JPH10101441A - Composition for cast refractory and method for forming furnace wall using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition for castable refractory capable of providing dense executed product of refractory by adoption of a specific composition containing refractory aggregate, refractory powder, aluminum-silicon alloy powder, organic fiber and dispersing agent, not causing explosion by rapidly drying and free from danger of ignition to generated H2 gas. SOLUTION: This castable composition comprises refractory aggregate, refractory powder, aluminum-silicon alloy powder, an organic fiber and a dispersing agent. The composition contains the aluminumsilicon alloy powder and the organic fiber in amounts of respectively 0.002-1 pts.wt. and 0.02-0.5 pts.wt. based on 100 pts.wt. total amount of the refractory aggregate and refractory powder. A furnace wall is formed as follows by using the composition. Monolithic refractory body obtained by mixing the composition with a prescribed amount of water is executed in a place forming a desired furnace wall by casting and the surface of the executed refractory is heated and dried at a temperature raising rate of >=50 deg.C/hr until surface temperature of refractory becomes >=500 deg.C (usually >=1000 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pouring method which prevents explosion during heating and drying used for lining materials of various furnaces, lining materials of refining vessels such as ladles, linings for refining, and lining materials of gutters. The present invention relates to a refractory composition and a method for forming a furnace wall using the same.

[0002]

2. Description of the Related Art Amorphous refractories require less labor for construction, can be constructed in any shape, and have improved performance as refractories, and are increasingly used in recent years. Cast refractories, a type of irregular-shaped refractories, have excellent workability, and their basic unit and unit cost have been significantly reduced by improving the technology to improve their durability and by conducting repairs. It is the mainstream of refractories.

[0003] As for cast refractories, those using various bonding methods have been put into practical use due to the recent development of materials and construction techniques, and a fine structure is formed by combining various ultrafine powders, dispersants, flocculants and the like. The obtained construction body can be obtained. However, these dense cast refractories construction bodies,
It is heated to remove water mixed during construction by drying, and when the temperature rises, water vapor is trapped inside the construction body, and the pressure causes cracks or breaks in the construction body (hereinafter, explosion or explosion phenomenon) Problem). For this reason, the drying of the dense refractory that has been cast is performed slowly over a long period of time, which requires a longer construction period.

In order to prevent this explosion and shorten the construction period, aluminum powder (hereinafter referred to as A)
explosion prevention technology has been proposed in which H ₂ gas is generated by the reaction of Ca ²⁺ contained in alumina cement with an alkaline aqueous solution to generate H ₂ gas, and a vent for releasing water vapor is formed in advance. (Japanese Patent Publication No. 61-3)
8154).

However, since the activity of Al powder is so high that the progress of the reaction is too fast, a method has been proposed in which the surface of the particles of the Al powder is coated with an organic substance or the like to suppress the reaction (Japanese Unexamined Patent Publication No. Sho 5).
8-120573). In addition, when Al powder is used for the purpose of preventing explosion, generated H ₂ is flammable, and is liable to explode in construction in a closed space, so that careful handling is required. Further, JP-A-58-2174
In No. 72, Al-Si is used to improve the strength of the amorphous refractory.
The addition of alloy powder has been proposed.

[0006] However, the Al-Si alloy powder there is
Used to reinforce the joints of the refractory that has been applied and to improve resistance to mechanical and chemical wear at high temperatures. No disclosure is made about the solution to the problem that arises.

Recently, as a safer explosion-proofing technique than Al powder, a method has been proposed in which organic or inorganic fibers are added to a composition to form air holes (Japanese Patent Laid-Open No. 59-190).
276). Also, Japanese Patent Application Laid-Open No. 62-100483 discloses A
There has been proposed a method for preventing explosion in which basic aluminum lactate is added in addition to powder to generate fine cracks in the refractory structure to form air holes.

