JP2003171182A - Carbon-containing unburned brick - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environmentally compatible high durability carbon- containing unburned brick which is free from the occurrence of odors and fumes that becomes a problem from the viewpoint of the improvement of working environments, regional environments and the earth environment when it is heated, exhibits resistance to oxidation damage having been one of problems up to now and has excellent spalling resistance. <P>SOLUTION: This carbon-containing unburned brick is characterized in that a mixture of raw materials including a refractory raw material and a carbonaceous raw material contains an inorganic binder and does not generate odors and/or fumes at the heat treatment process. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to holding molten metal,
Regarding carbon-containing unfired bricks used for transportation, treatment, and control, in particular, odor and smoke are not generated during the heating process,
The present invention also relates to an environment-friendly high durability carbon-containing non-fired brick having excellent oxidation resistance and spalling resistance.

[0002]

_2. Description of the Related Art Al ₂ O ₃ -C bricks, Al ₂ O ₃ -SiC are used as refractory for lining and casting for holding, transporting and treating molten metal.
-C bricks, Al ₂ O ₃ -MgO-C bricks, carbon-containing bricks, such as MgO-C bricks are widely used. This kind of carbon-containing brick has excellent corrosion resistance and spalling resistance due to the characteristics of carbon, such as "slag resistance to wetting and high thermal conductivity".

However, since carbon has a property of being difficult to sinter, a lot of studies have hitherto been made on a binder (a binder for forming a connective structure of a carbon-containing brick).
As a method of forming a bond structure of carbon-containing bricks by various improvement studies, formation of carbon bonds and ceramic bonds is currently generally practiced.
Carbon bond is a method of forming a connective structure with residual carbon content derived from an organic binder, and ceramic bond is a method of forming a connective structure by reaction between refractory aggregates and a metal additive.

As a means for forming a carbon bond,
In the carbon-containing brick, an organic binder is used as a binder, and a phenol resin is generally frequently used. Since the phenol resin has a high residual carbon rate, it can form a carbon bond having a high density, and has a characteristic of excellent strength retention after high temperature firing. In addition, since phenol resin has good wettability to carbon raw materials such as graphite and is highly adhesive, it has excellent kneadability and moldability, and has high workability such as high expression strength after drying treatment. Since it also has, it has been widely adopted.

[0005]

However, when the phenol resin is used as the binder, the following problems occur. Phenolic resin undergoes thermal decomposition during the heating process and produces various decomposition gases (Reference: Refractories)
[33] 64-81, 1981). These decomposed gases contain a large amount of aromatic organic compounds and have an unfavorable effect on the human body. Further, among these components, phenol, cresol, xylenol and the like have a particularly strong irritating odor, which causes the generation of odors and causes environmental deterioration.

As a method of improving this phenomenon, refractory materials are preliminarily (preliminarily) used at a temperature at which the thermal decomposition of the phenol resin is completed.
A manufacturing method in which heat treatment is performed has been proposed. But,
In this method, although it is possible to prevent the generation of organic gas when the refractory is heated, in the manufacturing process of the carbon-containing brick, since the same pyrolysis gas as the above is generated, "the environment of odorous organic gas It is not the fundamental means of "solving the release to". In addition, there are many technical and economical problems such as high cost of heat treatment at high temperature and increase of energy consumption for brick production.

[0007] Therefore, until now, although the problem that the organic gas which is not preferable to the environment and the human body is released, there is no fundamental and effective means for solving the problem. It is the current situation that non-fired bricks containing are widely used.

On the other hand, the carbon produced by the thermal decomposition of the phenolic resin is glassy carbon and is said to have poor oxidation resistance and spalling resistance. Therefore,
The carbon-containing brick using a phenol resin as a binder has a problem in obtaining sufficient oxidation resistance and spalling resistance.

In order to solve the above-mentioned problems with respect to the oxidation resistance and spalling resistance, various improvements have been studied in the past. In order to improve the oxidation resistance, many methods have been proposed for suppressing oxidation of carbon by adding a metal, an alloy, or an easily oxidizable additive such as boride or carbide. In order to improve spalling resistance, methods such as carbon bond strengthening by addition of pitch, addition of fibers, or introduction of fine voids into the structure have been proposed.

However, even by these methods, it cannot be said that the oxidation resistance and the spalling resistance of the carbon-containing bricks are sufficiently improved, and further improvement is desired. For example, Japanese Patent Laid-Open No. 9-221370 discloses a method for producing a carbon-containing unfired brick having excellent spalling resistance, but has problems such as poor oxidation resistance due to high porosity and the like. is there.

As a means for solving these problems, the inventors of the present invention did not generate an odorous organic gas when exposed to heat, and were excellent in both oxidation resistance and spalling resistance. The present invention has been completed as a result of intensive research conducted for the purpose of developing “fired brick”.

That is, the object (object) of the present invention is to eliminate the generation of odors and smoke, which are problems when heated, from the viewpoint of improving the working environment, the local environment and the global environment. The oxidative damage that was the problem of
Another object of the present invention is to provide an environment-friendly high durability carbon-containing non-fired brick which is also excellent in spalling resistance.

[0013]

The carbon-containing unfired brick according to the present invention has means (structure) for solving the above-mentioned problems.
As "as a raw material blend containing a refractory raw material and a carbonaceous raw material, the raw material blend contains an inorganic binder and does not generate odor and / or smoke during the heating process" (claim 1) Characteristically, with this configuration, it is possible to provide the "environmentally friendly high durability carbon-containing non-fired brick" which is the subject (objective).

The inorganic binder "includes a substance forming a silicate bond and / or a substance forming a phosphoric acid bond" (claim 2) or "comprising cement" (claim 5). Is characterized by. And
The material forming the silicate bond is sodium silicate,
At least one selected from potassium silicate, lithium silicate, ethyl silicate, colloidal silica
(Claim 3) The substance forming the phosphate bond is sodium phosphate or aluminum phosphate (Claim 4), and the cement is alumina cement or magnesia cement (Claim 6). To do.

Further, in the carbon-containing unfired brick according to the present invention, the raw material composition contains a metal for imparting strength (claim 7), and the metal is silicon, aluminum, magnesium, titanium, chromium. , One or more selected from zirconium or alloys thereof
By characterizing (claim 8), by blending such a metal, it is possible to impart the required strength to the brick.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. First, the effect of the inorganic binder used in the present invention will be described. As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that organic binders such as phenolic resins conventionally used as binders are used. It has been found to be very effective to use an inorganic binder as a binder without using it.

In the present invention, since an organic binder is not used as a binder and an inorganic binder is used, organic gas is not generated even when the brick is unfired when it is heated. Therefore, when exposed to heat, the generation of odors and smoke is completely prevented, the release of undesired organic gas to the human body is eliminated, the working environment is improved, and harmful aromatic compounds are released to the environment. To be prevented.

Further, the inorganic binder used in the present invention produces a substance having a low melting point in the brick structure. Then, the generated low-melting-point substance diffuses into the brick structure, coats the carbon raw material, and exerts an effect of suppressing carbon oxidation.
As a result, the oxidation resistance of the carbon-containing brick is improved. Further, by generating the low melting point substance, creep deformability is generated at high temperature, and the thermal stress is relaxed. This has the effect of improving spalling resistance.

Next, the function and effect of the inorganic binder in the present invention will be described in comparison with the conventional "inorganic binder use example".

The application of an inorganic binder to a refractory has been conventionally carried out for refractory bricks containing no carbon raw material. For example, JP-A-50-107010 and JP-A-200107 / 200.
Japanese Patent Laid-Open No. 0-119061 and the like disclose examples of use of sodium silicate. However, the inorganic binder in these examples
The purpose of using (sodium silicate) is to ensure good kneading property, formability, strength of the molded body, and strength after heat treatment for refractory bricks that do not contain carbon raw materials, and good workability in manufacturing refractory bricks. Is to get. Therefore, it is completely different from the purpose of use such as "the effect of preventing the generation of odorous gas, the effect of preventing the oxidation of carbon, the effect of improving the spalling resistance", which is a feature of the present invention, and the "carbon It does not suggest the action and effect of the inorganic binder that is particularly exerted when applied to the contained unfired brick ”.

As an example of application of an inorganic binder to a carbon-containing brick, for example, Japanese Patent Application Laid-Open No. 54-11113 discloses "Phenolic resin or modified phenolic resin is a refractory raw material mainly composed of carbon material or silicon carbide material. Method of adding hydroxide of alkaline earth metal, alkali metal silicate, alkali metal aluminate, etc. when kneading in
Is disclosed.

Also in this application example, the purpose of using the inorganic binder is to prevent swelling of the raw angle at the time of depressurizing the molding, floating of the coarse grain portion, occurrence of lamination and cracking, etc.
It is intended to improve workability and plays an auxiliary role when an organic binder (phenol resin or modified phenol resin) is used as a main binder. Therefore, the effect of preventing the generation of odorous gas, the effect of preventing the oxidation of carbon, and the effect of improving the spalling resistance, which are the features of the present invention,
It is completely different from the purpose of use and does not suggest the purpose and effect of using the inorganic binder in the present invention. Moreover, in this application example, it is assumed that the "organic binder" is used as the binder,
Incorporating an "inorganic binder" into this,
The present invention is different from the present invention on the premise that "odor and / or smoke are not generated in the process of being heated, that is, an organic binder such as a phenol resin is not mixed".

Further, as an example of using an inorganic additive in a carbon-containing brick, for example, in Japanese Patent Laid-Open No. 1-141872, "MgO-C brick using a phenol resin as a binder, SiO ₂ is added to ˜50% and a method of adding a glass containing SiO ₂ having an alkali content of 10% by weight or less ”. In this example, the added inorganic material is "glass", which is different from the binder used when manufacturing the refractory, and the purpose of its use is to prevent the magcarbon reaction. It serves as an auxiliary additive when the binder is the main binder. Therefore, it is completely different from the purpose of use such as "the effect of preventing the generation of odorous gas, the effect of preventing the oxidation of carbon, the effect of improving the spalling resistance" which is the feature of the present invention, and suggests the effect of the inorganic binder in the present invention. Not something to do. Moreover, the present invention is different from the present invention on the premise that "no organic binder such as a phenol resin is mixed" in its constitution.

Similarly, as an example of using an inorganic additive in a carbon-containing brick, "Application of magnesium phosphates to magnesia refractory material and carbon material" is disclosed in JP-A-5-24910. Has been done. Also in this example, the binder used in the production of the refractory is a conventional phenol resin, and its purpose is to prevent carbon oxidation. Therefore, it is completely different from the purpose of use such as "preventing generation of odorous gas or smoke" which is a feature of the present invention.

Further, Japanese Patent Laid-Open No. 43354/1993 discloses that a graphite-containing brick (graphite-containing brick used for various nozzles and tundish in continuous casting equipment) is coated with an antioxidant containing an inorganic component. , A method for preventing the oxidation of the brick. " In this example, an inorganic substance is used for an antioxidant coating, and its use is fundamentally different from the present invention using an inorganic binder as a binder for carbon-containing bricks, and is a feature of the present invention. It does not suggest the action and effect such as "the effect of preventing the generation of odorous gas and the improvement of spalling resistance".

As described above in detail, the application of the inorganic binder or the inorganic substance to the refractory bricks up to now is different from the purpose of using the inorganic binder in the present invention, and is also exhibited in the present invention. There is no content that suggests the above-mentioned effects of the inorganic binder.

On the other hand, in the case of amorphous refractories, the application of inorganic binders to refractories has been conventionally practiced, and inorganic binders such as silicates, phosphates and cements are generally used. For example, JP-A-52-154818, JP-A-3-33068, JP-A-10-118762 and the like disclose examples of the use of sodium silicate in an amorphous refractory containing carbon. The purpose of using the inorganic binder in these examples is to improve the volume stability and adhesiveness at high temperature (JP-A-52-154818), and to secure the shape retention by eliminating the fluidity of the kneaded material ( JP-A-3-33068,
JP-A-10-118762). Therefore, it is different from the purpose of use such as "the effect of preventing the generation of odorous gas, the effect of preventing the oxidation of carbon, and the effect of improving the spalling resistance" which is a feature of the present invention, and particularly when applied to a carbon-containing unfired brick. It does not suggest the effect of the inorganic binder exerted.

