or alumina cement clinker containing alumina fine powder (JP-A-52) -1119
20 gazette, Japanese Patent Application No. 43-74896 gazette). CaO · 2Al ₂ O ₃ was mainly 12CaO · 7Al ₂ O _3, fine alumina, alumina cement (JP 55-144456 discloses that by blending a sulfonic acid anionic surfactants, JP 55-121
No. 934). Alumina cement consisting of clinker and α-Al ₂ O ₃ having a CaO · Al ₂ O ₃ and CaO · 2Al ₂ O ₃ of a specific ratio (USP four hundred sixteen thousand two hundred ninety-two
3). As a document that describes the basic characteristics of alumina cement mineral composition and types of additives, see "HIGH ALUMINA CEMENT".
AND CONCRETES. TD ROBSON, issued in 1962 ".

Alumina cements described in these patents and documents are intended to improve characteristics such as high strength development, high fire resistance, and high fluidity, but both have advantages and disadvantages, It did not deviate from the category of goods.

[0004] These patents and documents describe that CaO.2Al ₂ O ₃ as a mineral composition of the clinker is not preferable as an alumina cement because it causes hardening delay and lowers strength development. is there.

Further, if the content of Al ₂ O ₃ in the alumina cement is increased to improve the corrosion resistance and the fire resistance, there is a problem that the fluidity is lowered and the curing strength and the dry strength are remarkably lowered. The content ratio of CaO and Al ₂ O ₃ was necessarily limited.

The conventional mineral composition of alumina cement is CaO.Al ₂ O _{3 in} terms of securing fluidity and imparting strength development.
Was limited to those that mainly.

To adjust the curing rate of this CaO.Al ₂ O ₃ , 12CaO ・ 7
A mixture of a fast-setting calcium aluminate such as Al ₂ O ₃ has been proposed (Japanese Patent Publication No.
54-139639, etc.).

However, CaO · 2Al ₂ O ₃ represents the trend of setting retarder and strength development decreases, the 12CaO · 7Al ₂ O ₃ is characterized showing the rapid hardening, even if the hardening adjustment additives, CaO / Al
_The strength development was inferior to the alumina cement mainly composed of ₂ O ₃ .

Due to the above restrictions, although many technologies exist as patents and the like, the composition of alumina cement actually industrialized is limited to that mainly containing CaO.Al ₂ O ₃ For the purpose of adjusting and also for imparting high fire resistance and strength development, it contains 12CaO.7Al ₂ O ₃ , α-Al ₂ O ₃ , and various additives, for the purpose of ensuring high fire resistance. As a result of lowering the CaO content in the clinker, some C
Even if some contain aO.2Al ₂ O ₃ , C
There was no alumina cement that positively utilized aO ・ 2Al ₂ O ₃ .

At present, commercially available alumina cements are trade names "High Alumina Cement Super", "High Alumina Cement Super 2", "High Alumina Cement Super 90" and "High Alumina Cement Super G" manufactured by Denki Kagaku Kogyo Co., Ltd. , "High Alumina Cement Super F",
"High Alumina Cement", "High Alumina Cement-D",
"High Alumina Cement-NEO", "High Alumina Cement # 80", etc., Asahi Glass Industry Co., Ltd. product name "Asahi Alumina Cement No. 1" and "Asahi Fonju", Nippon Cement Co., Ltd. product name "Asano Alumina Cement No. 1" , "Asano Alumina Cement No. 2", Alcoa product name "CA25G", "CA2"
5R "," CA25C "," CA14 ", and" CA15 ", Lafarge product names" Secal 80 "," Secal 71 "," Secal 51 ",
Examples include "Secal 41" and "Symanfonju", trade names "Union No. 1" and "Union HI" manufactured by Union, and "Rumnite" and "Lefcon" manufactured by Lehi.

[0011] These products are all the CaO · Al ₂ O ₃ mainly, depending on the required _{characteristics, 12CaO · 7Al 2 O 3,} α-Al
_It contains ₂ O ₃ and additives, and contains a small amount of CaO · 2Al ₂ O ₃ as a by-product during the production of clinker.

[0012] Further, although some of these products have characteristics such as fluidity, strength development, hardenability, and fire resistance, they are currently used in the refractory field, particularly in the steel field including ironmaking equipment and steelmaking equipment. There is a problem that the required level of the amorphous refractory material required in (1) is insufficient in properties such as fluidity, strength development, fire resistance, and corrosion resistance. For this reason, a method of covering the problems of these alumina cements by taking a combination of refractory aggregates constituting an amorphous refractory is taken.

However, recently, there is a cost advantage,
Amorphous refractory that can dry the cured product in a short time is required, and foaming materials such as aluminum metal aluminum, magnesium metal, zinc metal, barium metal, and aluminum alloy are used to improve explosion resistance during drying. , Organic fibers such as vinylon fibers, colloids such as aluminum lactate, and decomposed gas generating materials such as amide compounds tended to be used as explosion proof materials.

Among these explosion-proof materials, generally used metallic aluminum reacts with alkaline water when an irregular shaped refractory material is poured and kneaded to immediately generate hydrogen gas, and a hardened body is generated by the generation of bubbles. There were problems such as swelling, cracking, and chipping work when building bricks. In particular, metallic aluminum has a problem that the production reaction of hydrogen gas is promoted by the influence of alkaline water generated when kneading an amorphous refractory, and is easily affected by the ambient temperature.

On the other hand, in order to improve the durability of the cured product, it is necessary to densify it, but the densification has caused the contradictory problem of lowering the explosion resistance.

Further, it is necessary to mix a basic aggregate such as magnesia for the purpose of further improving the corrosion resistance against slag and metal, and the hardened material is digested by kneading water to cause cracking or elution from the aggregate. Due to the soluble components that function as a hardening accelerator for alumina cement such as Mg ions, the fluidity during kneading decreases, the pot life during construction shortens, and problems such as hardening in the mixer or hopper occur. It was easy to occur.

Particularly, in a place where high strength development, corrosion resistance, wear resistance, and spalling resistance are required, such as slag line or ladle laying part, steel bath part, and repair in blast furnace. The conventional alumina cement was insufficient in fluidity and strength development for the irregular refractory to be constructed.