[0008]

The addition of Al powder [0005] In addition there can construction material at a pressure of generated H ₂ gas is a porous expanded, the internal tissue of the refractory at a pressure of H ₂ gas The cast refractory composition to which cracks are generated and to which Al powder has been added lacks preservability because the activity of Al powder is high. In addition, the cast refractory to which Al powder is added is affected by the fact that the exothermic reaction depending on the application temperature and the type of alumina cement to be blended is not constant, and it is possible to obtain a refractory construction having a stable quality. It was difficult.

[0009] Methods proposed Al powder particle surface as a solution to these problems is coated with organic material, albeit the effect of improving the storage stability, it is difficult to adjust the timing of generating the H ₂ gas, H ₂ There is a problem that it is difficult to uniformly disperse gas bubbles in the castable construction body, and coarse gas bubbles are partially formed, thereby lowering the durability of the refractory.

In addition, the method of adding organic fibers, which has been proposed as a safe method without the risk of ignition explosion due to the generated H ₂ gas, is inferior in the dispersibility of the organic fibers in the clay, and is required at the time of construction. However, there is a drawback that the amount of the refractory is limited due to an increase in water content and impaired durability of the refractory, and it is difficult to obtain a good refractory construction.

In addition, the method of adding basic aluminum lactate has a problem that layered cracks are liable to be generated in a construction body due to a large shrinkage upon drying, and the durability of a refractory is impaired. The present invention provides a castable refractory of a quality that can provide a dense refractory construction, does not explode even when subjected to rapid drying, and has no danger of igniting generated H ₂ gas. Aim.

[0012]

First, the refractory composition of the present invention is kneaded with water, applied to a desired portion by pouring, and then dried rapidly to form a furnace wall. A refractory composition of fixed form, comprising a refractory aggregate,
A composition comprising refractory powder, a predetermined amount of aluminum-silicon alloy (hereinafter, Al-Si alloy) powder, organic fibers, and a dispersant.

The method for forming a furnace wall according to the present invention is characterized in that a refractory composition containing a refractory aggregate, a refractory powder, a predetermined amount of Al-Si alloy powder, an organic fiber and a dispersant is added to a predetermined amount of water. The refractory kneaded clay obtained by mixing the refractory clay is poured into a desired furnace wall forming portion, and then the refractory surface is heated at a heating rate of 50 ° C. or more per hour. The method is characterized in that the refractory is heated and dried by performing at least until the surface temperature of the refractory reaches 500 ° C. or higher.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail and preferred embodiments. The fire-resistant aggregate of the present invention,
The composition for a cast refractory containing a refractory powder, an Al-Si alloy powder, an organic fiber, and a dispersant is kneaded by adding moisture at the time of construction, and then constructed by a cast construction method. The refractory aggregate is a main component of the refractory, and the refractory powder is a component for filling the gap between the refractory aggregates and forming a joint for connecting the refractory aggregates. The dispersant is added to increase the fluidity of the kneaded clay obtained by adding water to the composition.

The conventional cast refractory composition contains Al powder for the purpose of preventing explosion. This Al powder is easy to react with the alkaline aqueous solution, and it is difficult to adjust the amount and timing of H ₂ gas generation. However, in the case of using Al—Si alloy powder, the amount of H ₂ gas generated and the timing of generation are adjusted. it can. This is because the Si component contained in the Al—Si alloy suppresses the reactivity of the Al component and suppresses the generation of H ₂ gas. As a result, the generation of H ₂ gas is less affected by the type of alumina cement and the application temperature as compared with the case where Al powder is added, the reaction for generating H ₂ gas occurs slowly, and the flow suitable for the release of water vapor is generated. Pores can be reliably formed.

Due to the presence of the formed air holes, the cast refractory construction does not explode even if the temperature rises considerably rapidly during drying. Furthermore, the risk of ignition explosion due to the generation of H ₂ gas can also be easily prevented by the occurrence of rapid H ₂ gas as refractories obtained by adding Al powder does not occur. Further, Al-Si alloy powder is less likely to react with moisture in the air than Al powder, and for example, a bag-filled composition for a cast refractory material has good storage stability.