Further, in the case of amorphous refractories, research is being conducted to reduce the amount of the inorganic binder to be used as much as possible from the idea that the inorganic binder "reduces the corrosion resistance" because it forms a substance having a low melting point. However, the present inventors, without being bound by this conventional idea, as a result of repeating the experiment by free thinking, in the carbon-containing unfired brick according to the present invention, even if an inorganic binder is applied, the corrosion resistance It was found that no decrease occurred, and the present invention was completed.

In the carbon-containing brick, one of the reasons why the corrosion resistance is not deteriorated is considered to be the essential difference in the refractory structure due to the difference in molding method. That is, the amorphous refractory has a high porosity (15% or more even if it is low) because it is molded under the condition that the pressure is very small, such as flow utilizing gravity or filling by spraying force. Therefore, intrusion of slag is likely to occur, the structure deteriorates, and it is difficult to obtain sufficient corrosion resistance. If an inorganic binder is present under such conditions, the low-melting point substance generated at high temperature will accelerate the deterioration of the refractory structure by promoting the invasion of slag, and it is presumed that the corrosion resistance is further reduced. To be done.

On the other hand, since the carbon-containing brick is press-molded under high pressure, the porosity becomes about several percent and a dense structure is formed. Therefore, deterioration of the structure due to slag intrusion is unlikely to occur and high corrosion resistance is exhibited. In this case, since the structure of the dense brick is maintained, the deterioration of the structure is less likely to be promoted even if the inorganic binder is present, and the desired action effect such as “the effect of suppressing the oxidation of carbon and the creep deformability” is generated due to the low melting point substance generated. Is considered to be obtained. That is, the carbon-containing unfired brick according to the present invention has a fine structure formed by high-pressure molding, and therefore, when an appropriate amount of an inorganic binder is used, deterioration of corrosion resistance does not occur, and it is recognized by a conventional amorphous technique. It was confirmed that an action effect different from the existing phenomenon was exhibited.

The embodiments of the present invention will be described below. The inorganic binder that can be used in the present invention is not particularly limited as long as it is in accordance with the above-mentioned gist of the present invention, but for example, "forming a silicate bond." Substance (preferably sodium silicate, potassium silicate, lithium silicate, ethyl silicate, colloidal silica, etc.), "substance forming a phosphoric acid bond (preferably sodium phosphate, aluminum phosphate, etc.)", "cement (alumina cement,
(Magnesia cement and the like are preferable) ". These can be used alone or in combination.

In the present invention, the addition amount of the inorganic binder is not particularly limited, but is preferably in the range of 0.1 to 8% by weight. If the amount of the inorganic binder added is less than 0.1% by weight, the above-mentioned effects cannot be sufficiently obtained, and the strength of the brick becomes low, which is not preferable. On the other hand, if the amount of the inorganic binder added exceeds 8% by weight, the amount of the low melting point substance produced at high temperature becomes too large, and the corrosion resistance of the brick deteriorates, which is not preferable.

Next, regarding the raw materials usable in the present invention,
This will be specifically described. Examples of the refractory raw material that can be used in the present invention include oxides such as magnesia, alumina, spinel, calcia, dolomite, silica, chromia, zirconia, and titania, their complex oxides, coexisting raw materials thereof, or electromelting. Generally used refractory raw materials such as raw materials, silicon carbide, silicon nitride, silicon oxynitride, boron nitride, boron carbide, zirconium boride and the like can be arbitrarily used, and all are included in the present invention. .

The carbonaceous raw material that can be used in the present invention is not particularly limited, but commonly used raw materials include natural graphite such as scaly graphite and earth graphite, artificial graphite such as coke, electrode scrap, and carbon. Examples thereof include fibers and pyrolytic carbon. The amount of the carbonaceous raw material used is not particularly limited, but is preferably in the range of 1 to 40% by weight. If it is less than 1% by weight, the spalling resistance is lowered and the effect of preventing slag infiltration is insufficient, which is not preferable. On the other hand, if it exceeds 40% by weight, the structure deterioration due to oxidative damage and the wear damage are likely to occur, and the thermal conductivity of the brick increases, resulting in a decrease in the temperature of the molten metal, which is not preferable.

In the present invention, the refractory raw material and the carbonaceous raw material are used, but a metal may be added if necessary for the purpose of imparting strength to the brick. Examples of the metal that can be used in the present invention include silicon, aluminum, magnesium, titanium, chromium, zirconium and the like, or alloys and mixtures thereof. The amount of addition is preferably 0.1 to 5% by weight within a range in which the expected effect is sufficiently obtained and the strength of the brick does not become excessively high.

[0036]

Next, examples of the present invention will be given together with comparative examples.
The present invention will be specifically described. Table 1 shows binders (Binders A to G) used in the following Examples and Comparative Examples.

[0037]

[Table 1]

Example 1 A raw material composed of 70% by weight of fused alumina, 15% by weight of fused magnesia, and 15% by weight of scaly graphite was externally coated with 2% by weight of aluminum and 2% by weight of silicon.
After adding 1% by weight and 3% by weight of Binder A and kneading, press molding into a parallel shape (230 × 114 × 65 mm),
It was dried at 50 ° C. for 12 hours to obtain a test sample (Example 1).

Example 2 A raw material composed of 80% by weight of fused alumina, 5% by weight of silicon carbide, and 15% by weight of scaly graphite was added.
Aluminum 2% by weight, silicon 1% by weight
After adding 3% by weight of binder A and 1% by weight of binder D and kneading, press-molding into a parallel shape (230 × 114 × 65 mm) and drying at 250 ° C. for 12 hours.
(Example 2).

Example 3 To a raw material composed of 70% by weight of fused alumina, 15% by weight of silicon carbide and 15% by weight of scaly graphite, 2% by weight of aluminum and 1% by weight of silicon were added by external coating, and binder A was added. 3% by weight and binder F
After adding 1% by weight and kneading, the parallel shape (230 x 114 x 65 m
m) was press-molded and dried at 250 ° C. for 12 hours to obtain a test sample (Example 3).

Example 4 2% by weight of aluminum and 1% by weight of silicon were externally added to a raw material composed of 85% by weight of electrofused spinel and 15% by weight of scaly graphite, and 3% by weight of binder B and 3% by weight of binder were added. After adding 0.5% by weight of F and kneading, press-molding into a parallel shape (230 × 114 × 65 mm),
It was dried at 250 ° C. for 12 hours to obtain a test sample (Example 4).

[Example 5] 95% by weight of fused magnesia,
After adding 2% by weight of aluminum and 1% by weight of silicon to the raw material consisting of 5% by weight of carbon black, kneading by adding 3% by weight of binder B and 0.5% by weight of binder E, and then kneading It was pressed into a shape (230 × 114 × 65 mm) and dried at 250 ° C. for 12 hours to obtain a test sample (Example 5).

[Example 6] 85% by weight of fused magnesia,
2% by weight of aluminum and 1% by weight of silicon were added to a raw material composed of 15% by weight of scaly graphite, 3% by weight of binder A was added, and the mixture was kneaded to obtain a parallel shape (230 × 114).
× 65 mm) was press-molded and dried at 250 ° C. for 12 hours to obtain a test sample (Example 6).

[Example 7] 80% by weight of fused magnesia,
2% by weight of aluminum and 1% by weight of silicon are externally added to a raw material composed of 20% by weight of scaly graphite, 3% by weight of binder A and 0.5% by weight of binder C are added, and the mixture is kneaded. It was pressed into a shape (230 × 114 × 65 mm) and dried at 250 ° C. for 12 hours to obtain a test sample (Example 7).

[Comparative Example 1] 85% by weight of fused magnesia,
After adding 2% by weight of aluminum and 1% by weight of silicon to the raw material consisting of 15% by weight of scaly graphite and 3% by weight of binder G, and kneading, a parallel shape (230 × 114
× 65 mm) was press-molded and dried at 250 ° C. for 12 hours to obtain a test sample (Comparative Example 1).