Further, in the improvement of durability, conventional alumina cement and known techniques have some advantages and disadvantages, but significant improvement in performance cannot be expected.

In order to solve these problems, the present inventor has conducted various studies, and as a result, a hydraulic clinker consisting of a specific mineral composition and chemical components, α-Al ₂ O ₃ and a specific additive were added. The present invention has been completed with the knowledge that the above problems can be solved by using an alumina cement composition containing the above.

[0020]

A resolution means for] That is, the present invention, the mineral composition is from CaO · Al ₂ O ₃ and CaO · 2Al ₂ O ₃ Prefecture, the chemical components
CaO 25-33 wt%, Al ₂ O ₃ 75-67 wt% clinker 70-50 parts by weight, α-Al ₂ O ₃ 30-50 parts by weight a mixture of 100 parts by weight, carboxylic acids 100 parts by weight Parts, 40 to 60 parts by weight of an alkali metal carbonate, and 0.8 to 2.0 parts by weight of an additive consisting of 10 to 20 parts by weight of boric acids, which is an alumina cement composition.

The present invention will be described in detail below.

The clinker alumina cement used in the present invention consists of CaO · Al ₂ O ₃ and CaO · 2Al ₂ O ₃ as mineral composition, at CaO25~33 wt%, Al ₂ O ₃ from 75 to 67 wt% of It is composed of chemical components. In particular, in the present invention, it is important to satisfy both the mineral composition and the chemical component ratio within this range.

The clinker of the present invention is a high-purity alumina obtained by purifying a natural raw material such as red bauxite by a purification method such as the Bayer process, or Al ₂ O such as bauxite.
₃ sources and CaO sources such as limestone and quick lime are mixed so as to have a predetermined component ratio, and electric furnace, reverberatory furnace, vertical furnace, open hearth furnace,
It is obtained by melting and / or firing with equipment such as a shaft kiln and a rotary kiln.

If we follow the general method for describing the mineral composition of cement and assume that CaO is C and Al ₂ O ₃ is A, the CA-CA ₂ composition can be used at a time to obtain the desired mineral composition of the present invention. There are a method of synthesizing, a method of mixing a CA composition and a CA ₂ composition in a predetermined ratio, and the like.

The content ratio of the mineral composition in the present invention is Cu
It can be analyzed by X-ray diffraction analysis using -Kα ray.

As a method for quantifying the mineral composition by the X-ray diffraction method, there are a diffraction line intensity ratio measuring method, an internal standard method, a Zevine method, an X-ray diffraction peak separation method and the like. In the present invention,
Quantification is possible with either method. The diffraction line intensity ratio measurement method referred to here is a value that relatively expresses the diffraction intensity of each mineral, and the internal standard method is a mixture of an internal standard substance and a sample at a fixed ratio. By utilizing the fact that a linear relationship is obtained between the concentration and the diffraction line intensity ratio, this is a method of preparing and analyzing a calibration curve using a standard sample of known concentration. The Zevine method is a method of quantifying each crystal phase by measuring an average mass absorption coefficient and a diffraction line intensity ratio of a sample and solving an n-th simultaneous equation, and the average mass absorption coefficient is fluorescence X
Quantify the components of the sample by line analysis or chemical analysis,
It can be calculated. In addition to this, it can be quantified by an X-ray diffraction peak separation method, and this method measures from the crystal or glass phase of a sample.

In the present invention, the mineral composition and the vitrification rate can be quantified by any method, but the Zevine method or the diffraction line intensity ratio measuring method is simple and accurate. Is preferably used.

The mineral composition ratio of the hydraulic of the present invention by Zevine method, preferably in the range of CA20~90 parts, CA ₂ 80 to 10 parts by weight, in particular, CA40～80 parts, CA ₂ 6
The range of 0 to 20 parts by weight is more preferable.

The hydraulic mineral composition ratio of the product of the present invention measured by the diffraction line intensity ratio is such that the CA ₂ diffraction intensity ratio CA ₂ / CA to the CA diffraction line is in the range of 0.1 to 10.0 / 1.0. Those produced are preferred. It is more preferable that CA ₂ / CA is in the range of 0.5 to 5.0 / 1.0 from the viewpoint of the balance of fluidity, pot life, curability, and strength development when blended with an amorphous refractory. The mineral composition ratio here means that d of CA is 4.
67 Å, d of CA ₂ is the intensity ratio of the diffraction line of 4.45 Å. C
If the amount of A ₂ is large, the curing in a low temperature atmosphere is significantly delayed and the deframed strength tends to be insufficient. Conversely, if the amount of CA is large, the pH in the kneaded product increases, and in the case of an amorphous refractory containing metal aluminum, The cured product tends to expand during or after construction.

C ₁₂ A ₇ raises the pH in the kneading water and promotes the generation of hydrogen gas from metallic aluminum, so that it is not preferred to be contained in the alumina cement of the present invention.

The preferred pH in the alumina cement slurry is 11.5 or less, and when it is higher than this, the swelling of the hardened body due to the foaming of metallic aluminum becomes large and the volume stability deteriorates when compounded in an amorphous refractory. Cracks tend to occur more easily, and it tends to be difficult to secure fluidity and pot life during construction in a high temperature atmosphere of 30 ° C or higher in summer.

Further, in the case of an irregular shaped refractory containing a basic aggregate such as magnesia, digestion occurs when the pH of the slurry becomes high, and the cured body is cracked or destroyed during drying, which is not preferable. The pH of the slurry is more preferably 11.5 or less after 10 minutes of contact with water.

The pH of this slurry can be measured by an ordinary pH meter using a glass membrane ion electrode, and the pH of the slurry in the present invention is 20 ° C.
In a thermostatic chamber, the measurement was performed by adding 10 g of alumina cement while stirring 100 ml of ion-exchanged water adjusted to 20 ° C. in advance with a stirrer.

The chemical component ratio of the clinker used in the present invention is in the range of CaO 25 to 33% by weight and Al ₂ O ₃ 75 to 67% by weight, and particularly, CaO 27 to 32% by weight and Al ₂ O. _In the range of 373 to 68% by weight, the mineral composition ratio of CA and CA ₂ is preferably in the above range.