The amount of the Al-Si alloy powder added to the composition is 10 times the total amount of the refractory aggregate and the refractory powder in the composition.
0.02 parts by weight or more, preferably 1 part by weight or less based on 0 parts by weight. If the amount is less than 0.02 parts by weight, the generation of H ₂ gas is small, and even if organic fibers are used in combination, it is difficult to obtain the explosion prevention effect. If the amount is more than 1 part by weight, in the case of the present invention, H
₍₂₎ The amount of generated gas is large, and when used in combination with organic fibers, the refractory after construction tends to swell or crack, and the strength of the refractory decreases when many bubbles are generated and the refractory becomes porous. A more preferred amount of the Al-Si alloy powder is 0.0
4 to 0.5 parts by weight.

The Al-Si alloy powder contained in the cast refractory composition of the present invention preferably contains 60 to 95 Al.
% Of Si and 5 to 40% by weight of Si. Al-
If the Si component in the Si alloy is more than 40% by weight, the generation of H ₂ gas is slow and the generation amount is small, so that the explosion prevention effect is small. If the Si content is less than 5% by weight, the generation of H ₂ gas becomes active, and depending on the components to be added to the composition, the refractory construction tends to swell or crack. A more preferred Al-Si alloy powder is
It contains 0 to 93% by weight and 7 to 30% by weight of Si.

The Al-Si alloy powder contained in the cast refractory composition of the present invention is preferably made of an Al component and Si
The total amount of the components is 90% by weight or more, and the particle size is 0.074 m
m or less and 40% by weight or more.

When the total amount of Al and Si is 90% by weight or more, a favorable effect that variation in the reaction start time can be reduced can be obtained. Al in Al-Si alloy
The total amount of Si and Si is more preferably 95% by weight or more. Also,
When the Al-Si alloy powder contains 40% by weight or more of particles having a particle size of 0.074 mm or less, a reliable explosion prevention effect can be obtained. If the amount of particles having a particle size of 0.074 mm or less is less than 40% by weight, the generation of H ₂ is small, and the explosion prevention effect is reduced. A more preferred Al-Si alloy powder has a particle size of 0.1.
It contains 50% by weight or more of particles of 074 mm or less.

The alloy powder used in the present invention is Al-
Although it is a Si alloy powder, it is not limited to this, and other alloy powders and metal powders can be used together in a small amount within a range that does not interfere.

The Al-Si alloy powder is preferably an alloy powder in which an Al component and a Si component are uniformly dispersed. Such an alloy powder can be produced by an atomizing method or a method of pulverizing a molten solidified alloy.

The purpose of adding the organic fibers is to use the refractory aggregate previously proposed by the present inventors as a composition which can be rapidly dried,
When refractory powder, Al-Si alloy powder and a refractory composition containing a dispersing agent, by casting an amorphous refractory clay obtained by mixing a predetermined amount of water, particularly in summer It was found that if the amount of water is increased to improve the workability, the separation of the clay (the refractory aggregate will settle and the refractory applied will become non-uniform) will easily occur depending on the conditions. Is added as Further, although the effect of adding the organic fiber is effective in preventing explosion, it is not perfect.

As the organic fiber, 0.02 to 0.5% by weight based on 100 parts by weight of the total amount of the refractory aggregate and the refractory powder is used.
Is preferred. If it is less than 0.02% by weight, the effect of preventing separation is small, and if it is more than 0.5% by weight, a larger amount of water is required for improving workability, and it is not preferable because it becomes porous. More preferred organic fiber amount is 0.0
It is 3 to 0.2 parts by weight.

The organic fibers are preferably polyester fibers, vinylon fibers, polypropylene fibers, etc., and the length of the fibers is 1 to 50 mm or less, preferably 5 to 30 mm. If it exceeds 50 mm, the fluidity is reduced. The thickness of the fiber can be about several μm to 400 μm, and more preferably 3 to 100 μm. 4
If it exceeds 00 μm, workability and corrosion resistance will be reduced.