[Comparative Example 2] 80% by weight of fused magnesia,
3% by weight of aluminum and 1% by weight of silicon were externally added to a raw material composed of 20% by weight of scaly graphite, and 3% by weight of a binder G was added and kneaded to obtain a parallel shape (230 × 114).
× 65 mm) was press-molded and dried at 250 ° C. for 12 hours to obtain a test sample (Comparative Example 2).

[Comparative Example 3] A raw material consisting of 87% by weight of fused alumina, 10% by weight of fused magnesia, and 3% by weight of pitch was kneaded by externally adding 5% by weight of binder F and 1% by weight of binder A. After that, cast into various test shapes,
After curing, it was dried at 250 ° C. for 12 hours to obtain a test sample (Comparative Example 3).

COMPARATIVE EXAMPLE 4 5% by weight of binder F and 1% by weight of binder B were externally added to a raw material consisting of 80% by weight of electrofused spinel, 15% by weight of silicon carbide and 5% by weight of pitch, and kneaded. Then, it was cast into various test shapes, cured, and dried at 250 ° C. for 12 hours to obtain a test sample (Comparative Example 4).

[Comparative Example 5] 80% by weight of fused magnesia,
After mixing 5% by weight of binder E and 0.5% by weight of binder B by external coating to a raw material consisting of 15% by weight of fused alumina and 5% by weight of pitch, the mixture was cast into various test shapes and cured. Samples dried at 250 ° C for 12 hours
(Comparative Example 5).

The bulk specific gravity and porosity of the above 12 samples (Examples 1 to 7 and Comparative Examples 1 to 5) were measured, and the results are shown in Table 2 (Examples) and Table 3 (Comparative Examples). Indicated. Further, the following evaluation test was performed for the degree of odor and smoke generated when exposed to heat. The results are also shown in Table 2 (Examples) and Table 3 (Comparative Examples). (Odor and Smoke Evaluation Test) In the odor and smoke evaluation test, each sample was inserted into an electric furnace maintained at 800 ° C., and the odor generated at that time was smelled by three test subjects. The state of smoke generation was observed and evaluated.

Further, 12 samples (Examples 1 to 7 and Comparative Examples 1 to 5) were subjected to the following "Evaluation tests for corrosion resistance, oxidation resistance and spalling resistance". The results are also shown in Table 2 (Examples) and Table 3 (Comparative Examples).

(Evaluation Test of Corrosion Resistance) The corrosion resistance test was carried out at 1650 ° C. for 5 hours using a rotary drum heated by oxygen propane, and “CaO = 50% by weight, SiO ₂
= 30 wt%, Al ₂ O ₃ = 10 wt%, MgO = 10 wt% ”synthetic slag was added. The corrosion resistance was evaluated by measuring the erosion amount from the cut surface of the sample after the erosion test. (Oxidation resistance evaluation test) Oxidation resistance was measured by using a hearth rotary electric furnace to elevate the temperature of the test sample from room temperature to 1400 ° C and hold it in the atmosphere for 3 hours. And the oxide layer thickness was measured and evaluated. (Evaluation test of spalling resistance) The spalling resistance is
It was judged based on the results of the spalling test by the hot metal immersion / water cooling method. The "hot metal immersion / water cooling method" is a method in which 10 kg of pig iron is melted in a high-frequency induction furnace and held at 1650 ° C as a heat source, and half of the prismatic sample is immersed in hot metal for 60 seconds. After holding it, take it out from the hot metal and put it in water 15
It is a method of evaluating spalling resistance from the state of crack generation by observing the cut surface structure of the obtained sample after holding for a second and then allowing to cool in the atmosphere.

[0053]

[Table 2]

[0054]

[Table 3]

The following can be seen from Tables 2 and 3. As a result of evaluation of odor and smoke, in the conventional carbon-containing unfired bricks (Comparative Examples 1 and 2) using a phenol resin (binder G), a strong irritating odor and a large amount of black smoke were generated. Further, in Comparative Examples 3 to 5 in which "pitch" is blended, smoke is observed, whereas inorganic binders (binders A to F) such as silicate, phosphate, and cement are applied and no pitch is blended. Carbon-containing unfired brick of the present invention
In Examples 1 to 7, no odor was sensed and no smoke was emitted.