The alumina cement composition of the present invention contains, in addition to the intended CA and CA ₂ , α-Al ₂ O ₃ derived from the raw materials.
2CaO ・ Al ₂ O ₃・ SiO ₂ , CaO ・ Ti generated from impurities
Those containing impurities such as O ₂ and 4CaO ・ Al ₂ O ₃・ Fe ₂ O ₃ can also be used, but it is preferable that the impurities in the alumina cement be small, and SiO ₂ is 0.5% by weight or less, TiO ₂
Is 0.5% by weight or less, and Fe ₂ O ₃ is preferably 0.5% by weight or less. In particular, chemical components other than Igros, CaO, and Al ₂ O ₃ are less than 0.1% by weight and less in each component. Those are preferable. If these impurities are large, the volume change of the hardened body at high temperature becomes large when used for irregular refractory,
In addition, the corrosion resistance to slag and the like decreases, which is not preferable.

Further, a small amount of unreacted CaO or Al ₂ O ₃ may be contained within a range that does not impair the characteristics of the alumina cement. 2% by weight or less of unreacted CaO and unreacted A
L ₂ O ₃ is preferably about 10 wt% or less, more preferably 1.0 wt% or less for CaO and 5.0 wt% for Al ₂ O ₃ .

When unreacted raw material is present in the clinker,
Ca ions elute during kneading or exist as a filler, which deteriorates fluidity, shortens pot life, accelerates hardening, and reduces strength development and high temperatures. Volume stability tends to deteriorate.

If the clinker is out of the range of these mineral compositions and chemical components, the hardness of the amorphous refractory containing the explosion-proof material such as metallic aluminum and the timing of foaming do not match, and the cured product easily expands, In the case of an irregular shaped refractory containing a basic aggregate such as magnesia, it is difficult to secure fluidity and pot life, and cracks easily occur due to digestion of the aggregate during drying.

When the product of the present invention is manufactured by the melting method,
It is important that the Al ₂ O ₃ / CaO molar ratio is in the range of 2.0 to 6.0, and the mineral composition obtained after melting is the CA-CA ₂ composition. In the melting method, the CA and CA ₂ mineral compositions are 21.5-35.4% by weight of CaO because the composition ratio of is determined thermodynamically.
In, it is preferable that Al ₂ O ₃ is blended raw material to be 78.5 to 64.6 wt%, CaO is at 25.0 to 33.0 wt%, Al ₂ O ₃
It is more preferable to mix the raw materials so that the component ratio is 75.0 to 67.0% by weight.

It is preferable that the blended raw material is melted at a high temperature of 1,500 ° C. or higher, more preferably 1,700 ° C. or higher by a melting device such as an electric furnace or a flat furnace, and then the clinker is cooled by contacting with high pressure air or water. .

In the present invention, a composition consisting of CA and CA ₂ is synthesized at one time, or CA and CA ₂ are mixed at a predetermined mixing ratio so that the desired mineral composition is obtained. Clinkers composed of different CA and CA ₂ may be combined so as to have a desired mineral composition ratio.

The clinker may be mixed after crushing the clinker with each other, or may be crushed, or may be crushed, and the means for obtaining the desired mineral composition ratio is not particularly limited. Absent.

As the clinker crusher, a crusher which is usually used for finely pulverizing powder mass can be used. For example, a roller mill, a jet mill, a tube mill, a ball mill, a vibration mill or the like can be used.

Since the Blaine specific surface area of the clinker is related to the important properties of the alumina cement, that is, the fluidity, the hardenability, and the strength development, it is an important control point for obtaining the target properties, and it is ground. the particle size of the clinker, a specific surface area by Blaine method, preferably at least 3,000 cm ² / g, more preferably at least 4,000cm ² / g, 4,500~8,000
cm ² / g is most preferred. If it is less than 3,000 cm ² / g, the strength may decrease and the fluidity may decrease.

The average particle size is preferably finely pulverized to 10 μm or less because of excellent fluidity and pot life at high temperature, and more preferably 1 to 7 μm. The average particle diameter referred to here is a value of the particle size measurement result by a commonly used particle size distribution measuring instrument such as a laser diffraction method, a laser scattering method, or a sedimentation balance method, and is a 50% average diameter.

[0046] The α-Al ₂ O ₃ used in the present invention is a purified alumina obtained by calcining a highly purified treated aluminum hydroxide by the buyer processes like rotary kiln, the Al ₂ O ₃ 90 It is a high-purity alumina containing at least wt%. Generally, it is called high-purity alumina, Bayer alumina, easy-sintering alumina, or light-burning alumina. In the present invention, α-Al ₂ O ₃ is, when the alumina cement composition of the present invention is used for an amorphous refractory,
It is effective for imparting high fire resistance, high temperature strength development, and volume stability. Moreover, the characteristics of the alumina cement composition vary greatly depending on the type of α-Al ₂ O ₃ to be blended, so the selection of α-Al ₂ O ₃ is important.

[0047] Particularly, in the present invention, by interaction with the clinker to be combined, which can exhibit no characteristic first conventional products, combined alpha-Al ₂ O
₃ , the primary particle size before crushing is the average particle size (Dp50), 40 ~ 1
It is preferable that the firing degree is about 00 μ and the firing degree is in the range of 0.5 to 100 m ² / g in terms of specific surface area by the BET method. Normal,
This primary particle size is related to the precipitation rate of aluminum hydroxide in the Bayer process. When the precipitation rate is slow, a large size is obtained, and conversely, a small size is obtained. The degree of calcination indicates that the larger the specific surface area, the lighter the type of alumina, and when used at high temperatures, it has excellent sinterability, but also has the drawback of large shrinkage. In the present invention, the primary particle diameter of α-Al ₂ O ₃ is 30 to 60 μ, and the degree of calcination of alumina is preferably a specific surface area of 2 to 10 m ² / g by the BET method, 40 to 50 μ, and 6 More preferably, it is in the range of 8 m ² / g. The degree of calcination indicates that the larger the specific surface area, the lighter the type of alumina, and when used at high temperatures, it has excellent sinterability, but also has the drawback of large shrinkage. When the specific surface area is large, the fluidity of the alumina cement composition is lowered, and when it is small, the fluidity tends to be improved. Further, when the specific surface area is large, when mixed with an amorphous refractory, the sinterability at high temperature is improved, but oversintering tends to reduce spalling resistance and increase shrinkage. A mixture of alumina having a small specific surface area shows an opposite tendency. For this reason, the selection of alumina to be blended in the present invention greatly affects the properties of the alumina cement composition, and therefore should be carefully performed, and should be appropriately determined depending on the required quality when blended in an amorphous refractory. In terms of fluidity, curability, strength development, shrinkage, and spalling resistance, the primary particle diameter is 30 to 60 μ, and the degree of calcination is ² to 10 m ^{2 in} terms of specific surface area by the BET method. The use of / g alumina is preferred.