As the refractory aggregate, one selected from alumina, bauxite, diaspore, mullite, alumite shale, chamotte, quartzite, pyrophyllite, sillimanite, andalusite, spinel, magnesia, silicon carbide and graphite The above can be preferably used. As the refractory powder, at least one selected from alumina cement, refractory clay, pulverized refractory aggregate powder, fumed silica and ultrafine alumina can be preferably used.

As the refractory powder, it is preferable to use a powder having an average particle size of less than 30 μm so that a good bonding portion can be formed. Further, as a part of the refractory powder, it is preferable to use an ultrafine powder having an average particle diameter of alumina or fumed silica of 3 μm or less, preferably 1 μm or less. When an ultrafine powder of alumina or fumed silica is used, the amount of water mixed with the composition can be reduced and good fluidity can be imparted to the kneaded clay.

When alumina cement is used as a part of the refractory powder, the alumina cement contributes to the bonding of the refractory for casting, and the construction can provide practical strength in a wide range from normal temperature to high temperature. .

The preferred compounding amount of the alumina cement is 1 to 1 with respect to 100 parts by weight of the total amount of the refractory aggregate and the refractory powder.
0 parts by weight. Alumina cement is CaO / Al ₂ O
Molar ratio of ₃ can be secured a sufficiently long usable time clay was kneaded by the use of those 1.3. In addition, when refractory clay is used as a part of the refractory powder, a castable refractory having good workability can be obtained. In the present invention, the blending ratio of the refractory aggregate and the refractory powder is preferably 75 to 95% by weight for the former and 5 to 25% by weight for the latter.

In order to impart excellent fluidity to the kneaded clay, it is preferable that a dispersant selected according to the type of the refractory aggregate and refractory powder to be used is blended in the composition.
If a powdery dispersant is used, it is easy to add the dispersant to the composition to be packaged in advance. As dispersants, polyphosphates, polycarboxylates,
One or more selected from polyacrylates and β-naphthalene sulfonates can be preferably used. The dispersant is 100 parts by weight of the total amount of the refractory aggregate and the refractory powder in the composition.
It is preferable to add 0.02 to 1 part by weight based on part by weight.

The setting time of the cast refractory containing alumina cement is not constant depending on the application temperature and the type of alumina cement, and the setting is slow at a low temperature of 15 ° C. or less.
Some cure at about 30 ° C slows down, while others over 30 ° C cure rapidly. It is preferable to use a curing accelerator or a curing retarder in addition to use in order to make the curing time independent of the surrounding temperature conditions.

As the hardening accelerator, quick lime, lithium carbonate and calcium chloride can be preferably used. As the curing retarder, nitrates, phosphates, lignin sulfonates, and gluconates can be preferably used. The amount of these additives is preferably in the range of 0.01 to 1 part by weight with respect to 100 parts by weight of the total amount of the refractory aggregate and the refractory powder, and is preferably adjusted according to the construction temperature and the type of alumina cement. .

The amount of water mixed with the composition varies depending on the specific gravity and porosity of the refractory aggregate and refractory powder contained in the composition. There is a lower limit to the amount of water that can impart fluidity to the kneaded clay, and usually, 4 parts by weight or more of water is required for 100 parts by weight of the total amount of the refractory aggregate and the refractory powder. Further, in order to reduce the porosity of the refractory after the construction and secure the physical properties as a good refractory, the amount of water mixed with the composition is 100% of the total amount of the refractory aggregate and the refractory powder. It is preferably 12 parts by weight or less, more preferably 10 parts by weight or less based on parts by weight. If the amount of water mixed with the composition is large, the refractory aggregate tends to settle, and the applied refractory tends to be heterogeneous.

In the present invention, such a composition for a cast refractory is kneaded with water, applied to a desired place by pouring, and then used to form a furnace wall which does not cause explosion even if it is rapidly heated and dried. It can be formed and can be used for such purposes.

