JPH06287072A - Resin-bound carbon-containing castable refractory - Google Patents

Abstract

PURPOSE:To provide a resin-bound carbon-containing castable refractory, excellent in filling properties and capable of forming a stable connected structure while containing scaly or fibrous carbon having great effects on improvement in spalling resistance due to a high thermal conductivity or strength characteristics. CONSTITUTION:This resin-bound carbon-containing castable refractory is composed of a refractory powder part and a resin liquid part. In this refractory, the refractory powder part is composed of pellets and a refractory material and the pellets are prepared by press forming a mixture composed of at least 5wt.% scaly graphite and/or carbonaceous fiber and the remainder of a refractory material with a resin of the same kind as that of the resin liquid part as a binder and have 3-12% porosity. The weight ratio of (the total carbon content of the pellets)/(the total carbon content of the refractory powder part) is >=0.5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a blast furnace gutter, a mixed piggy car, a converter, an electric furnace, a degassing device, a hot metal / steel container for iron making such as a tundish, a refining furnace, and other kilns used at high temperatures. The present invention relates to a resin-bonded carbon-containing amorphous refractory used for lining and lining of a furnace.

[0002]

2. Description of the Related Art Conventionally, amorphous refractory materials such as castables, plastics, stamp materials and spray materials have been selected and widely used according to various applications. In particular, low-cement castables have good filling properties and can contain a small amount of impure inorganic binder components, so they exhibit excellent corrosion resistance comparable to that of bricks and lined hot metal / steel containers and various refining furnaces.・ The number of cases where it is applied to lining is increasing. However, these conventional types of materials need to use water as a liquid component in order to provide moldability.

On the other hand, in the field of refractory bricks, carbon-bonded bricks containing a binder containing carbon and forming carbon by heating, particularly refractory using scaly graphite, suppress the infiltration of slag components, Since it has excellent spalling resistance,
In particular, it has come to be widely used for severely eroded applications such as refining furnaces.

In recent years, in the field of amorphous refractories as well, carbon-containing amorphous refractories, which use various resins as binders and form carbon bonds by heating, have been developed, but are still penetrating the market. Is in a difficult situation to say.

An example of the prior art regarding amorphous refractory containing carbon is shown below. For example, Japanese Unexamined Patent Publication (Kokai) No. 57-92581 discloses a basic castable refractory which uses MgO and graphite and uses a condensed sodium phosphate binder as a binder and high alumina cement. It shows that the corrosion resistance is improved by adding 5 to 35% of graphite. However, when a mixture containing graphite is added and mixed with water, the graphite is difficult to wet with water, and when graphite having a flat shape such as scaly graphite is used, the dispersibility is poor and the movement of the material Workability is significantly reduced. Therefore, in reality, it is necessary to increase the amount of added water, and as a result, only a construction body having a low packing density can be obtained. Further, in the case of a construction body having a low packing density and a high porosity, the added graphite is often oxidized during the heating process, which rather lowers the corrosion resistance.

Japanese Unexamined Patent Publication (Kokai) No. 59-227779 proposes a basic refractory containing 15% to 60% of coarse particles of 10 to 90 mm, which is composed of a carbonaceous material of 2% or more and the balance of a basic material. . Since coarse particles contain carbon, slag intrusion into and around the coarse particles is reduced, and the coarse particles and the matrix are not integrated, which is said to be effective for crack prevention. However, since the coarse particles contain carbon, when they are used by kneading with water, they are not well compatible with the coarse particles, and therefore, they are inevitably compatible with the water-based binder. Is insufficient, and a strong connective tissue cannot be obtained.