The purity of α-Al ₂ O ₃ is Al ₂ O ₃ 9 in the case of alumina produced by a usual Bayer process.
It is possible to secure a purity of about 8% by weight or more. In the present invention, although the purity of Al ₂ O ₃ has never been high,
It suffices if it is at least wt%. When used in the present invention,
In addition to Al ₂ O ₃ purity, the amount of Na ₂ O as an impurity is a problem, and when the amount of Na ₂ O is large, the alumina cement composition has reduced fluidity, reduced fire resistance, and high temperature. The amount of Na ₂ O is preferably small, preferably 0.5 wt% or less, and more preferably 0.35 wt% or less low sodium type.

[0049] In the present invention, either blended with the clinker the α-Al ₂ O _3, mixed grinding by a grinder, alpha-Al ₂ O
It is also possible to pulverize ₃ alone to a particle size corresponding to alumina cement and then mix it with a clinker pulverized product. α-Al ₂ O
_{When 3} is pulverized alone, it is preferable to pulverize it to a Dp50 of about 1 to 10 μm. In the present invention, it is better to mix and grind α-Al ₂ O ₃ with a clinker, because it is more compatible with the cement particles, and because it is uniformly mixed in the alumina cement composition, when used for an amorphous refractory, it hardens. The body tissue becomes uniform and the corrosion resistance tends to be improved.

Clinker and α-Al₂O₃The mixing ratio of
70 to 50 parts by weight of linker, α-Al₂O₃30-50 parts by weight
And 65 to 55 parts by weight of the clinker, α-Al₂O₃35
It is preferably about 45 parts by weight. α-Al₂O₃Increase the compounding amount of
Then, the fire resistance and the sintering strength at high temperature increase, but the curing strength
Degree and dry strength tend to decrease, and fluidity also tends to decrease.
Particularly preferably, the combination with the component composition of the clinker to be blended
There is a tradeoff, but α-Al ₂O₃Component ratio at the time of blending
Is CaO 25-15% by weight, Al₂O₃75-85% by weight
It is important to formulate it like this. In particular, in the present invention
Is CaO22-16% by weight, Al₂O₃78-84% by weight, and the balance
What was blended to the range of Igros and impurities,
It is preferable because it has good fluidity and high strength.
Especially used for amorphous refractories containing magnesia aggregate
When it does, α-Al in the alumina cement composition₂O₃Many
Cousin reacts with magnesia at high temperature,
The tendency of volume expansion in the process of
Therefore, α-Al in alumina cement₂O₃Exceeds 80% by weight
It is necessary to add a large amount of
It is not preferable depending on the type and amount of the compounded aggregate.
Amorphous refractories using alumina cement composition
Depending on the target properties of the
Instead, it is possible to fluidly change the blending ratio.

The carboxylic acids used in the present invention are carboxylic acids or alkali salts thereof. Here, the carboxylic acid is an oxycarboxylic acid, and specific examples thereof include citric acid, tartaric acid, succinic acid, lactic acid, and gluconic acid. Examples of the alkali salt of carboxylic acid include sodium salt, potassium salt, calcium salt and the like. Among these, it is preferable to use citric acid or an alkali salt thereof, especially sodium citrate or potassium citrate. The particle size of carboxylic acids, when mixed with cement,
The finer the particle size, the more preferable it is, so that it is easily dissolved in water, preferably 100 mesh or less, particularly preferably 200 mesh or less. The purity of the carboxylic acids is not particularly limited, but it is possible to use carboxylic acids that are currently industrially refined, and the purity of the target carboxylic acids is about 80% by weight or more. Is preferred. Among them, citric acid or its salt containing less than 0.05% by weight of sulfate as an impurity, or 20 ° C
It is more preferable to use citric acid or a salt thereof in which the pH of the 1% by weight aqueous solution is 7 to 10 because the pot life is excellent.

As the alkali metal carbonate used in the present invention, any of inorganic carbonates can be used.
Sodium carbonate, potassium carbonate, sodium hydrogen carbonate,
And the use of alkali metal carbonates such as potassium hydrogen carbonate are preferred, and any of their hydrated salts and anhydrous salts can be used. Of these, sodium carbonate is preferably used, and sodium carbonate defined by JIS K 1201, JIS K 8624, and JIS K 8625 can be used. The particle size of the alkali metal carbonate is preferably as fine as possible so that it can be easily dissolved in water when mixed with cement, more preferably 100 mesh or less, and particularly preferably 200 mesh or less. The purity of the alkali metal carbonate is not particularly limited, but currently industrially refined alkali metal carbonate can be used, and the purity of the desired carbonate is 80
It is preferable to use one having a weight percentage of about 10% or more.

The boric acid used in the present invention is boric acid or its alkali salt. Here, boric acid is also known as boric acid, orthoboric acid, or orthoboric acid,
It is represented by H ₃ BO ₄ and contains pyroboric acid, tetraboric acid, and metaboric acid. The method for producing boric acid is not particularly limited, but it is usually obtained by adding sulfuric acid to a raw ore of boric acid for thermal decomposition, liberating boric acid, separating and extracting, and then purifying. As an alkaline salt of boric acid,
Examples thereof include sodium salt, potassium salt, and calcium salt. Among them, it is preferable to use sodium salt or potassium salt, and any of the hydrated compound and anhydrous compound thereof can be used. The particle size of boric acids is preferably as small as possible so as to be easily dissolved in water when mixed with cement. Also,
The purity of boric acid is not particularly limited, but currently industrially purified boric acid can be used, and boric acid having a BO ₄ content of 80% by weight or more can be used. preferable.