That is, the composition for a cast refractory according to the present invention is mixed with water for imparting fluidity to the composition based on the above-mentioned mixing ratio, and poured into a furnace wall forming portion (refractory powder is not used). In the case of a composition that does not have sufficient self-fluidity, such as those made of alumina cement alone or those added with clay, apply the composition while applying vibration.) , Preferably 4 per hour
No explosion occurs even when dried up to 1400 ° C at a heating rate of 00 ° C or less.

If the temperature rise rate is less than 50 ° C./hour, there is little advantage compared to the conventional drying method, and the drying time is not particularly shortened. If the rate is more than 400 ° C./hour, a considerably large drying means is required. Even if the temperature is raised quickly, the heat generated in the furnace wall becomes insufficient, and complete dehydration takes time, which is not practical in many cases. Further, when the temperature exceeds 400 ° C./hour, there is a problem that spalling cracks are formed on the surface of the amorphous refractory.

The heating rate can be selected and determined according to the composition ratio of the composition, the shape and thickness of the furnace wall to be formed, the operating conditions to which the furnace wall is exposed, and the like. Is possible even at 300 ° C. or more per hour.

The maximum heating temperature is determined depending on the furnace. If the furnace is heated up to about 500.degree. C., a usable furnace wall can be formed. Usually, a desired furnace wall is formed by heating to 1000.degree. C. or more. Since rapid heating and drying and drying in a short time are possible in this manner, the furnace can be quickly restarted.

In the present invention, the surface temperature at the time of heating and drying is defined as 1 to 2 from the surface of the refractory constructed as a furnace wall.
It is the temperature measured at the tip of a thermometer (usually a thermocouple) embedded at the mm position.

In the present invention, the heating rate is also affected by the thickness of the irregular-shaped refractory. For example, the thicker the construction thickness, the longer it takes to dry inside. However, since the applied thickness of the composition for refractory of the present invention is usually in the range of about 100 to 1000 mm, if it is heated and dried at a predetermined heating rate until the surface temperature becomes 500 ° C. or more, the heating and drying is performed. The furnace wall can be formed without explosion or cracking. At this time, there is no problem even if there is an undried portion in the interior, because the interior is gradually dried by the heat received when the furnace is actually used.

In general, the refractory composition of the present invention is applied to a furnace from the back of the furnace on an inner surface on which a permanent refractory and an adiabatic refractory are sequentially applied.

The Al—Si alloy powder finally becomes A
Since it changes into l ₂ O ₃ and SiO ₂ and becomes a refractory component, it has excellent characteristics as a refractory, and the volume increases when the Al—Si alloy powder is changed to Al ₂ O ₃ and SiO ₂ . A cast refractory with excellent volume stability is obtained. Further, in the construction using the cast refractory composition of the present invention, Al ₂ O generated by oxidizing Al—Si alloy powder is generated.
_{3. Since} SiO ₂ contributes to the bonding strength, a refractory excellent in strength can be obtained.

Further, by adding the organic fibers to these refractory compositions, they have excellent dispersibility at the time of kneading and hardly separate the clay even when the amount of water is increased. An effect is also observed on formation.
The organic fibers are completely burned out by heating and drying, do not reduce the corrosion resistance, and do not generate toxic gas during combustion.

[0044]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

As a refractory aggregate, an Al ₂ O ₃ content of 89 was used.
Coarse particles having a particle size of 1.68 to 5 mm, medium particles having a particle size of 0.1 to 1.68 mm, and a weight ratio of 7% by weight, a SiO ₂ content of 7% by weight and an Fe ₂ O ₃ content of 1.3% by weight; Particle size 0.02-
Bauxite aggregate consisting of fine grains having a diameter of 0.1 mm and an average particle diameter of 0.03 mm was used.