Examples 1 to 7 of the present invention have porosities of about 6% after drying, although there are differences depending on the type of aggregate, but they are about 8.5% after reduction baking at 1000 ° C., Since the increase in porosity is about 3%, which is very small,
It can be seen that a dense structure can be maintained even after firing at 1000 ° C. Further, the porosity after firing at 1500 ° C. was about 10%, and it was confirmed that the porosity equivalent to that of the conventional graphite-containing unfired bricks shown in Comparative Examples 1 and 2, that is, the denseness of the structure was maintained.

As a result of evaluation of corrosion resistance, Example 4 of the present invention
Nos. 7 to 7 exhibited corrosion resistance equivalent to that of the conventional graphite-containing unfired bricks shown in Comparative Examples 1 and 2. In addition, Example 1 of the present invention ~
No. 7 showed very good corrosion resistance as compared with Comparative Examples 3-5.

As a result of evaluating the oxidation resistance, Examples 1 to 7 of the present invention obtained very good results as compared with Comparative Examples 1 to 5. As for the spalling resistance, Examples 1 to 7 were equal to or better than Comparative Examples 1 to 5, and good evaluation results were obtained.

As described above, since the carbon-containing unfired brick according to the present invention does not have the "generation of harmful organic gas when heated" which is a problem in the prior art, generation of odor and smoke is completely eliminated. It is apparent that the corrosion resistance is prevented, the oxidation resistance and the spalling resistance are both excellent, and the corrosion resistance is not deteriorated.

[0060]

The carbon-containing unfired brick according to the present invention is
As described above in detail, "in a raw material mixture containing a refractory raw material and a carbonaceous raw material, the raw material mixture contains an inorganic binder, and does not generate odor and / or smoke during the heating process" , By this, working environment,
From the viewpoint of improving the local environment and the global environment, there is no generation of odor and smoke which are problems when heated, and the oxidation damage, which has been a problem in the past, is reduced and the spalling resistance is excellent. It is possible to provide an environment-friendly high durability carbon-containing unfired brick.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F27D 1/00 F27D 1/00 N (72) Inventor Kazuhiro Inoue 9-1 Kitakita 4-chome, Chiyoda-ku, Tokyo No. of goods Kawashiro Brick Co., Ltd. (72) Inventor Masahiro Yoshida No. 4-7, Kudankita 4-chome, Chiyoda-ku, Tokyo No. 4G033 AA02 AA03 AA15 AB02 AB03 AB04 AB05 AB09 AB10 AB24 BA01 4K051 AA06 AB03 AB05 BE01 BE03

Claims (8)

[Claims] 1. A raw material blend containing a refractory raw material and a carbonaceous raw material, wherein the raw material blend contains an inorganic binder and does not generate odor and / or smoke during the heating process. Contains unfired brick. 2. The carbon-containing unfired brick according to claim 1, wherein the inorganic binder contains a substance forming a silicate bond and / or a substance forming a phosphoric acid bond. 3. The material forming the silicate bond is sodium silicate, potassium silicate, lithium silicate,
The carbon-containing unfired brick according to claim 2, which is one or more selected from ethyl silicate and colloidal silica. 4. The carbon-containing unfired brick according to claim 2, wherein the substance forming the phosphate bond is sodium phosphate or aluminum phosphate. 5. The carbon-containing unfired brick according to claim 1 or 2, wherein the inorganic binder contains cement. 6. The cement according to claim 5, which is an alumina cement or a magnesia cement.
The carbon-containing unfired brick described in. 7. The carbon-containing unfired brick according to claim 1, wherein the raw material mixture contains a metal for imparting strength. 8. The metal is silicon, aluminum,
The carbon-containing unfired brick according to claim 7, which is one or more selected from magnesium, titanium, chromium and zirconium, or an alloy thereof.