In the present invention, the above-mentioned carboxylic acids, alkali metal carbonates, and boric acids are added as additives.

The blending ratio of each component in the additive should be appropriately selected depending on the alumina cement composition.
From the aspect of ensuring the balance of fluidity, curability, and strength development, 100 parts by weight of carboxylic acids, 40 to 60 parts by weight of alkali metal carbonate, and 10 to 20 parts by weight of boric acid, 100 parts by weight of carboxylic acids. , 45 to 55 parts by weight of alkali metal carbonate, and 13 to 18 parts by weight of boric acid are preferable.

Particularly, as the carboxylic acid, citric acid and / or sodium citrate, as the alkali metal carbonate, sodium carbonate and / or potassium carbonate, and as the boric acid, sodium borate and / or potassium borate are blended. What was done, as an alumina cement composition,
It is preferable because it is excellent in fluidity and pot life and has good strength development.

These additives are clinker and α-Al ₂ O ₃
Based on 100 parts by weight of the mixture consisting of
It is preferable to mix it in an amount of 0.8 to 2.0 parts by weight, and it is particularly preferable to use an additive in the range of 1.0 to 1.6 parts by weight because the curing delay is small and high fluidity can be secured.

The method of blending the additives in the present invention is not particularly limited, and each additive is blended in a predetermined ratio and crushed in advance with a clinker, a V-type blender, a corn blender, and a Nauta mixer. , Use a mixer such as a pan-type mixer and an omni mixer, or mix them in a clinker at a predetermined ratio, and then mix and pulverize with a pulverizer such as a vibration mill, tube mill, ball mill, and roller mill. It is possible.

Sugars such as dextrin and starch are used as curing retardants, alkali hydroxides such as calcium hydroxide, sodium hydroxide, potassium hydroxide and lithium hydroxide, lithium chloride, lithium carbonate and citric acid. If necessary, a lithium compound such as lithium acid can be added as a curing accelerator. Since the alumina cement composition of the present invention tends to delay the curing under low temperature conditions due to the inclusion of CA ₂ , it is preferable to add a lithium compound as a curing accelerator.

Examples of the lithium compound used in the present invention include lithium hydroxide, lithium chloride, lithium carbonate, lithium citrate, lithium nitrate, and lithium fluoride. Among these lithium compounds, lithium carbonate is most preferable because it is excellent in the curing acceleration effect and handling.

The amount of these hardening accelerators added to the alumina cement composition of the present invention depends on the hardening characteristics of the intended amorphous refractory, but it is usually an alumina cement composition.
The curing accelerator is preferably 2.0 parts by weight or less, more preferably 0.001 to 1.0 part by weight, based on 100 parts by weight. The addition of the curing accelerator in the present invention, the curing of the amorphous refractory using the alumina cement composition of the present invention, generally, it is necessary to add when the time exceeds 24 hours, the working temperature
It is preferably added in the case of 25 ° C or lower.

The alumina cement composition of the present invention has an IC
P, ICPA, GC-MS, C 13 -NMR, HPLC,
The type and amount ratio can be specified by instrumental analysis such as FT-IR, chelate analysis, activation analysis and the like.

The refractory aggregate referred to in the present invention can be a refractory aggregate which is usually used for an irregular shaped refractory,
Specifically, fused magnesia, fused magnesia, sintered magnesia, natural magnesia, magnesia such as easy-sintered magnesia, magnesia such as lightly burned magnesia, magnesia spinel such as fused spinel and sintered spinel, fused alumina, sintered alumina, Alumina such as easily sintered alumina and light burned alumina, ultrafine powder such as silica fume and colloidal silica,
Fused silica, calcined mullite, chromium oxide, bauxite, andalusite, sillimanite, chamotte, silica stone, loastone, clay, zircon, zirconia, dolomite, perlite, vermiculite, brick kudzu, pottery kudzu,
Silicon nitride, boron nitride, silicon carbide, and iron silicon nitride can be used. Particularly in the irregular shaped refractory used in the present invention, in terms of corrosion resistance, durability, and fire resistance,
It is preferable to use one or more kinds of refractory aggregates selected from magnesia, magnesia spinel, alumina, and ultrafine powder.

Here, magnesia means Mg (OH) ₂ extracted from seawater by the seawater method, magnesia carbonate, and natural MgO.
Sintered MgO clinker and / or M obtained by firing (magnesite) or natural magsia carbonate in a rotary kiln, etc.
Electrofused MgO clinker obtained by melting gO clinker in an electric furnace etc. is crushed and sieved to a specified size, and the purity of MgO as 80% by weight or more is amorphous fire resistance. It is preferable because it is excellent in corrosion resistance when used as a material, and those containing few impurities such as SiO ₂ and TiO ₂ are preferable.

The magnesia spinel referred to in the present invention is a mixture of MgO source such as magnesium hydroxide or calcined magnesia and Al ₂ O ₃ source such as aluminum hydroxide or calcined alumina in a predetermined ratio. Then, using a calcining device such as a rotary kiln, a magnesia spinel clinker is obtained by reacting and sintering at a temperature of about 1,800 to 1,900 ° C, and / or molten magnesia spinel melted by a melting device such as an electric furnace. , Which was crushed to a predetermined size and sieved.

The alumina referred to in the present invention is obtained by sintering an Al ₂ O ₃ source such as aluminum hydroxide or calcined alumina by a firing device such as a rotary kiln or a melting device such as an electric furnace.
The molten material was crushed to a predetermined size and sieved, and the mineral composition was α-Al ₂ O ₃ or β-Al ₂ O ₃
Is in the form of aluminum oxide, such as
Sintered alumina, calcined alumina, and a what is called the easy sintering alumina or the like, usually, the use of α-Al ₂ O ₃ containing Al ₂ O ₃ 90 wt% or more is most preferred.