The content of Al ₂ O ₃ and CaO in the refractory powder constituting the bonding portion of the refractory was 55% by weight, respectively.
Alumina cement having an average particle size of 9 μm, Al ₂ O _{3 having} a purity of 99.6% by weight, Bayer alumina having an average particle size of 4.3 μm, and SiO _{2 having} a purity of 9%.
Fumed silica having an average particle diameter of 0.8 μm at 3% by weight was used. As the dispersant, powder of sodium tetraphosphate (Na ₆ P ₄ O ₁₃ ) containing 60.4% by weight and 39.6% by weight of P ₂ O ₅ and Na ₂ O, respectively was used.

As the Al—Si alloy powder, Al component 8
Alloy powder (a) containing 0% by weight and 20% by weight of Si component and Al
Alloy powder containing 90% by weight of Si component and 10% by weight of Si component (b)
Was used. The average particle diameters of the Al—Si alloy powders (a) and (b) are 28 μm and 30 μm, respectively.
It contains 92% and 89% of particles of 74 mm or less, respectively. The Al powder used in the comparative example had a purity of 99% and an average particle size of 30 μm. As the organic fiber, a polyester fiber having a thickness of 1 denier and a length of 10 mm was used.

A refractory aggregate, a refractory powder, an organic fiber, a dispersant, an Al—Si alloy powder and an Al powder were weighed, and a composition for a cast refractory having a formulation (unit: parts by weight) shown in the table was prepared. Obtained. Next, water (parts by weight) in the amount shown in the table was added to 100 parts by weight of the total amount of the refractory aggregate and the refractory powder in the composition, kneaded in a universal mixer for 3 minutes, and poured. I got the soil. This kneaded material has an inner size of 40 mm x 40 mm
× 160mm formwork and inner diameter 100mm × height 100m
m into a mold, and a cast refractory specimen (Examples 1 to 3)
13, of which Examples 1 to 7 were Examples and Examples 8 to 13 were Comparative Examples.

Regarding the fluidity of the cast refractory clay, for each of Examples 1 to 13 having self-fluidity, each of the kneaded clays immediately after kneading was prepared by using an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm and a height of 150 m.
m, and poured into a truncated cone-shaped cone with open upper and lower ends to fill the cone, and withdraw the cone upward.
The spread diameter of the clay when allowed to stand for 2 seconds was measured with calipers in two directions, and the average value was defined as the clay flow value.

Regarding the separation, the amount of water was increased to 40 mm
The cross section of a specimen of × 40 mm × 160 mm cast by casting was observed, and the presence or absence of separation was determined based on the degree of separation of the aggregate.

The porosity and the bulk specific gravity were measured at 110 ° C. for 2 hours.
After drying for 4 hours, it was measured according to the method specified in JIS-R2205. Flexural strength is 40mm x 40m
An mx160 mm specimen was cured at room temperature (in the table, indicated as flexural strength A), and a dried specimen was 14 specimens.
It was measured for one baked at 00 ° C. for one hour (shown as bending strength B in the table).

The dimensional change was measured by measuring the dimensional change of a test piece fired at 1400 ° C. for 1 hour, and expressed as a ratio based on the dimension before firing. In the table, "swelling" means that remarkable swelling of about several percent was observed.

The presence or absence of a crack is a result of examining the appearance of a test specimen that has been demolded after curing. The explosion resistance was determined by measuring a 100 mm diameter x 100 mm height specimen taken out of the mold.
It was put into an electric furnace maintained at 200 ° C., and the presence or absence of explosion was examined and evaluated. Tables 1 and 2 show these results.

Table 3 shows the test results of cast refractories in which a large amount of alumina cement was added to the refractory powder and no other refractory powder was added, as Examples 14 to 21. Since the clay of the refractory for casting is not sufficiently self-flowing, its flow value is determined by using a flow cone defined in JIS-R5201, and pouring the clay immediately after kneading into a flow cone placed on a shaking table. After the filling, a vibration of 3 G was given, and the spread diameter of the clay after 10 seconds was measured with calipers in two directions, and the average value was taken as the flow value. The other evaluation methods were the same as in Example 1.