Japanese Unexamined Patent Publication No. 3-150272 discloses Japanese Unexamined Patent Publication No. Sho 59-22.
It proposes an improvement based on a similar idea to the 7779 publication.
This is a basic casting in which a mixture of scaly graphite and a refractory material added with a binder is molded with a briquette machine to 10 to 60 mm and the heat-treated granule is blended with 10 to 60% of the whole aggregate. It is a material. Briquette has a low air permeability, is highly resistant to oxidation, and has low friction on the surface of the granulated product, so it can reduce the amount of water applied. In addition, the basic casting material according to this technique is said to have solved the problem of crack generation due to thermal expansion stress. However, this technique is also disclosed in JP-A-59-22.
Like the 7779 publication, it is a casting material that uses a mixture of carbon-containing granules, and it is necessary to use water as a liquid component in the same manner as in the past, and it is necessary to wet the carbon-containing granules and water. The poorness is the same, and therefore, only a construction body having a weak bonding force can be obtained. When used in an actual furnace, when the granules are exposed on the surface to be used, the granules have a weak bond with the surroundings, so they easily slip off and have a drawback that the damage progresses rapidly. Yes, practically very difficult. In any case, it should be considered that there are major problems in applying or molding the carbon-containing material with water and a binder that requires water.

On the other hand, Japanese Unexamined Patent Publication (Kokai) No. 61-124513 discloses a non-water-based amorphous material containing magnesia-based coarse aggregate, which is a stud formed by projecting a part of a converter wear brick into a stud. . Further, JP-A-63-215572 discloses,
Basic raw material 70-95%, carbonaceous raw material 5-30%, and basic coarse particles of magnesia, dolomite, etc., which are larger than 1.5 times the maximum particle diameter of the refractory material and 30 mm or less,
Disclosed is a refractory composition containing 130% and 4-15% thermosetting resin. These all contain carbon,
In addition, it is an amorphous refractory that uses a binder that forms a carbon bond by heating. Since a resin, tar, etc. are used as the binder, the wettability with respect to carbon materials is good, but when flat carbon such as scaly graphite is used, the shape of graphite is similar to that of other materials, like water-based materials. Since it hinders the movement of particles, the workability is greatly reduced, and sufficient filling properties cannot be obtained. Further, by adding coarse aggregate or coarse particles, it is intended to improve structural stability and corrosion resistance, but basic materials such as magnesia and dolomite basically have a large coefficient of thermal expansion, The volume fluctuates greatly according to the temperature change, and in particular, when large particles are used, a gap is generated due to the difference in thermal expansion between the surrounding carbon bond structure. For this reason, under use conditions with temperature changes, the addition of coarse aggregate or coarse particles has no effect of structural stabilization.

[0009]

As described above, when an amorphous refractory material containing carbon cannot be applied, a large amount of energy cannot be applied as in a high pressure press when forming a brick, so that a binder for carbon cannot be applied. Since the wettability and the shape of carbon itself have a great influence on the workability of work, that is, the formability, it is difficult to obtain stable and good filling properties. Further, even if a large amount of refractory material particles are mixed and used, there is a problem in bondability, which is not practically reliable.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a scale that is highly effective in improving spalling resistance and strength characteristics due to high thermal conductivity. While containing carbon in the form of fibers and
It is an object of the present invention to provide a resin-bonded carbon-containing amorphous refractory which is excellent in filling property and can form a stable connective structure.

[0011]

A resin-bonded carbon-containing amorphous refractory according to the present invention is a resin-bonded carbon-containing amorphous refractory consisting of a refractory powder part and a resin liquid part. Is composed of pellets and a refractory material, and the pellets are pressed with a mixture of at least 5% by weight of scaly graphite and / or carbonaceous fibers and the remainder being a refractory material using a resin of the same type as the resin liquid part as a binder. Molded porosity of 3-12%, and (total carbon amount of pellets) /
The weight ratio of (total carbon content of the refractory powder part) is 0.5 or more.

[0012]

In the carbon-containing resin-bonded amorphous refractory of the present invention (hereinafter simply referred to as amorphous refractory), it is necessary to secure the wettability between the carbonaceous material and the binder in order to obtain a stable bond structure. Considering this to be a necessary condition, the resin liquid part is used as the liquid component that gives the binder and the moldability. The resin liquid part used for the amorphous refractory material of the present invention is required to have a carbon residue ratio as high as possible in order to form a carbon bond after heating, similarly to the characteristics required for the conventional carbon-containing refractory material. Also,
It must have good wettability with respect to the carbonaceous material. In this respect, phenol resin, furan resin,
Epoxy resins, melamine resins, urea resins, resorcinol resins, furfuryl alcohol polymers and the like can be used. Among them, phenol resins are most preferable, and both resol type and novolac type can be applied satisfactorily.