The ultrafine powder referred to in the present invention is a refractory fine powder in which 80% by weight or more of particles having a particle size of 10 μ or less are contained, and examples thereof include silica fume, colloidal silica, easily sinterable alumina, amorphous silica and zircon. Inorganic fine powder such as silicon carbide, silicon nitride, chromium oxide, and titanium oxide. Particularly in the present invention, silica fume, colloidal silica,
Also, ultra-fine powder of easy-sinterable alumina is preferable, and the average particle diameter of which is 1 μ or less and the specific surface area of which is 10 m ² / g or more by the BET method can secure fluidity when compounded into an amorphous refractory. It is preferable because it has high strength. In particular, activated fine particles such as silica fume that have an ion-adsorptive functional group on the particle surface improve the filling property and sinter in the case of amorphous refractory containing easily digestible aggregate such as magnesia. In addition to improving the properties, it is preferably used in combination from the viewpoint of preventing digestion of aggregate.

When the alumina cement composition of the present invention is used in an amorphous refractory, the blending ratio of the constituent raw materials of the amorphous refractory should be appropriately determined depending on the intended construction site. Cement composition 0.5-50
It is preferable that the content of the refractory aggregate is 99.5 to 50 parts by weight based on parts by weight. In particular, it is preferable to mix 2 to 15 parts by weight of the alumina cement composition and 98 to 85 parts by weight of the fire-resistant aggregate from the viewpoint of corrosion resistance and strength development. As the fire-resistant aggregate, from the viewpoint of suppressing slag penetration, magnesia and alumina A combination or a combination of magnesia spinel and alumina is preferable.
Particularly preferred ranges are 2 to 15 parts by weight of an alumina cement composition, 5 to 20 parts by weight of magnesia having a particle size of 1 mm or less, and the balance of fused alumina and / or sintered alumina having a particle size of 1 to 10 mm.
And 2 to 15 parts by weight of alumina cement composition, particle size 1
5 to 20 parts by weight of magnesia spinel with a diameter of 1 mm or less, and the balance mainly composed of fused alumina and / or sintered alumina having a particle size of 1 to 10 mm is preferable in places where corrosion resistance is required such as ladle materials. .

The method for producing an irregular refractory material using the alumina cement composition of the present invention is not particularly specified, but according to the ordinary method for producing an irregular refractory material, each constituent raw material is mixed in a predetermined ratio. Blended to become a V type blender,
Corn blender, nauta mixer, pan mixer,
It is also possible to perform uniform mixing using a mixer such as an omni mixer, or to directly weigh into the kneading machine when performing kneading at a predetermined ratio.

Further, the amorphous refractory using the alumina cement composition of the present invention includes metallic aluminum or aluminum which reacts with alkaline water to generate hydrogen gas and generate bubbles for the purpose of preventing explosion when the cured product is dried. Metal magnesium etc.,
Organic fibers such as vinylon fiber, polypropylene fiber, and vinyl chloride fiber that form pores when heated, basic colloids such as aluminum lactate that form pores by shrinking when heated, nitrogen gas generating and decomposing fibers, and quinone and glucan. An explosion-proof material such as humic acids having a structure can be blended as necessary.

Among these explosion-proof materials, it is common to use metallic aluminum and organic fibers. However, in the case of an irregular shaped refractory containing metallic aluminum, the cured body expands due to the formation of bubbles due to the generation of hydrogen gas. , There is a risk of explosion due to hydrogen gas generated. In particular, the expansion of the cured product is a problem, and if the generation timing of hydrogen gas is late, cracks may occur or abnormal expansion may occur. Organic fibers are not accompanied by chemical reactions such as hydrogen gas generation, but when added in large amounts to improve explosion resistance, the fluidity decreases, so if you try to secure a certain amount of fluidity, the amount of added water increases, There are problems such as a decrease in strength, a large shrinkage at high temperature, and a porous cured product, which lowers corrosion resistance. Further, it is important to select a material for the basic colloid, and it is not compatible with the alumina cement-based binder, and there is a problem that the explosion blast resistance effect becomes insufficient. Since these explosion-proof materials may cover each other's defects and promote their effects, they can be used in combination. In particular, the alumina cement composition of the present invention can suppress volume expansion after construction of an amorphous refractory compounded with metallic aluminum, so a place where drying for a short time is required or a place where the burner frame is directly exposed to a dry place. It can be installed on.

The metallic aluminum used in the present invention is
Among metal aluminum, gas atomizing method, rotary atomizing method, or by a manufacturing method such as a vacuum atomizing method, which is an atomized pure aluminum powder or aluminum alloy powder, which is called atomized aluminum, with a particle size of 500μ or less. Those having excellent foaming timing and explosion-preventing effect are preferable. Generally, it is necessary to appropriately select the particle size, the addition amount, and the brand according to the target characteristics of the amorphous refractory, but usually, 0.1 to 1.
0% can be added, and it is preferable to add about 0.2 to 0.6%.
Aluminum alloy powder includes alloy powder containing silica and magnesium. Leafing aluminum and non-leafing aluminum, which are called flake aluminum in which the surface of metallic aluminum particles is not oxidized, are amorphous refractories because when they are kneaded with alumina cement, they rapidly start foaming with alkaline water. Is not preferable. When the slurry pH of the alumina cement to be combined is high alkali, the foaming of metallic aluminum starts in a short time after construction, and when the pH is low, the generation timing of hydrogen gas tends to be relatively late.

In order to use the alumina cement composition of the present invention, it is important that the cohesive strength of the kneaded amorphous refractory is expressed and the generation timing of hydrogen gas is higher than the generation timing of hydrogen gas. If it is slow, the cured product will largely expand, and conversely, if the cohesive strength develops too early, problems such as cracks occurring in the cured product due to the generation of hydrogen gas will occur.
The balance between the development of the cohesive strength and the generation timing of hydrogen gas is easily influenced by the brand and particle size of the metal aluminum to be blended, the addition amount, and the working temperature, and it is necessary to appropriately determine the optimum blending composition. No matter how the conditions are set with conventional alumina cement compositions, it is difficult to secure fluidity at high temperatures and pot life in amorphous refractory containing magnesia aggregate, and metal aluminum is added. In the case of the irregular shaped refractory, it was not possible to prevent volume expansion and crack generation after casting.

Since the alumina cement composition of the present invention tends to be delayed in hardening during low-temperature construction, a hardening accelerator may be added during the production of an irregular shaped refractory, and the explosion resistance and the metallic aluminum may be improved. Utilizing the hydration exothermic reaction of
It is preferable to accelerate the hydraulic reaction of the alumina cement.

