JP2001302372A - Metal oxide carbon-base clinker and refractories - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide metal oxide carbon-base clinker as a refractory raw material which allows the increase of carbon content, an improvement in permeability resistance and the uniform distribution of carbon and has excellent corrosion resistance, spalling resistance and oxidation resistance. SOLUTION: This clinker is formed by impregnating the porous sintered compact of metal oxide with carbon source raw material in such a manner that this it is introduced into pores to impart its porous structure or subjecting the impregnated matter to baking or caulking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal oxide-carbon clinker and a refractory containing the same as a refractory material, and more particularly to a refractory for hot metal and molten steel, a refining vessel, and a refractory for continuous casting in the steelmaking industry. Objects, castables, spraying materials,
Clinker as a refractory material or refractory material that can be suitably used for various irregular-shaped refractories such as gutter materials, repair materials, refractories for non-ferrous metal refining furnaces, refractories for cement, refractories for glass kilns, and the like. Things.

[0002]

BACKGROUND ART Conventionally, in the fields of iron making and non-ferrous steel,
Metal oxides such as alumina, magnesia, magnesia-alumina spinel, zirconia, silica and the like have been widely used as refractory materials or refractory materials, and in recent years, excellent corrosion resistance and penetration resistance of carbon. sex,
Utilizing spalling resistance, carbon-containing refractories such as alumina-carbon bricks and magnesia-carbon bricks are widely used as containers for refining molten steel, containers for transportation, nozzle bricks for continuous casting, and the like. Further, an alumina-carbon castable using an alumina-carbon aggregate obtained by granulating a mixture of alumina and carbon, and a magnesia-carbon amorphous refractory using spheroidizing graphite graphite are used. Proposals have also been made (JP-A-11-236272, JP-A-11-2462).
No. 72).

In the production of the above-described refractory containing carbon, if the amount of carbon added to the material giving the refractory is increased in order to further enhance the effect due to the presence of carbon, the refractory is generally formed from the compound. There is a problem such as the occurrence of a reversion phenomenon in the refractory, which significantly lowers the production yield, and the fact that carbon is oxidized during the use of the refractory, which causes a reduction in the life of the refractory itself. However, there remains a problem that the carbon content in the refractory cannot be simply increased. For this reason, for example, in an alumina-carbon sliding nozzle that is a refractory for continuous casting, after forming such a nozzle from a refractory material, a plurality of pitch impregnation operations are performed on the gap, By increasing the amount of carbon in the nozzle as a whole, those with enhanced properties are used.In addition, in magnesia-carbon bricks used in converters and ladles, each carbon amount is about About 20% by weight or 10% by weight,
It has been recognized that despite the addition of metals such as aluminum and silicon as antioxidants, the life may be significantly reduced by the oxidation of carbon.

Further, porous refractories used in ladles and tundishes used for the purpose of equalizing molten steel components and the temperature are mainly made of alumina. Since the gas blowing function may be hindered by permeation of slag, a porous refractory having excellent resistance to penetration of molten steel and slag is required.

On the other hand, in the case of amorphous refractories mainly composed of alumina, such as castables, the use conditions are severe and the
Further improvement in corrosion resistance and spalling resistance is required, and as one of the countermeasures, an amorphous refractory containing carbon as described above has been proposed. Separation phenomena based on the specific gravity difference easily occur,
There is a problem of lack of uniformity as a refractory, and therefore, as described above, a method according to JP-A-11-246272 using spheroidal graphite and spheroidizing a mixture of alumina and carbon, Japanese Patent Application Laid-Open No. H11-236272, which uses the granulated material as an aggregate, has been proposed. However, none of these methods has sufficiently solved the problem. That is, the spheroidal graphite alone does not solve the separation phenomenon based on the difference in specific gravity, and in granulation of a mixture of alumina and carbon, whether those raw materials are macroscopically mixed using a resin binder, Alternatively, since the mixture is formed, dried, and then pulverized, it is presumed that the strength of the granules is low and the porosity is also at the level of conventional refractories, and therefore, the corrosion resistance is still high. It seems that there are still issues related to this.

[0006]

Here, the present invention has been made in view of such circumstances, and the problems to be solved are to increase carbon content, improve permeation resistance,
Another object of the present invention is to provide a metal oxide-carbon clinker as a refractory material which enables uniform distribution of carbon and which is excellent in corrosion resistance, spalling resistance and oxidation resistance. An object of the present invention is to obtain a refractory having excellent properties such as corrosion resistance, spalling resistance and oxidation resistance by using such a clinker as a refractory material.

[0007]

In order to solve the above-mentioned problems, the present inventors have made various attempts to introduce carbon into refractories using metal oxides such as alumina and magnesia, which are currently widely used, as refractory materials. As a result of the study, unlike the method of directly introducing carbon to such a refractory or forming a refractory from a mixture obtained by mixing a refractory material and carbon, such a method is used. By introducing carbon into the porous structure of the metal oxide sintered body particles constituting the refractory material that provides a refractory material, and by allowing carbon to enter the pores of such a sintered body, The present inventors have found that excellent characteristics such as uniform carbonization, further increase of carbon, and improvement of oxidation resistance can be exhibited in the above, and the present invention has been completed.

That is, in order to solve the above-mentioned problems, the present invention, which has been completed on the basis of such findings, provides a porous sintered body of a metal oxide with pores that give the porous structure thereof. A metal oxide-carbon clinker characterized by being impregnated with a carbon source material or baking or caulking the impregnated material as described above.

Therefore, in the metal oxide-carbon clinker according to the present invention, since the sintered body of the metal oxide is used as a base, the metal oxide-carbon clinker has high strength and is porous. Even so, the diameter of the pores that provide it is also small, and in general, the carbon source material or carbon generated therefrom is placed in the micron-order pores of such a porous sintered body of a metal oxide. Into the sintered body to form a structure uniformly dispersed throughout the sintered body. Therefore, even if the carbon content in the sintered body is increased or even in an oxygen atmosphere, it is oxidized. Difficultly, and due to the presence of such carbon, it becomes a refractory material or a refractory material having excellent properties such as penetration resistance to molten steel and slag, corrosion resistance, and spalling resistance.

[0010] According to one preferred embodiment of the metal oxide-carbon clinker according to the present invention, the carbon source material is a pitch, and the pitch is heated and liquefied to form a sintered body. Impregnated. Such a pitch is effective as a carbon source material, and is easily fluidized and liquefied by heating, so that the impregnation operation on the sintered body can be effectively performed.

According to another preferred aspect of the present invention, the carbon source material is a carbon fine powder such as carbon black, coke, mesophase carbon, and the like.
The sintered body is impregnated with the carbon fine powder in a slurry state.

Further, according to another preferred embodiment of the metal oxide-carbon clinker according to the present invention, the carbon source material is an organic resin such as a phenol resin, a furan resin, a polyacrylonitrile, a melamine resin, and an epoxy resin. The organic polymer material is a polymer material, and the organic polymer material is impregnated in a liquid form into the sintered body, and is introduced into pores giving a porous structure.

In the present invention, preferably, aluminum, an aluminum-magnesium alloy, magnesium,
An embodiment in which a metal antioxidant such as silicon is mixed and the sintered body is impregnated with the obtained mixture in the form of a mixture or in a slurry state is advantageously employed. By the coexistence of such a metal antioxidant, the oxidation resistance of the clinker can be further improved.

The present invention also provides a refractory characterized in that it contains the metal oxide-carbon clinker as described above as a refractory material. Refractory, based on the performance of the clinker described above, penetration resistance to molten steel and slag,
It has excellent corrosion resistance, spalling resistance and oxidation resistance.

[0015]

The metal oxide constituting the porous sintered body serving as the base of the metal oxide-carbon clinker according to the present invention as described above has been widely used as a material for providing a refractory material. Have been, alumina,
Magnesia-alumina-based spinel, magnesia, zirconia, zircon sand, etc., a normal component such as a raw material that gives such a metal oxide, is fired in the same manner as in the prior art to obtain a predetermined porous sintered body. Is formed,
Will be used.

For example, a fine powder of the above-mentioned metal oxide raw material was prepared, and it was first granulated by a granulator to obtain a desired granulated product, and then the granulated product was dried. Thereafter, by firing at a high temperature at a temperature corresponding to each metal oxide, a porous sintered body of the target metal oxide is obtained. The particle size of the raw material used to form such a granulated product is not particularly limited, but generally, a granulated product having a size of about 10 to 30 mm is easily obtained. It is desirable that the particle size be as small as possible. Generally, it is used in a size of 100 μm or less, and the average particle size is about 30 μm or less, particularly 20 μm or less.
It is desirable that it is not more than μm. When granulating the metal oxide raw material, as a granulating binder, a binder generally used in the field of refractories, such as polyvinyl alcohol, methyl cellulose, molasses, sodium ligninsulfonate, may be used as it is, Further, as the granulator, a spray dryer, a rolling granulator, or a rotary mixer such as a Henschel mixer or an Erich mixer is used. The granulated material thus obtained is fired at a high temperature using a heating kiln such as a rotary kiln or a shaft kiln in order to impart necessary strength. It is a porous sintered body of the product.

As described above, a fired body or sintered body made of a metal oxide obtained by firing a metal oxide raw material has a porous structure whose porosity and pore diameter are different depending on the firing conditions. However, in the present invention, in general, a sintered body having a porosity (apparent) of about 50% or less, preferably 40% or less is advantageous in that its pore diameter can be kept small. And the lower limit of the porosity is generally 1% or more for effective introduction of the carbon source material according to the present invention.
Desirably, it will be 5% or more. Furthermore, the diameter of the pores giving such porosity is generally proportional to the porosity, the larger the porosity, the larger the pore diameter, but in the present invention, such a pore is If the fine pore diameter is too large, the carbon source material introduced there is likely to be oxidized under the influence of oxygen in the atmosphere, which may adversely affect the durability in a real furnace, Generally, those having a pore diameter of about 10 μm or less, usually about 5 μm or less will be advantageously used.
If the pore diameter is too small, it becomes difficult to introduce the carbon source material according to the present invention into the pores. Therefore, the lower limit is generally about 0.1 μm, preferably about 0.5 μm. Will be done.

In the present invention, such a porous sintered body of a metal oxide is impregnated with a predetermined carbon source material and introduced into pores giving the porous structure. Therefore, only when a predetermined carbon source material is introduced into the pores of the porous sintered body, the excellent action or effect according to the present invention can be exhibited. The carbon source material as the impregnating agent used here is substantially carbon (material) composed of only carbon.
In addition, those that provide a carbon material by removing unnecessary components by volatilization or burning, and further, those that are carbonized by baking or the like to generate a carbon material are used, such as carbon black, coke, and mesophase. In addition to carbon materials such as carbon, various pitches such as coal tar pitch, petroleum pitch, wood tar pitch,
Further, organic polymer materials such as phenol resin, furan resin, polyacrylonitrile, melamine resin, and epoxy resin are used.

When impregnating the porous sintered body with such a carbon source material, a known method is appropriately employed according to the properties or characteristics of such a carbon source material.
For example, in the state of being heated and liquefied, or in the case of a solid, in the state of a slurry of the fine powder, and in the case of being supplied in the state of liquid, in the state as it is, and dissolved in an appropriate solvent, In such a solution state, the porous sintered body is impregnated.

In order to impregnate such a carbon source material into a porous sintered body in an advantageous manner, to penetrate into the pores thereof, and to effectively increase the content (impregnation amount), the carbon source material is used. A method of performing the material impregnation operation under the action of high pressure, or performing a vacuum treatment (degassing treatment) on the porous sintered body prior to the impregnation operation, and then performing the impregnation operation, A method including a combination of the vacuum treatment and the impregnation operation under a high pressure is preferably employed. In particular, when the porosity of the porous sintered body is low or when the pore diameter is small, the vacuum treatment and / or the high pressure described above may be used to increase the impregnation amount of the carbon source material to be impregnated. It is desirable to employ the impregnation operation in the above. Furthermore, when impregnating the pitch which is a carbon source material, the size of the target porous sintered body is large, for example, when impregnating a porous sintered body having a particle size of 40 mm or 50 mm, the baking or coking described later is performed. At a temperature similar to the heat treatment temperature, the porous sintered body is preheated, and then the pitch is impregnated. It can be impregnated.

As for the impregnation amount (content) of the carbon source material in the impregnated material (porous sintered body + carbon source material) thus obtained, the refractory property increases as the impregnation amount increases. The impregnation amount is not limited at all because various properties such as corrosion resistance and spalling resistance can be improved, but generally the amount of impregnation is not more than about 50% by weight, preferably not more than 35% by weight. The impregnation amount will be the proportion. Then, in order to obtain the desired amount of impregnation of the carbon source material, the impregnation conditions are appropriately selected.For example, when impregnating the carbon material described above, it is turned into a fine powder and applied in a slurry state. In addition, the solid concentration in the slurry is adjusted, and in the case of pitch impregnation, the viscosity and the impregnation time when heating and liquefying the pitch are adjusted.

When the porous sintered body is impregnated with the carbon source material as described above, the carbon source material further includes:
An antioxidant consisting of a metal such as aluminum, aluminum-magnesium alloy, magnesium, silicon, etc., in other words, a metal antioxidant is mixed and in the form of the resulting mixture or in the form of a slurry. In this state, the sintered body is impregnated. In addition, such a metal antioxidant is generally mixed with a carbon source material in a fine powder form, and introduced together with the carbon source material into the pores of the porous sintered body. . By introducing such a metal antioxidant, oxidation of the carbon source material or the carbon material derived therefrom can be effectively suppressed or prevented, and the durability of the refractory material and further the refractory obtained therefrom ( Life) can be effectively improved.

The metal oxide-carbon clinker according to the present invention is intended for the carbon source material impregnated material of the porous sintered body obtained as described above, and is also baked or impregnated with such impregnated material. Those that have been subjected to caulking are also covered. Such baking or coking (coking) is a heat treatment for removing volatile components in a carbon source material such as pitch or for carbonizing the carbon source material to increase the carbon content. 200 to 40
A temperature of about 0 ° C. is employed, and in a coking (coking) operation, a temperature not exceeding 1000 ° C. is employed to heat-treat the impregnated material. By performing such a baking or coking operation, the carbon content of the carbon source material introduced into the pores of the porous sintered body can be increased, so that the refractory material or However, even when such a baking or coking operation is not performed, the metal oxide formed of the porous sintered body obtained by introducing the carbon source material into the pores can be obtained. The object-carbon clinker is applied to a predetermined application, and the baking or coking is performed during use by being heated in the application, so that the above-mentioned characteristic or characteristic intended is obtained. It will be exerted gradually.

In this way, the porous sintered body of the metal oxide impregnated with the carbon source material can be used as it is or after being subjected to a suitable heat treatment consisting of baking or coking. (Clinker), and also used as refractory, jaw crusher,
Using a crusher such as a roll crusher, fret mill, ball mill, etc., the required particle size is, for example, 3 to 5 mm, 1 to
It is pulverized so as to be separated into 3 mm, 1 mm or less, and fine powder, and is used as a target refractory material as the metal oxide-carbon clinker according to the present invention. Further, such a metal oxide-carbon clinker having a predetermined particle size is molded in the same manner as in the prior art, and is applied to various uses as a refractory having a predetermined shape such as a brick or a porous refractory.

As described above, since the porous sintered body of the metal oxide constituting the metal oxide-carbon clinker according to the present invention is fired at a high temperature, it has a high strength and a small pore diameter. The carbon source material is introduced into such small micron-order pores to form a structure uniformly dispersed and contained throughout the sintered body. Therefore, it is hardly oxidized even in an oxygen atmosphere, and its oxidation resistance can be further improved by adding an antioxidant such as a metal. It exhibits excellent properties such as resistance to molten steel penetration, resistance to slag penetration, corrosion resistance and spalling resistance.

For example, if a brick is formed using an alumina-carbon clinker in which pitch is impregnated into a porous sintered body of alumina as a metal oxide, the corrosion resistance and permeation resistance of such a brick can be improved. The spalling resistance and the like can be effectively improved.

Further, conventionally, a sliding nozzle or the like which has been used by impregnating pitch into a formed brick and further performing a heat treatment such as coking is used by using an alumina-carbon clinker according to the present invention. By molding such a brick, it is possible to omit the step of impregnating the brick, and its economic effect becomes great.Moreover, by using it for a porous refractory, the penetration of molten steel can be prevented. Dramatic improvement in durability can also be expected. Furthermore, it can be advantageously used as a refractory material for continuous casting such as immersion and long nozzles.

Further, magnesia is used as the metal oxide.
The magnesia-alumina spinel-carbon clinker according to the present invention, which uses an alumina spinel,
Gutter materials, bricks for mixed iron cars, can be suitably used as a refractory material, and zirconia-carbon clinker according to the present invention using zirconia as a metal oxide is a refractory for powder lines of immersion nozzles. As a material,
This will greatly contribute to improving the durability.

Incidentally, in recent years, a vacuum degassing apparatus (RH)
, Low magnesia-carbon bricks are being used, but the magnesia-carbon clinker according to the present invention can also be advantageously used for this low magnesia-carbon as a refractory material.

The metal oxide-carbon clinker according to the present invention can be advantageously used also as an alumina, magnesia-alumina, magnesia castable or various repair materials. Among those amorphous refractories, carbon (source material) impregnated according to the present invention does not show any separation phenomenon due to a difference in specific gravity or a shape difference as in the conventional production method. All manufacturing problems will be solved. Incidentally, the clinker according to the present invention, without performing any crushing operation,
It can be used as it is as a giant particle of an amorphous refractory in its original shape, or as another use example, for example, as a material for improving the casting surface of a cast iron casting.

Further, one of the major features of the metal oxide-carbon clinker according to the present invention is oxidation resistance. In particular, a known carbon-containing refractory is produced by mixing and kneading a carbon material such as scale graphite and earth graphite together with other refractory materials, and the refractory thus produced. Since the size of the gap or void is as large as about 10 to 20 μm, it is easily oxidized due to the influence of oxygen in the atmosphere, and adversely affects the durability in an actual furnace. The porous sintered body of the metal oxide before pitch impregnation, in other words, the pore diameter of the porous sintered body fired at a high temperature is several μm or less, and the pitch impregnated, and further the pore diameter after coking, Since it is smaller, it is hardly affected by oxygen as in the conventional refractory, and a great feature can be found there.

The refractory material obtained by using the metal oxide-carbon clinker according to the present invention, which is excellent in spalling resistance, slag penetration resistance, corrosion resistance, and oxidation resistance as described above, as a refractory material. That is, the durability (life) of the product is drastically improved.

[0033]

EXAMPLES In order to clarify the present invention more specifically, some examples of the present invention will be shown below.
It goes without saying that the invention is not in any way restricted by the description of such an embodiment. In addition, the present invention, in addition to the following examples, in addition to the above specific description, various modifications based on the knowledge of those skilled in the art, unless departing from the spirit of the present invention,
It should be understood that modifications, improvements and the like can be made.

Example 1 First, alumina particles having a particle diameter of 50 μm or less and an average particle diameter of about 5 μm were spherically granulated by a Henschel mixer using a polyvinyl alcohol (PVA) solution as a binder. A granulated product having a diameter of about 20 mm was obtained. Next, the obtained granulated product was heated at 120 ° C. for 4 hours.
After drying for 8 hours, it was fired in a rotary kiln at a temperature of 1800 ° C. to obtain a fired body (porous sintered body) having an apparent porosity of about 32%. Then, the obtained fired body is impregnated into a tar pitch having a temperature of 200 ° C. and a liquid viscosity of about 17 centipoise, and the tar pitch impregnation amount (residual carbon amount).
Obtained a granulated product of about 15% by weight. Thereafter, 2 kg of the fired body impregnated at such a pitch is put into a length of 200 mm,
It is housed in a container made of iron net of 150 mm in width and 70 mm in height, and it is housed in a metal sheath made of stainless steel. The periphery of the sheath is made of coke to prevent oxidation. It was sealed and coked at a temperature of 450 ° C. for 5 hours. The carbon content of the fired body after the coking was about 4.6% by weight. Further, the same fired body having a pitch impregnation amount of about 15% by weight was subjected to a coking treatment at 400 ° C., 500 ° C., or 550 ° C. for 5 hours. Further, in order to examine the carbon content after the coking, the coking time was set to 1, 2,
Coking was performed for 3, 4 or 6 hours.
In addition, the same investigation was performed also on the condition which does not use a metal sheath. Table 1 below shows the relationship between the coking temperature / time and the carbon content (%) in the fired body, obtained in an experiment using a metal sheath.

[0035]

[Table 1] (Note) Carbon content unit: wt%

As is apparent from the results shown in Table 1, in the case of coking using a metal sheath, the carbon content after pitch impregnation and coking increases as the coking temperature increases, and when the coking temperature is constant, the carbon content remains constant. It is understood that the time decreases as the time increases. On the other hand, the carbon content in the case of coking without using the metal sheath did not show a large difference from the value in Table 1 above, but a tendency to burn when the coking temperature was high was observed. In addition, when the particles after the coking were cut at the center, it was confirmed that the carbon had permeated the entire cut surface evenly and had penetrated deep into the pores.

The particles obtained by coking at a coking temperature of 450 ° C., 500 ° C., and 550 ° C. obtained by coking at 5 hours × 500 ° C. were respectively pulverized using a jaw crusher. Particles sized to 2.83 mm (Example 1 of the present invention) were obtained. Then, 100 g of the sized particles are treated at a temperature of 1000 ° C. for 30 minutes.
After heating in an electric furnace, the operation of rapidly cooling in water was repeated three times. If cracks occur in the particles by this operation, the particles are crushed and refined, but the finely divided particles are removed, and the weight ratio of the uncrushed particles is measured as a measure of the spalling resistance of the particles themselves ( (Non-breakage rate), and the results are shown in Table 2 below. Comparative Example 1 shown in Table 2 shows the results of measuring the non-breakage rate in the same manner as described above using the particles before impregnation with the pitch, that is, using the as-fired particles.

[0038]

[Table 2]

As is evident from the results in Table 2, the spalling resistance of the pitch-impregnated alumina-carbon-based particles themselves was considerably improved as compared with ordinary alumina particles (Comparative Example 1). It is recognized that there is.

Example 2 The particle size is 50 μm or less and the average particle size is about 5
μm alumina particles were made into a slurry using a PVA solution, dehydrated, and extruded to a diameter of about 1 μm.
A cylindrical granulated material having a size of 5 mm and a length of about 25 mm was obtained. Next, the obtained granules were dried and fired in the same manner as in Example 1 to obtain a fired body having an apparent porosity of about 6.1%. Further, the obtained fired body is 1.3 ×
After vacuum treatment under reduced pressure of 10 ³ Pa (10 mmHg) or more, about 9.8 × 10 ⁵ Pa (10 kg / cm
² ) While applying the high pressure in the same manner as in Example 1,
Impregnate the pitch and then at 450 ° C for 5
Time, coking was carried out. The pitch content of the fired body after the coking was about 3.8% by weight. Furthermore,
When the cylindrical particles after the coking were cut at the center, a white part was observed on the cut surface, but carbon permeated at an area ratio of about 85%, and apparent porosity. It was recognized that even in a fired body having a low P, the pitch was sufficiently introduced into the pores giving the porous structure.

Also, a metal aluminum fine powder was added and contained at a ratio of 20% by weight with respect to the pitch, and the cylindrical fired body fired at a high temperature was impregnated in the same manner as described above. Further, coking was performed at a temperature of 450 ° C. for 5 hours. The carbon amount after the coking was about 3.6% by weight.

In order to investigate the spalling resistance of the cylindrical fired body (Example 2 of the present invention) impregnated and coked with the pitch obtained as described above, the spalling resistance was investigated.
Heating was performed at 0 ° C. for 30 minutes using an electric furnace, followed by rapid cooling in water, and the number of repetitions until the sample was peeled off due to crack generation was determined. The results are shown in Table 3 below. Comparative Example 2 in Table 3 relates to an as-fired cylindrical alumina fired body before impregnation with pitch. The survey of each sample was carried out for 10 samples, and the average value was shown. The numerical values in parentheses indicate variations.

[0043]

[Table 3]

From the results shown in Table 3, the sample according to Example 2 of the present invention is a sample impregnated with a pitch to which metallic aluminum is not added. It is recognized that the spalling property is about twice as good.

Similarly, a crucible erosion test was conducted on the cylindrical fired body subjected to the pitch impregnation coking treatment in order to investigate the corrosion resistance. Specifically, 70 mm
A hole having a diameter of 30 mm and a depth of 35 mm was opened in a magnesia brick having a size of 70 mm x 65 mm, and an erosion agent and a cylindrical fired body sample were placed in the hole, and the electric furnace was heated at a temperature of 1600 ° C for 2 hours. And heated. The erosion agent contained iron: 70% by weight, calcia: 20% by weight, silica:
The one having a basicity: C / S of 2 was used. The sample after the test was cut at the center, and the penetration thickness of the slag was measured. The results are shown in Table 4 below.
It should be noted that Examples 3 and 4 of the present invention in Table 4 relate to samples obtained by using a sample in which metallic aluminum was added to the pitch and a sample in which pitch was not added. Comparative Example 3 relates to a cylindrical high-temperature fired body before pitch impregnation.

In order to investigate the degree of oxidation,
The pitch-impregnated cylindrical fired body according to the present invention obtained above was held at a temperature of 1500 ° C. for 2 hours, cooled, taken out, and the oxidized dimensions were measured.
The results are shown in Table 4 below. In Comparative Example 4, the cylindrical fired body not impregnated with the pitch after the high-temperature firing was crushed into 3 to 1 mm, 1 mm or less, and fine powder, and 40% by weight and 30% by weight, respectively. %, 2
5% by weight, 5% by weight of scale graphite, and 3% by weight of metal aluminum as an antioxidant are kneaded together with a phenol resin, and the pressure is adjusted to 9.8 × 10 with an oil press.
After molding at ⁷ Pa (1000 kg / cm ² ), 200
Dried at a temperature of 24 ° C. for 24 hours and a diameter: 15 mm,
Length: Cut out to 30 mm and used as a sample.

[0047]

[Table 4]

As is clear from the results in Table 4, the cylindrical fired bodies (Examples 3 and 4 of the present invention), which are the metal oxide (alumina) -carbon refractory materials according to the present invention,
The slag penetration thickness and the thickness of the oxide layer are very small, and it is recognized that the slag penetration resistance and the oxidation resistance are excellent. This is probably because, as described above, in the refractory material according to the present invention, carbon is introduced into extremely small pores on the order of microns and dispersed in the material. It is also recognized that the oxidation resistance can be further improved by using metal aluminum in combination.

Example 3 The particle diameter was 50 μm or less and the average particle diameter was about 5 μm.
m alumina particles using a Henschel mixer
The PVA solution was used as a binder to perform spherical granulation to obtain a granulated product having a diameter of about 17 mm. Next, the granulated product is
After drying at a temperature of 0 ° C. for 48 hours, it was fired in a rotary kiln at a temperature of 1750 ° C. to obtain a fired body having an apparent porosity of about 39%. Thereafter, a 65% by weight slurry obtained by finely dispersing carbon black in water was applied to the fired body after firing by using a rotary mixer to about 9.8 ×
It was impregnated under a high pressure of 10 ⁵ Pa (10 kg / cm ² ), allowed to stand naturally for 1 day, and dried at 120 ° C. for 24 hours to obtain a metal oxide-carbon refractory material according to the present invention. Further, using the same fired body and slurry as described above, the pressure during the impregnation operation was increased to about 14.7 × 10 ⁵ Pa (15
kg / cm ² ) or 19.6 × 10 ⁵ Pa (20 kg
/ Cm ² ), and impregnated with carbon black, allowed to stand naturally for one day, and dried at 120 ° C. for 24 hours to obtain a metal oxide-carbon refractory material according to the present invention.

Next, the carbon content of each of the thus obtained various metal oxide-carbon refractory materials (Example 5 of the present invention) was measured.
The spalling resistance of each refractory particle itself was examined, and the results are shown in Table 5 below.

[0051]

[Table 5]

According to the results shown in Table 5, the spalling resistance of the metal oxide-carbon refractory material according to the present invention impregnated with carbon black is the same as that of the pitch impregnated caulked metal oxide-carbon material already examined. A slight decrease is observed as compared with that of the system material, which is considered to be due to the overall lower carbon content. However, an improvement in the non-breakage rate as spalling resistance is recognized as compared with a normal alumina fired body.

Example 4 A thermosetting phenol resin (liquid) was used as a carbon source material for the high-temperature fired body obtained in Example 1 and having an apparent porosity of about 32%. Impregnation under the same conditions as in Example 1 to obtain a fired body having a resin content of about 9% by weight. Then, the spalling resistance of the obtained resin-containing fired body was examined in the same manner as in Example 1. As a result, a good result with a non-breakage rate of 99% was obtained.

Example 5 The particle size was 74 μm or less, and the average particle size was 25 μm.
m magnesia particles using a Henschel mixer
The PVA solution was used as a binder to perform spherical granulation to obtain a granulated product having a diameter of about 22 mm. Next, the granulated product is
After drying at 0 ° C for 48 hours, the mixture was dried for 1 hour using a rotary kiln.
It was fired at a temperature of 800 ° C. to obtain a fired body having an apparent porosity of about 36%. Thereafter, the fired body is heated at a temperature of 190 ° C.
Liquid viscosity: impregnated into a pitch of about 18 centipoise,
Pitch was introduced into the pores of the porous structure to obtain a fired body having a pitch content of about 15% by weight. Thereafter, the fired body impregnated with the pitch was placed in a metal sheath, the periphery thereof was sealed with coke, and coking was performed at a temperature of 450 ° C. for 5 hours. The carbon content after this coking was about 4.5% by weight.

Example 6 The particle size was 74 μm or less and the average particle size was about 20
Using magnesia-alumina spinel particles of μm,
Using a Henschel mixer, the PVA solution was used as a binder to granulate spherically to obtain a granulated product having a diameter of about 20 mm.
Next, the granulated product was dried at a temperature of 120 ° C. for 48 hours, and then fired at a temperature of 1800 ° C. using a rotary kiln, to obtain a fired body having an apparent porosity of about 34%. Thereafter, the fired body is impregnated with tar pitch having a temperature of 205 ° C. and a liquid viscosity of about 18 centipoise, and is introduced into the pores of the porous structure to obtain a fired body having a pitch content of about 16% by weight. Obtained. Then, the obtained pitch impregnated fired body was placed in a metal sheath, the periphery thereof was sealed with coke, and a caulking treatment was performed at a temperature of 450 ° C. for 5 hours. The carbon content of the fired body after such caulking is about 4.
It was 4% by weight. The ratio of magnesia to alumina in the spinel particles used here was about 28:72.

Example 7 The particle diameter was 50 μm or less and the average particle diameter was about 10
Using unstabilized zirconia particles of μm, spherical particles were formed using a PVA solution as a binder in a Henschel mixer in the same manner as in the previous example to obtain a granulated product having a diameter of about 20 mm. Next, the granulated product was dried at 120 ° C. for 48 hours and then fired at a temperature of 1800 ° C. using a rotary kiln to obtain a fired body having an apparent porosity of about 35%. Thereafter, the fired body is heated at a temperature of 210 ° C. and a liquid viscosity of:
By impregnating a pitch of about 19 centipoise and introducing it into the pores of the porous structure, a pitch content of about 15 centipoise is obtained.
By weight, a fired body was obtained. Thereafter, the fired body impregnated with the pitch was placed in a metal sheath, the periphery thereof was sealed with coke, and coking was performed at a temperature of 450 ° C. for 5 hours. The carbon content in the fired body after the coking was about 4.5% by weight.

The refractory material comprising the magnesia-alumina spinel and the zirconia fired body according to the present invention, impregnated with pitch and further subjected to coking, obtained in the above Examples 5 to 7 (Example 7 of the present invention) For 8 and 9), they were each pulverized with a jaw crusher to obtain particles sized to 3.36 to 2.83 mm. Next, an operation of heating 100 g of the sized particles in an electric furnace at 1000 ° C. for 30 minutes and then rapidly cooling in water was repeated three times. When cracks occur in the particles by such an operation, the particles are crushed and refined, but the finely divided particles are removed, and the weight ratio of the uncrushed particles is measured as a measure of the spalling resistance of the particles themselves ( (Non-failure rate%), and the results are shown in Table 6 below. In addition, Comparative Examples 5, 6, and 7 in Table 6 are about the fired bodies before impregnation with the pitch in Examples 5, 6, and 7, respectively, in other words, as fired.

[0058]

[Table 6]

As is apparent from the results in Table 6, the spalling resistance of the fired bodies of Examples 7, 8 and 9 of the present invention impregnated with pitch and subjected to coking was the same as that of ordinary pitch impregnated. It can be seen that it is significantly improved as compared with the non-fired body.

[0060]

As is apparent from the above description, the metal oxide-carbon clinker according to the present invention has excellent resistance to penetration of molten steel and slag, corrosion resistance, and spalling resistance. Since it is a refractory material excellent in chemical properties, such a clinker can be used as it is, or in the case of a refractory such as a brick formed therefrom, the durability (life) can be drastically improved. That is, it exhibits excellent features.

In particular, the metal oxide-carbon clinker according to the present invention can be used not only as a refractory material for providing a refractory brick, but also as a sliding nozzle, a gutter, a refractory for a mixed-iron car, a refractory for continuous casting, and a dipping nozzle. It can be advantageously used as a refractory material that gives a refractory such as
Further, it can be advantageously used as an amorphous refractory, as a castable or various repair materials.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kimito Nakamoto 11-4 Shiogusacho, Seto City, Aichi Prefecture Inside Uchiga Cera Mix Co., Ltd. (72) Inventor Akihiro Donari 4 (72) Inventor Masaki Isomura 11-4 Shiogusa-cho, Seto City, Aichi Prefecture Inside Uchiga Sera Mix Co., Ltd.

Claims (6)

[Claims] 1. A porous sintered body of a metal oxide is impregnated with a carbon source material so as to be introduced into pores giving the porous structure, or the impregnated material is baked or coked. A metal oxide-carbon clinker characterized by being subjected to the following. 2. The metal oxide-carbon clinker according to claim 1, wherein the carbon source material is a pitch, and the pitch is heated and liquefied to impregnate the sintered body. 3. The metal oxide according to claim 1, wherein the carbon source material is carbon fine powder such as carbon black, coke, mesophase carbon, and the carbon fine powder is impregnated into the sintered body in a slurry state. Product-carbon clinker. 4. The carbon source material is an organic polymer material such as a phenol resin, a furan resin, a polyacrylonitrile, a melamine resin, and an epoxy resin, and the organic polymer material impregnates the sintered body in a liquid form. The metal oxide-carbon clinker according to claim 1, wherein the clinker is used. 5. The carbon source material is mixed with a metal antioxidant such as aluminum, aluminum-magnesium alloy, magnesium, silicon, etc., and in the form of the resulting mixture or in the form of a slurry. The metal oxide-carbon clinker according to any one of claims 1 to 4, wherein the sintered body is impregnated in the state. 6. A refractory comprising the clinker according to any one of claims 1 to 5 as a refractory material.