For the resin liquid part, a liquid whose viscosity is adjusted to an optimum value should be used according to the construction method of various types of irregular refractory materials. For example, in cast molding, in order to improve fluidity, a resin liquid having a viscosity as low as possible is preferable, while in a stamp molding material, one having an appropriately high viscosity is easier to apply,
It is preferably about 50 centipoise or more. In any case, the viscosity of the resin liquid part can be adjusted by changing the type and addition amount of the solvent of the resin. As the solvent, generally known alcohols, glycols and the like can be used. However, it should be noted here that if the amount of solvent added to adjust the viscosity is increased too much, the solvent will volatilize and burn due to heating, so the amount of residual carbon after heating will decrease and the bond strength will decrease. Cause a decrease in Therefore, it is preferable that the concentration of the resin component in the resin liquid is at least 35% or more.

When it is necessary to cure the resin at room temperature after construction depending on the conditions of use, it is necessary to add a curing agent for curing the resin at room temperature. As the curing agent, an acidic substance such as paratoluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid, sulfamic acid, oxycarboxylic acid, amino acid, or various esters can be used. These hardeners are added to and mixed with the refractory powder part or mixed with the resin liquid part depending on their properties, that is, powder or liquid, direct reaction with resin or secondary reaction with the resin. Determined and used.

In the case where the work is carried out at a temperature of about 100 to 200 ° C. or when it is heated and cured after the work, a thermosetting type resin such as a resole type phenol resin is used, or a thermoplastic resin is used. A curing agent that imparts thermosetting property to the novolac type phenolic resin, such as hexamine, may be added. Further, when applying at a high temperature, it is possible to use only a thermoplastic resin without adding a curing agent.

In the amorphous refractory of the present invention, the refractory powder part contains at least 5% by weight of scaly graphite and / or carbonaceous fiber, and the balance is made of refractory raw material. The present invention is characterized in that pellets that are pressure-molded using a resin of the same type as the binder resin solution and that have a porosity of 3 to 12% are blended.

As described above, even if the resin liquid part which is easily wetted by carbon is used as the binder, the bondability between the binder and the carbonaceous material is improved by itself, but the workability as an amorphous refractory is not improved. Hardly improved. Since scaly graphite and / or carbonaceous fibers have a large surface area as compared with particles such as refractory materials, a large amount of liquid is required to cover the surface of each particle. Further, since the shape is flat or fibrous, it is difficult to knead with an ordinary mixer and it is difficult to disperse it uniformly, and the movement of the material particles is obstructed even at the time of construction to reduce the filling property. Therefore, in the amorphous refractory of the present invention, the scaly graphite and / or the carbonaceous fiber, which is a cause of lowering the workability of the construction, is added to the refractory raw material in the form of pellets which can be treated as granules. is there.

A compound containing no scaly graphite and / or carbonaceous fiber, or when the amount added is less than 5% by weight,
It is not necessary to pelletize and mix as in the present invention. Unless the pellet contains at least 5% by weight of scaly graphite and / or carbonaceous fiber, the effect of the present invention is not apparent. In addition to scaly graphite and / or carbonaceous fibers, the pellets include artificial graphite, coke, and carbonaceous materials.
It is also possible to mix and use carbon such as carbon black and a material such as resin powder or pitch powder that forms carbon by heating.

The elements other than the carbonaceous material constituting the pellets are refractory raw materials. The refractory raw material used for the pellets is not particularly limited, but a refractory raw material having the same quality as the main refractory material constituting the entire amorphous refractory is preferable. For example, when the overall amorphous refractory is alumina-carbonaceous, the refractory raw material used in the pellet is preferably one mainly composed of alumina, and when it is magnesia-carbonaceous, it is mainly composed of magnesia. Are preferred. In order to stabilize the bond strength between the refractory powder parts other than the pellets and the pellets, take into consideration the differences in the characteristics of the two and take care not to cause unnecessary distortion, etc., when used at high temperatures. Should be.

In forming the pellets, it is an important element of the present invention to use as binder a resin of the same type used to bind the entire amorphous refractory.
That is, when the binder used in the pellet is different from the resin liquid part which is the binder of the entire amorphous refractory, the entire amorphous refractory shows that the binding is not continuous inside and outside the pellet. It was also experienced that the bond between the pellet and the surrounding was broken during heating or at high temperature due to the difference in properties due to the difference in bonding mode, for example, difference in thermal expansion / contraction properties. Therefore, by molding the pellets using the same type of resin as the binder that binds the entire amorphous refractory as the binder, the infiltration and familiarity of the resin liquid part to the pellets becomes good at the time of construction, and heating It was possible to maintain a stable bond as a whole construction body in both warm and high temperature use conditions. Incidentally, here, the same type of resin means that, for example, a phenol resin solution is used for the resin liquid part, and when the binder for the entire amorphous refractory is used, the phenol resin is also used for the pellet binder. It does not need to be considered so much regarding the characteristics of the resin such as whether it is a liquid or a powder or a difference in viscosity.

As a result of various studies on the method of forming pellets, unless the method of at least pressurizing and granulating, the mixed material containing scaly graphite and / or carbonaceous fibers is uniformly and densely pelletized. It has proven difficult to mold. The type of molding machine that can be used depends on the material that constitutes the pellets, especially the particle size of the refractory raw material that cannot be deformed, and the required size of the pellets. Machine,
It is preferable to use a briquette-type granulator or an extruding type disk pelleter that is pressed with high pressure. What is important is the porosity of pellets molded using such granulators.

Although the porosity can be adjusted to 1.5 to 2% depending on the compounding and molding method of the pellets, the amorphous refractory material of the present invention uses pellets having a porosity of 3 to 12%. . Considering the pellets themselves, it is judged that the smaller the porosity, the better the corrosion resistance, the higher the strength, and the better. However, in the entire amorphous refractory material, the pellets behave as particles like other refractory materials. Therefore, if the porosity of the individual pellets is too low, the resin liquid part, which is the binder, cannot be sufficiently infiltrated into the pellets when it is applied as a whole of an irregular shaped refractory, and it stops at surface adhesion and becomes strong. Inability to form connective tissue. On the other hand, when the porosity of the pellet exceeds 12%, the strength of the pellet itself becomes insufficient and cracks may occur during kneading. Further, in the case of a pellet having a high porosity, it is meaningless to form the pellet in order to cover the poor filling property due to the addition of scaly graphite or carbonaceous fiber. For this reason, the porosity of the pellet is preferably 3-12%.

The size of the pellets should be changed according to the method of construction of the irregular refractory, but the maximum length is usually 3
The thing of about 100 mm is used. With pellets having a size of less than 3 mm, it is difficult to obtain pellets having stable physical properties with large variations in porosity. The maximum size depends on the size of the construction body on which the amorphous refractory of the present invention is constructed,
If it exceeds 100 mm, it is difficult to knead and is not practical. Most preferably, the size is about 4 to 50 mm. As with the other refractory materials, it is preferable to mix and use two or more types of pellets having different sizes in consideration of the particle size composition of the entire amorphous refractory material. However, since the pellet size may be limited to some extent depending on the particle size of the raw material scaly graphite and the length of the carbonaceous fiber, it may be better to concentrate the pellets of a specific size.

The pellets used for the amorphous refractory material of the present invention need to be in the shape as it is. What is granulated by crushing after being molded into a large shape is not preferable because one end of scaly graphite or carbonaceous fiber appears on the surface of the crushed particles and the workability is deteriorated.

The refractory powder portion of the amorphous refractory material of the present invention is
Basically, it consists of a refractory material, a carbonaceous material, and other additives, similar to the conventional carbon-containing amorphous refractory material. Here, in the amorphous refractory of the present invention, the pellets are mixed and used as a kind of carbonaceous material that can be treated as a granular material like the refractory material, and (total carbon amount of pellets) /
The weight ratio of (total carbon content of the refractory powder part) is 0.5 or more, that is, 50% or more of the total carbon content of the refractory powder part is supplied from the pellet so that the scale-like particles in the pellet are supplied. The blending amount of graphite and / or carbonaceous fiber and other carbonaceous material and the blending amount of pellets are adjusted.

FIG. 1 shows the results of a trial experiment on an amorphous refractory material using scaly graphite as a carbon source and magnesia as a refractory material. 3% of resole type phenolic resin liquid was added to a mixture consisting of 20% of scaly graphite and 80% of seawater magnesia clinker whose particle size was adjusted to 2 mm or less, and kneaded with a briquetting granulator to obtain pellets having a maximum length of about 10 mm. It was molded and heat-treated at 150 ° C. for 24 hours. The porosity of the pellet was 5.1% as an average value of n = 5. Seawater magnesia clinker was used as the refractory material forming the refractory powder portion, and the particle size was adjusted to a particle size of 6 mm or less. Pellets, magnesia clinker, and scaly graphite were mixed to prepare and mix a refractory powder part having a total carbon content of 15%. However, since pellets of one type were used in this experiment, it was necessary to use magnesia for the fine powder in order to make a casting compound, and the maximum addition amount of pellets was 75%. A resole-type phenol resin solution was added and kneaded to this, and the mixture was subjected to vibration pouring to prepare a sample of 40 × 40 × 160 mm. Apparent porosity and three-point bending strength were measured after heating the sample in a non-oxidizing atmosphere at 1000 ° C. for 3 hours. Of the total carbon content of 15% in the refractory powder portion, the carbon content ratio supplied from the pellet is plotted on the horizontal axis, and the porosity and bending strength are plotted on the vertical axis in FIG.

When the pellets are not used at all, the porosity of the sample is close to 50%. When the weight ratio of (total carbon amount of pellets) / (total carbon amount of refractory powder portion) is about 0.5 or more, the porosity can be significantly reduced. The weight ratio is about 0.6
In the range of not less than%, a construction body having a low porosity can be stably obtained. A high bending strength is obtained in a region where the weight ratio is about 0.5 or more, which is symmetrical with the change in porosity. As is clear from this experiment, if the carbon source necessary for the entire amorphous refractory is used as it is with the refractory material, in the case of flat carbon such as scaly graphite, the filling property at the time of molding is obtained. Therefore, it is possible to obtain only a construction body having high porosity and low strength. That is,
It can be seen that when the weight ratio of (total carbon amount of pellets) / (total carbon amount of refractory powder portion) is about 0.5, the effect of lowering porosity and improving strength is remarkable.

The refractory material other than the pellets in the refractory powder portion of the amorphous refractory material of the present invention is not particularly limited, but a refractory material having properties similar to the refractory material forming the pellets is preferable. The type of refractory material should be selected according to the environment of the application in which the amorphous refractory of the present invention is used, for example, the operating temperature, atmospheric components, slag components, etc., and the relative acidity of blast furnace gutters and mixed pig trucks. For applications exposed to strong slag, SiO ₂ , ZrO ₂ , Al ₂ O ₃ ,
Acidic or neutral refractory materials mainly composed of SiC are good,
On the other hand, a basic or neutral refractory material mainly containing MgO, CaO, Al ₂ O ₃ , Cr ₂ O ₃ or the like is suitable for a slag having a relatively high basicity such as a converter or an electric furnace. .

The total amount of carbon in the refractory powder part consisting of pellets and refractory material is preferably at least 5% or more. 5
%, The effect of carbon addition is small, while practically 3
An amount of 5% or less has a sufficient effect. Further, these refractory materials should be adjusted and used so as to have an appropriate grain size composition according to the respective construction methods of the irregular refractory material. For example, in the case of vibration pouring construction, it is common to place importance on fluidity and to make a continuous particle size from a coarse particle to a fine powder area. Other construction methods include stamping, vibration pressurization, spraying, trowel coating, press-fitting, etc., but it is preferable to use a refractory material whose particle size is adjusted in consideration of the respective workability and filling property. In order to improve the fluidity and the filling property, it may be necessary to blend the particle size with the addition of ultrafine powder.

In some cases, it is preferable to add a small amount of carbonaceous material to the refractory powder portion of the amorphous refractory material of the present invention in addition to the pellets. As described above, it is better not to mix scaly graphite or carbonaceous fiber from the aspect of filling property, but since the pellet is just a grain and not a powder, the total amount of the carbonaceous material depends on the pellet. In this case, in the fine powder matrix part, there is no carbonaceous material other than the carbon content due to the carbonization of the resin liquid part which is the binder, and the thermal interaction between the pellets and
There may be a difference in mechanical properties, which may lead to an unfavorable state. This is particularly remarkable in an amorphous refractory material containing a large amount of total carbon such as 20% or more. Therefore, the workability of the refractory powder part, that is, as a carbonaceous material that does not significantly hinder the moldability, artificial graphite, coke, carbon black, etc., and scale graphite coated with pitch or resin, etc. It is preferable to add it in the form of particles by pretreatment such as forced mixing. The addition amount at this time is (total carbon amount of pellets) /
The weight ratio of (total carbon content of the refractory powder part) is within the range of 0.1 to 0.5, that is, about 10 to 5 of the total carbon content of the refractory powder part.
When it is 0%, the difference between the pellet and the fine powder matrix portion is practically no problem.

It is possible to add a small amount of a surfactant to the refractory powder part of the amorphous refractory material of the present invention in order to enhance the dispersibility of fine powder. Further, in order to stabilize the carbon bond due to the carbonization of the resin after heating and to improve the hot strength, metal powder or alloy powder of Al, Si, Mg, etc., SiC, B ₄ C, CaB ₆ etc. Carbides, borides, etc. can also be added. In order to reinforce the carbon bond due to carbonization of the resin liquid part, powdered resin, pitch,
It is also possible to add a small amount of powdery material such as mesophase carbon that produces carbon by heating. In addition, these surfactants, metal powder, alloy powder, carbide, boride,
It is also possible to add a small amount of carbon-producing material to the pellet.

[0032]

Example As shown in Table 1, 6 kinds of pellets were prepared. 1 to 4 are pellets used for the amorphous refractory of the present invention, 5 is a pellet using sodium phosphate rather than resin as a binder, and 6 is a particle size of magnesia clinker and a material supply rate to a briquette. Therefore, the porosity was set to 1.8%.

[0033]

[Table 1]

Using these pellets, an irregular refractory material shown in Table 2 was prepared and a construction body was formed by each construction method.
The products 1, 2 and 5 of the present invention were subjected to pouring while applying vibration, and the product 3 of the present invention was applied while being pressed by the own weight of the diaphragm while applying vibration to obtain a molded body. Molded body 110
After heating at ℃ for 24 hours, it was cut into 40 × 40 × 160 mm and used as a sample. The product 4 of the present invention is hot pouring as a forming method, but it is a baking material used for so-called hot repair, and is cast into a refractory sheath at a temperature of 1000 ° C. and then cooled 40 × 40 × A sample was cut out to 160 mm. Comparative products 6 to 8 are all products of the present invention 1, 2 and 5
Casting was performed while applying vibration in the same manner as in. Apparent porosity and bending strength were measured after heat-treating these samples at 1000 ° C. for 3 hours in a reducing atmosphere. Also, 14
A comparative test of hot bending strength at 00 ° C was performed.

[0035]

[Table 2]

As is clear from Table 2, all the products of the present invention have low porosity and high strength as an amorphous refractory containing carbon. On the other hand, Comparative product 6 is an amorphous refractory that does not use pellets, but has a significantly high porosity and low strength. Comparative product 7 was prepared by adding pellets using sodium phosphate as a binder, and using alumina cement as a binder for an amorphous refractory material, although the porosity after heating at 1000 ° C was low, the strength was high. Is extremely low. Comparative product 8
Is a pellet having a low porosity, and the weight ratio of (total carbon amount of pellet) / (total carbon amount of refractory powder part) is 0.
It is an amorphous refractory material of 417 and has a considerably high porosity and low strength.

[0037]

The scaly graphite and / or the carbonaceous fiber is a very effective material for improving the spalling resistance and strength of refractory materials, and is widely used in refractory bricks. In the case of a standard refractory, it was difficult to obtain a satisfactory filling property or strength of the construction body due to a decrease in formability. By the amorphous refractory of the present invention,
Even if a large amount of such scaly graphite or carbonaceous fiber is added and used, it is possible to easily obtain a construction body having excellent workability, low porosity, and high strength after heating and hot. In this way, while containing the scaly graphite and carbonaceous fiber, since a dense and high-strength construction body can be obtained, due to the property that carbon has poor wettability to slag, there is little slag infiltration and excellent slag erosion resistance. Amorphous refractories are now available.

[Brief description of drawings]

[Fig.1] (Total carbon content of pellets) in amorphous refractory /
It is a figure which shows the weight ratio of (the total carbon amount of a refractory powder part), the porosity (%), and the relationship of bending strength.

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[Procedure amendment]

[Submission date] April 27, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

When the pellets are not used at all, the porosity of the sample is close to 50%. When the weight ratio of (total carbon amount of pellets) / (total carbon amount of refractory powder portion) is about 0.5 or more, the porosity can be significantly reduced. In the region where the weight ratio is about 0.6% or more, a construction body having a low porosity can be stably obtained. A high bending strength is obtained in a region where the weight ratio is about 0.5 or more, symmetrically with the change in porosity. As is clear from this experiment, if the carbon source necessary for the entire amorphous refractory is used as it is with the refractory material, in the case of flat carbon such as scaly graphite, the filling property at the time of molding is obtained. Therefore, it is possible to obtain only a construction body having high porosity and low strength. That is, it can be seen that when the weight ratio of (total carbon amount of pellets) / (total carbon amount of refractory powder portion) is about 0.5 or more , the effect of lowering porosity and improving strength is remarkable.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

In some cases, it is preferable to add a small amount of carbonaceous material to the refractory powder portion of the amorphous refractory material of the present invention in addition to the pellets. As described above, it is better not to mix scaly graphite or carbonaceous fiber from the aspect of filling property, but since the pellet is just a grain and not a powder, the total amount of the carbonaceous material depends on the pellet. In this case, in the fine powder matrix part, there is no carbonaceous material other than the carbon content due to the carbonization of the resin liquid part which is the binder, and the thermal interaction between the pellets and
There may be a difference in mechanical properties, which may lead to an unfavorable state. This is particularly remarkable in an amorphous refractory material containing a large amount of total carbon such as 20% or more. Therefore, the workability of the refractory powder part, that is, as a carbonaceous material that does not significantly hinder the moldability, artificial graphite, coke, carbon black, etc., and scale graphite coated with pitch or resin, etc. It is preferable to add it in the form of particles by pretreatment such as forced mixing. In any case, charcoal added separately from pellets
Amount of quality material, the weight ratio of (pellet total carbon content) / (total carbon content of the refractory powder unit) 0. Should be 5 or more
It is

Claims (2)

[Claims] 1. A resin-bonded carbon-containing amorphous refractory comprising a refractory powder part and a resin liquid part, wherein the refractory powder part is composed of pellets and a refractory material, and the pellets are at least 5% by weight of scale. Porosity 3 to 12 obtained by pressure molding using a resin of the same type as the resin liquid part as a binder in a mixture of graphite and / or carbonaceous fibers and the remainder being a refractory material.
%, And the weight ratio of (total carbon amount of pellets) / (total carbon amount of refractory powder portion) is 0.5 or more, and a resin-bonded carbon-containing amorphous refractory material. 2. The resin-bonded carbon-containing amorphous refractory material according to claim 1, wherein the maximum size of the pellet is 3 to 100 mm.