[0075]

EXAMPLES The present invention will be further described below based on examples.

Example 1 A clinker was produced by calcining a raw material prepared by mixing calcined alumina as an Al ₂ O ₃ source and limestone powder as a CaO source at a predetermined ratio and then allowing it to cool to a temperature of 1,400 to 1,600 ° C. With this clinker and α-Al ₂ O ₃ , the amount of CaO in the alumina cement composition is about
Blend it to be 18% by weight and use a ball mill to
After crushing to an average particle size of 10μ or less, 100 parts by weight of this mixture and sodium citrate 1 which is additive a
An alumina cement composition was prepared by blending 00 parts by weight, 1.5 parts by weight of an additive b, 50 parts by weight of sodium carbonate, and 15 parts by weight of an additive c, 15 parts by weight of borax.
10 parts by weight of this alumina cement composition and sintered alumina
80 parts by weight, 10 parts by weight of sintered magnesia, silica fume
1.0 part by weight, atomized aluminum 0.5 part by weight, and water 6.5 parts by weight were added and kneaded for 3 minutes with a mortar mixer to obtain an amorphous refractory material. The following items were measured for this amorphous refractory. The results are shown in Table 1. The kneading and curing of the materials were performed in a thermostatic chamber at 30 ° C.

<Materials used> Al ₂ O ₃ source: calcined alumina, specific surface area 5 m ² / g CaO source: limestone powder, 100 mesh, CaCO ₃ purity 98% Clinker A: CaO 20 wt%, Al ₂ O ₃ 80 % By weight, CA ₂ /
CA = 15.0 Clinker B: CaO 25% by weight, Al ₂ O ₃ 75% by weight, CA ₂ /
CA = 1.7 Clinker C: 28% by weight of CaO, 72% by weight of Al ₂ O ₃ , CA ₂ /
CA = 1.5 Clinker D: CaO 30% by weight, Al ₂ O ₃ 70% by weight, CA ₂ /
CA = 1.2 Clinker E: 33% by weight of CaO, 67% by weight of Al ₂ O ₃ , CA ₂ /
CA = 0.5 Clinker F: 35% by weight of CaO, 65% by weight of Al ₂ O ₃ , CA ₂ /
CA = 0.1 Clinker G: 36% by weight of CaO, 74% by weight of Al ₂ O ₃ , C ₁₂ A ₇
/CA=1.0 Clinker H: CaO 30% by weight, Al ₂ O ₃ 70% by weight, C ₁₂ A ₇
/ CA ₂ = 0.3 clinker I: CaO 25% by weight, Al ₂ O ₃ 75% by weight, CA ₂ /
CA = 4 Clinker J: CaO 30% by weight, Al ₂ O ₃ 70% by weight, CA ₂ /
CA = 0.5 Clinker K: 33% by weight of CaO, 67% by weight of Al ₂ O ₃ , CA ₂ /
CA = 0.15 α-Al ₂ O ₃ : specific surface area 6 m ² / g, average particle size 50 μ Additive a: sodium citrate, a reagent manufactured by Ishizu Pharmaceutical Co., Ltd. additive b: sodium carbonate, reagent manufactured by Ishizu Pharmaceutical Co., Ltd. c: Borax, reagent made by Ishizu Pharmaceutical Co., Ltd. Sintered alumina: product name “Aluminite A37” made by Naigai Ceramic Co., Ltd. Mixture of 35 parts by weight of 5 to 1 mm product and 45 parts by weight of 1 mm Sintered magnesia: Ube Chemical Co., Ltd. , Under 200 mesh Silica fume: Elchem Co., Ltd. atomized aluminum: Toyo Aluminum Co., Ltd. product name “AC100
3 ”Commercial product S: Alumina cement product name“ High Alumina Cement Super ”by Denki Kagaku Kogyo Co., Ltd. Commercial product S-2: Alumina cement product name“ High Alumina Cement Super 2 ”by Denki Kagaku Kogyo

<Methods for measuring physical properties> Chemical components: CaO and Al ₂ O ₃ are analyzed according to JIS R 2522 Mineral composition: X-ray diffraction analyzer “RADIIB” manufactured by Rigaku Corporation
Diffraction intensity ratio by d, CA = 4.67Å, CA ₂ = 4.45Å, C ₁₂ A ₇ = 4.89
Å, α-Al ₂ O ₃ = 2.55 Diffraction line intensity Average particle size: Shimadzu's laser diffraction particle size analyzer “SALD1000” was used Slurry pH: Normal p using a glass membrane ion electrode
In the constant temperature room at 20 ℃, use the H meter to measure 20
100 ml of deionized water adjusted to ℃ and alumina cement 10
Weigh g and measure the pH value when stirring with a stirrer for 10 minutes Flowability: After kneading for 3 minutes, using the kneaded product that has been left for 30 minutes, the spread diameter after 15 taps with a flow table is JIS Measured according to R 2521 Pot life: The time it took for the formed amorphous refractory to be transferred to a plastic bag and lose its fluidity Curing time: 500 g of the irregular refractory prepared was transferred to a polybeaker and platinum With a resistance thermometer and a dot recorder,
Time from water injection to peak of heat of hydration Curing strength: The prepared irregular refractory was struck while stamping with a piercing rod on a 4 × 4 × 16 cm formwork, and the surface was leveled with a cement knife. After that, the compressive strength after curing for 24 hours is measured with a hydraulic pressure measuring instrument. Drying strength: The cured product specimen after curing is dried at 110 ° C for 24 hours, allowed to cool to room temperature, and the compressive strength is measured with a hydraulic measuring instrument. Baking strength: The dried cured sample is put in a silicon knit electric furnace and heated to 800 ° C at a heating rate of 5 ° C / min, and then 2
Hold for a while, let cool to room temperature, and measure the compressive strength with a hydraulic pressure measuring instrument. Swelling of cured material: Transfer the kneaded material to a beaker of φ90 x 122 mm, smooth the upper surface, and leave it for 24 hours from the top of the beaker. Measure the swelling thickness of the product Explosion resistance: After pouring into a cylindrical mold of φ55 × H50mm,
The cured product, which has been cured for 24 hours at a specified temperature, is placed in a siliconnit electric furnace heated to 1,000 ° C and observed for explosion.