Table 4 shows the test results of the cast refractories containing clay as Examples 22 to 28. The used refractory aggregate, refractory powder and other raw materials are Examples 1 to
13 and the evaluation method is the same as in Examples 14 to 21. In Examples 14 to 21, the Al-Si alloy powder (a) was not blended, and in Examples 22 to 28, the Al-Si alloy powder (b) was not blended. Example 14 in Tables 3 and 4
Examples 17 to 22 and Examples 22 to 24 are Examples, and Examples 18 to 21 and 25 to 28 are Comparative Examples.

The expression "swelling" in the column of dimensional change in the table means that remarkable expansion of about several percent was observed. In addition, those having a negative dimensional change rate in Examples 21 and 28 indicate that a negative dimensional change rate (shrinkage) was shown.

As can be seen from the table, the Al-Si of the present invention
When the composition for a cast refractory containing an alloy powder and an organic fiber is used, a vent for releasing water vapor is secured even if the applied refractory is dense, and the cast refractory containing an Al powder is used. As described above, no swelling or cracking occurs due to the generation of H ₂ gas, and no explosion occurs even when the temperature is rapidly raised and dried. The physical properties of the constructed cast refractories are also good because they are dense.

On the other hand, a cast refractory containing Al powder causes swelling and cracking when the content of Al powder is large,
The preferable content of the Al powder varies depending on the kneading temperature of the kneaded material. In addition, even when the amount of water is increased to improve workability, by adding moderately organic fibers,
There is no separation, and the physical properties of the cast refractory that has been installed are excellent because it is dense.

[Example 29] The cast refractory of Example 3 in Table 1 was mini-tundish 1000 mm x 1000 mm.
Was installed in the part. The thickness of this refractory is 250mm,
In addition, a heat-insulating castable is provided on the back surface up to a thickness of 100 mm. After curing, one-side heating was performed using an oil burner, and the surface temperature of the furnace wall was increased to 1000 ° C. at a rate of 200 ° C./hour and dried. The temperature distribution in the mini-tundish furnace was about ± 20 ° C. There was no explosion during drying, and no cracks were found on the furnace wall surface after the drying was completed. A cross section was observed by cutting in the thickness direction, but no crack was found.

Example 30 The amorphous refractory composition of Example 7 in Table 1 was applied to a mini-tundish in the same manner as in Example 29, and a drying test was performed. In this case, the surface temperature of the furnace wall was raised at a rate of 300 ° C./hour and dried to 1400 ° C. No explosion occurred during drying, and no cracks were observed on the furnace wall surface or the internal cut surface after drying was completed.

Example 31 The amorphous refractory composition of Example 22 in Table 4 was applied to a mini-tundish in the same manner as in Example 29 while applying vibration thereto, and a drying test was performed. In this case, the surface temperature of the furnace wall was raised to 1000 ° C. at a rate of 100 ° C./hour and dried. Similarly, there was no explosion during drying, and no cracks were observed after drying.

Example 32 The amorphous refractory composition of Example 13 in Table 2 was applied to a mini-tundish in the same manner as in Example 29, and a drying test was performed. In this case, the surface temperature of the furnace wall is set to 200 ° C./hour.
At a heating rate of 1200 ° C., but explosion occurred during drying, and a part of the furnace wall surface was blown off and peeled off. After the drying was completed, many cracks were observed in the furnace wall.

[Example 33] The amorphous refractory composition of Example 16 in Table 3 was applied while applying vibration to a mini-tundish in the same manner as in Example 29, and the furnace wall surface temperature was increased to 1000 ° C at a rate of 500 ° C / hour. And heated to dryness. No explosion was observed during the heating and drying, but after the drying was completed, countless spalling cracks were observed on the furnace wall surface.

From the above results, a correlation was observed between the drying test in the mini-tundish and the cracking and explosion tests in the composition, and the evaluation in the composition was based on the furnace wall under rapid heating conditions. It was also found that the method can be applied to the evaluation of the formation method of slabs.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

[Table 4]

[0069]

The cast refractory composition of the present invention, which contains a predetermined amount of Al-Si alloy powder and organic fibers, is made of Al-Si
Since the activity of the alloy powder is lower than that of the Al powder, the composition has good preservability, and the clay obtained by mixing the composition with water does not cause a separation phenomenon even if the water content is large. Al-
Since the Si alloy powder reacts more slowly with the alkaline aqueous solution than the Al powder, and a passage through which water vapor escapes is secured in the construction body, the explosion does not occur even if the temperature is rapidly raised and dried. further,
A dense refractory furnace wall having good high-temperature characteristics can be obtained.

Further, the method for forming a furnace wall of the present invention does not require a long drying time in the related art, can employ drying by direct fire, and can significantly shorten the construction period. Further, the unit cost of the raw material can be reduced, the construction work, environmental safety and the like can be improved, and its industrial value is enormous.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuya Noda 5-6-1 Umei, Takasago City, Hyogo Prefecture Asahi Glass Co., Ltd.

Claims (13)

[Claims] 1. Refractory aggregate, refractory powder, aluminum
A pourable composition comprising a silicon alloy powder, an organic fiber and a dispersant, wherein the aluminum-silicon alloy powder and the organic fiber comprise a total amount of the refractory aggregate and the refractory powder of 10%.
0.02 to 1 part by weight and 0. 1 part by weight, respectively.
A composition for a cast refractory, wherein the composition is from 02 to 0.5 part by weight. 2. The aluminum-silicon alloy powder,
For a total amount of 100 parts by weight of refractory aggregate and refractory powder,
The composition for a cast refractory according to claim 1, which is contained in an amount of 0.04 to 0.5 part by weight. 3. The aluminum-silicon alloy powder according to claim 1,
The composition for a cast refractory according to claim 1 or 2, comprising 60 to 95% by weight of Al and 5 to 40% by weight of Si. 4. The aluminum-silicon alloy powder,
4. The composition for a cast refractory according to claim 1, wherein the total content of Al and Si is 90% by weight or more and 40% by weight or more of particles having a particle size of 0.074 mm or less. 5. The cast refractory according to claim 1, wherein the organic fiber contains 0.03 to 0.2 parts by weight based on 100 parts by weight of the total amount of the refractory aggregate and the refractory powder. Object composition. 6. The organic fiber according to claim 1, wherein the organic fiber is a polyester fiber and / or a vinylon fiber having a length of 1 to 50 mm.
2, 3, 4 or 5 cast refractory compositions. 7. The cast refractory composition according to claim 1, wherein said refractory powder contains alumina cement or refractory clay. 8. Refractory aggregate, refractory powder, aluminum
The aluminum-silicon alloy powder and the organic fiber contain silicon alloy powder, organic fiber, and dispersant, respectively.
~ 1 and 0.02 to 0.5 parts by weight of the refractory composition contained in the refractory composition, a predetermined amount of water is mixed, and the obtained refractory clay is poured into a desired furnace wall forming portion. The refractory is heated and dried by heating the refractory surface at a heating rate of 50 ° C. or more per hour and performing the heat treatment at least until the surface temperature of the refractory reaches 500 ° C. or more. A method for forming a furnace wall. 9. The method for forming a furnace wall according to claim 8, wherein said heating rate is 100 ° C./hour or more. 10. The method for forming a furnace wall according to claim 8, wherein the heating rate is 400 ° C./hour or less. 11. The heat treatment according to claim 1, wherein the surface temperature of the refractory is 10 or less.
11. The method for forming a furnace wall according to claim 8, 9 or 10, which is performed until the temperature reaches 00 ° C or more. 12. The aluminum-silicon alloy powder contains 60 to 95% by weight of Al and 5 to 40% by weight of Si, the total of which is 90% by weight or more and the particle size is 0.074 mm or less. The method for forming a furnace wall according to any one of claims 8, 9, 10, and 11, wherein the furnace wall contains at least 40% by weight of particles. 13. A method according to claim 8, wherein said refractory powder contains alumina cement or clay.