[0079]

[Table 1]

As shown in Table 1, the amorphous refractory containing the alumina cement composition of the present invention can secure the fluidity and the pot life as compared with the comparative example, and obtain an appropriate curing time and high strength. The bulging of the construction body was small.

Example 2 Example 1 was repeated except that Clinker C was used and the amounts of clinker and α-Al ₂ O ₃ were changed as shown in Table 2. The results are also shown in Table 2.

[0082]

[Table 2]

Example 3 100 parts by weight of a mixture of 60 parts by weight of clinker D and 40 parts by weight of α-Al ₂ O ₃ was used, except that 1.5 parts by weight of the additive compounded as shown in Table 3 was added. The procedure was as in Example 1. The results are also shown in Table 3.

[0084]

[Table 3]

Example 4 Example 4 was repeated except that the kind of the additive was changed as shown in Table 4. The results are also shown in Table 4.

<Materials to be used> Additive d: citric acid, a reagent manufactured by Ishizu Pharmaceutical Co., Ltd. additive e: tartaric acid, a reagent manufactured by Ishizu Pharmaceutical Co., Ltd. additive f: sodium tartrate, a reagent manufactured by Ishizu Pharmaceutical Co., Ltd. additive g: gluconic acid, Ishizu Pharmaceutical Reagent Additive h: Sodium Gluconate, Ishizu Pharmaceutical Reagent Additive i: Potassium Carbonate, Ishizu Pharmaceutical Reagent Additive j: Boric Acid, Ishizu Pharmaceutical Reagent Additive k: Potassium Borate, Ishizu Pharmaceutical reagent

[0087]

[Table 4]

Example 5 Table 5 shows the amounts of additives consisting of 100 parts by weight of additive a sodium citrate, 50 parts by weight of additive b sodium carbonate, and 15 parts by weight of additive c borax. The same procedure as in Example 3 was performed except that the changes were as shown. The results are also shown in Table 5.

[0089]

[Table 5]

Example 6 100 parts by weight of a mixture of 65 parts by weight of clinker C and 35 parts by weight of α-Al ₂ O ₃ and 1 part of sodium citrate as additive a
An alumina cement composition was prepared by blending 00 parts by weight, 50 parts by weight of sodium carbonate as an additive b, and 1.2 parts by weight of an additive consisting of 15 parts by weight of a borax as an additive c. As in Example 1, except that the lithium compound was blended and the ambient temperature was 10 ° C. The results are also shown in Table 6.

<Materials used> Lithium compound a: Lithium carbonate, reagent manufactured by Ishizu Pharmaceutical Co., Ltd. Lithium compound b: Lithium chloride, reagent manufactured by Ishizu Pharmaceutical Co., Ltd. Lithium compound C: Lithium hydroxide, reagent manufactured by Ishizu Pharmaceutical Co., Ltd. Lithium compound D: Citric acid Lithium, Ishizu Pharmaceutical Co., Ltd. reagent

[0092]

[Table 6]

As shown in Table 6, the amorphous refractory containing the alumina cement composition of the present invention can secure the fluidity and the pot life, obtain an appropriate curing time and high strength, and There was little blistering, and there was little delay in curing at low temperatures.

[0094]

The alumina cement composition of the present invention comprises an alumina cement composition, a refractory aggregate such as magnesia, sugnesia spinel, fused alumina, and sintered alumina, and / or metallic aluminum as an explosion proof material. In an irregular shaped refractory containing a foaming material such as, the expansion of the cured body is less than that of the conventional alumina cement composition, excellent in volume stability, high fluidity, high strength development, high corrosion resistance, It has features such as abrasion resistance and spalling resistance, starting in the steel field centering on blast furnaces and electric furnaces where alumina cement is used, incinerators, cement kilns, and chemical plants, Further, it can be used as various refractory materials and food materials.

In the field of refractory materials, alumina cement has been used up to now. Irregular shaped refractory materials such as spraying materials, press-fitting materials, and gutter materials used around furnaces such as blast furnaces and electric furnaces, and mixed pig car. , Unshaped refractory used for iron making equipment and steel making equipment such as steel, topping, tundish, ladle, lance material, soaking furnace, heating furnace, and coke oven, and equipment related to cement kiln. By using basic aggregates such as converters and special refining pots,
With the conventional amorphous refractory compounded with alumina cement, it is possible to make the site difficult to be constructed due to problems such as fluidity during construction, volume stability after hardening, and explosion proof.

When used for an irregular shaped refractory material containing a foaming material such as metallic aluminum, the cured product has little swelling due to foaming and has not only excellent volume stability but also basic aggregate such as magnesia. In that case, high liquidity can be secured,
High strength can be obtained.

For this reason, such as a blast furnace ladle material and an electric furnace ladle material, where volume stability and explosion resistance when the hardened material is dried are important as in the case of combining an irregular refractory and a fixed brick. When mixed with irregular shaped refractory materials such as pot material, tundish, and gutter material, it provides construction stability and high durability not available in conventional products.

Further, it can be used not only in the refractory field but also as a lining or a corrosion resistant material for a chemical plant which requires high strength development, high fluidity, high corrosion resistance and abrasion resistance.
Since the lining material using the product of the present invention can obtain high fire resistance, high strength development, wear resistance, and high corrosion resistance, it can be used not only as a food material such as petroleum refining equipment, a wear resistant material, and a fire resistant material. Without hydraulic ceramics, catalyst support,
It can also be used as a corrosion-resistant building material.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C04B 22:10 22:08) Z 103: 60 111: 20

Claims (1)

[Claims] 1. A mineral composition consists CaO · Al ₂ O ₃ and CaO · 2Al ₂ O ₃ Prefecture, a chemical component is CaO25~33 wt%, Al ₂ O ₃ 75~67
70 to 50 parts by weight of clinker, which is a weight percent, and α-Al ₂ O ₃ 30
100 parts by weight of a mixture consisting of ~ 50 parts by weight, 100 parts by weight of carboxylic acids, 40 to 60 parts by weight of alkali metal carbonate, and 0.8 to 2.0 parts by weight of an additive consisting of 10 to 20 parts by weight of boric acid. An alumina cement composition comprising: