JPS59217672A - Manufacture of carbon refractories for blast furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing carbon refractories for blast furnaces, and in particular, to produce molded products that are dense, have high compressive strength, have low air permeability, are excellent in hot metal corrosion resistance, and have high thermal conductivity. It's something you get.

Carbon refractories for blast furnaces are carbonaceous aggregates such as graphite mixed with coal tar pitch and phenolic resin N'4 (7) binder.
After blending about ~20%, it is formed into a predetermined shape and fired.The conventional one is anthracite, which has the least carburization property compared to the corrosivity of molten pig iron at 1150-1600℃. It is made by adding a small amount of i graphite to it. Although the aggregate itself has excellent hot metal corrosion resistance, the air permeability of the molded product is high, and the thermal conductivity is low at 10 to 15 kca LAnh℃. The molten pig iron has low corrosive properties, and the lower the thermal conductivity, the higher the temperature of the working surface increases and the wear and tear due to heat increases, resulting in the disadvantage of shortening the service life of the blast furnace. . Also,
As a means to operate a blast furnace economically, cooling water is passed through the furnace walls. During high-output ratio operation, the amount of cooling water is increased to cool the working surfaces and protect the furnace body, and during low-output ratio operation, the furnace body is protected. It is desirable to strengthen heat retention by reducing the amount of cooling water. In other words, in order to carry out such operations, it is essential that the thermal conductivity of carbon refractories be high. In view of the above points, conventional methods have been used to increase the thermal conductivity of carbon refractories. method was tried. By increasing the thermal conductivity of the carbon refractory, cooling in the direction of the side wall at the bottom of the blast furnace is strengthened to a greater extent, thereby transferring the isothermal refractory to the inside of the furnace.

It is intended to form a permanent adhesive layer on the working surface.

It is known that distressed graphite increases the thermal conductivity of carbon refractories, and hexagonal natural graphite, such as JISM
When 860 is kneaded with the 1960-related material graphite and an appropriate caking agent (dextrin, lignin, phenol resin, acrylic resin, furan resin, tar, pitch, etc.), it is molded and fired at 500℃ or higher. Thermal conductivity is 10
It is known that one having a temperature of 0 to 150 kcJ/rnh°C can be obtained. However, with this method, fzE-shaped products can be obtained that are relatively homogeneous and free of laminations at about the size of a regular brick (65 x 114 x 230 mm). If a large-sized molded product is used for the bottom side wall, internal structure defects and anisotropy will become abnormally large, resulting in a product with low strength and problems such as cracking and lamination.

In an attempt to solve this problem, attempts have been made to develop carbon refractories that utilize the characteristics of scale-like graphite and have a strong structure.

For example, fine graphite is made into a fine powder (0.074 mm or less, including 50% of 4411 m+ or less), mixed with tar, the resulting powder is placed in a rubber mold, and isostatically isostatically molded at room temperature. It is a method for obtaining refractories (Japanese Patent Application Laid-open No. 1983-
No. 23410).

In this method, if the molded product becomes even slightly large, the rubber mold will separate from the bottom body during the pressure reduction process during molding.
A method of manufacturing carbon refractories with high thermal conductivity using O2, which is prone to cracking in molded bodies due to poor degassing in the low pressure range of 1 kg/-, and has a significantly poor molding yield, has also been attempted (Unexamined Japanese Patent Publication No. (Sho 57-67011).

In this case, lamination cracks due to springback that occur during molding can be prevented, but in the case of large molded products, 2 min. Therefore, to prevent this, the firing speed should be /J
Even if you take measures such as reducing the percentage, it is not possible to completely erase the built-in data. Ori also uses CE-2 grade flaky graphite (flake size 3 to 0.3 m), which is equivalent to JIS.
It was also attempted to make carbon refractories by replenishing refractory raw materials to caking organic powder (phenolic resin powder) using m) and utilizing the card house alignment phenomenon by high-pressure molding at 800 kg/an2. Kaisho 55-8546
No. 1) 0 With this method, when the compact becomes larger, the bulk density of the powder before filling is extremely small (0.3 g/cm3), but on the other hand, the bulk density after high-pressure molding becomes 2.0 g/am3, which is 7 times as large. It must be compressed and the degassing must be done uniformly.
・The amount of springback after demolding becomes large and lamination cannot be prevented.

In all of the above methods, when molding a small tenuto piece, a molded product with high thermal conductivity suitable for the purpose can be obtained, but when trying to mold a large molded product suitable for practical use, lamination etc. It happens.

The present inventors studied the problems caused by the above-described conventional methods. As a result, the cause of the above problems is mainly due to the organic binder, the method of kneading the mixture, and the accompanying molding method. First, graphite or other aggregate is impregnated with an organic solvent such as ethylene glycol, and then the Add phenol resin to the mixture and use a twenty-one-day blender to convert it to lO~
It was discovered that a large molded product with no lamination etc. could be obtained by kneading while applying a pressure of 100 g/am2, and then a molding pressure of 100 to 250 kg Am''. It has been discovered that by setting it to 250 ky'cm2 or less, it is possible to add p-coke type graphite, thereby obtaining a molded product with high strength and low air permeability, and based on this, the present invention is intended to be provided. It is.

The present invention will be specifically explained below. As described above, in the present invention, aggregate is impregnated with an organic solvent, phenol resin is added thereto, and the mixture is kneaded and molded using a two-der blender. It is possible to obtain molded products with extremely low thermal conductivity and high thermal conductivity.
As an example, a material whose main component is scaly graphite is shown. Therefore, the aggregate is a mixture of scale graphite, anthracite, coke thread artificial graphite, carbide powder, metal powder, etc. Scale graphite is a hexagonal flaky graphite with an a-axis crystallite size of II" LalOooA or larger, and the flake size is 3 to 0.3 m.
For example, anthracite-based scaly graphite graphitized at 00° C. or higher, chirashi graphite produced by precipitation of metallic molten carbon, earthy graphite roasted at 1500° C. or higher, naturally produced scaly graphite, etc. This scaly graphite itself has an extremely large natural filling capacity, reaching 90% of its theoretical density (1,8-2, Og/cm3) under a restraining load of 200 kg/c♂.
It has the property of springing back when released. Molded graphite scales using only scaly graphite as aggregate have extremely good thermal conductivity, but the graphite tends to slip on each other during molding, so lamination is likely to occur, and the porosity is high, resulting in resistance to Since the tension and counter pressure are low, it cannot be used as a blast furnace material. Coke-based graphite,
Anthracite, carbide powder, and metal powder remove the defects in graphite scales, and coke-based graphite fills the voids in the skeleton of graphite scales and is interposed as a dense layer, increasing the air permeability of the molded product. It is used as a structural material and increases the strength of molded products.
Metallurgical coke graphitized at a temperature of 2000 to 2300°C, coke pre-impregnated with an aromatic carbonaceous organic compound with a carbonization rate of 30% or more and then semi-graphitized at the same temperature, or an organic silicon compound (e.g. After impregnating it with polycarbosilane, etc., it is graphitized at the above temperature.
0, lrrIm coke, etc. may also be used. Anthracite similarly lowers the air permeability of the molded product, increases its strength, and particularly improves its carburization resistance. Carbide reduces the lubricity and j'awn of scale graphite, makes the molded product more dense, and prevents lamination.9
The metal powder (silicon, aluminum) is a carbon sintering agent and combines with the carbon of graphite to produce β-8C, etc.
This increases the mechanical strength of the molded product and reduces the air permeability.

As mentioned above, the aggregate made by mixing scale graphite with coke-based graphite, etc. is put into a kneader blender, and then an organic solvent such as ethylene glycol is added and stirred to coat the surface of the aggregate with the organic solvent and crack it. Impregnate the gaps etc. with this. The organic solvent then exerts a force of 1 on the aggregate.
The material is not particularly limited as long as it dissolves the phenolic resin produced and coats the aggregate evenly and improves the adhesion with the aggregate, and has this function2.・The function must last at least until the material is pressed and molded.9 Also, the viscosity of the melted phenolic resin must be adjusted to an appropriate value in order to obtain a molded product with low porosity. I also need it. From this point of view, glycols such as ethylene glycol are suitable as organic solvents.Next, finely divided phenol resin and...
Or add a high viscosity phenolic resin solution i, to ~10
Knead for several minutes to several tens of minutes while applying a pressure of 0 g/Cm2.

By the way, when ethylene glycol is used as the organic solvent and the amount added is 0.5 to 0.1 times that of the phenol resin, it is desirable to heat the material to about 70 to 90°C during kneading. In other words, by doing this, the phenolic resin will have a viscosity suitable for molding large molded products, and the aggregate will have a structure with a card house structure.
This is because the strength of the molded product increases as the air permeability of the molded product decreases. In this case, it is preferable to heat the aggregate to about 100 to 105° C. at the stage of impregnating the aggregate with the organic solvent, then transfer the mixture to another kneader blender, add the phenol resin thereto, and knead it. In this way, the mixture is not heated from the outside during kneading, so all the mixtures are at the same temperature, and there is no concern that the phenol resin will harden locally, and a homogeneous molded product can be obtained. .

Similarly, one method is to dissolve a portion of the phenolic resin in an organic solvent.

In this way, when impregnating the aggregate with an organic solvent,
Since the aggregate is reliably coated with the phenol resin, the effect of the phenol resin as a binder is more reliably exhibited. Finally, the above-mentioned kneaded material is filled into a mold, compression molded at a pressure of 250 kg/crn2 or less, and then dried and fired according to a conventional method.

Here, the present invention is characterized in that it can be molded at a pressure of 250 kg/am2 or less, and since graphite, especially coke-based graphite, is hardly crushed at this pressure, it is not possible to add graphite as aggregate. This makes it possible to further increase the strength of the molded product and reduce its porosity.

Example 1 200kg/cm2 CD compression resulted in a compacted powder density of 2+
Og/am" or more, and the flake size is 3 to 0.3 mm
50 parts of natural flaky graphite with a particle size of 4.5 to 0, lrnm s
25 parts of Coconu-based artificial graphite with a true specific gravity of 2.13 or more, a lattice constant Co of 6.85λ or less, and a particle size of 0.074mTh
15 parts of the following silicon carbide fine particles and 10 parts of metallic silicon were put into a kneader blender with a capacity of 300 fl, and 2.5 parts of ethylene glycol was added thereto, and the aggregate was kneaded for 10 minutes while heating to 100 ° C. The aggregate was impregnated with ethylene glycol, then transferred to another kneader blender, 18 parts of powdered phenol resin was added thereto, and the mixture was kneaded for 30 minutes while applying a pressure of 50 g/am2. Subsequently, the inner volume was discharged, and the above-mentioned kneaded material was filled into a 3 m3 mold, and a block was formed by pressurizing the mixture at a pressure of 200 kg/cm2 for 5 minutes. The obtained molded body was dried at 250°C in a nitriding atmosphere while preventing low-temperature oxidation of the surface, and then annealed to 1300°C in a reducing atmosphere. Example 2 Same as Example 1. 50 parts of natural scaly graphite with a particle size of 4.5 to 0
．． 25 parts of anthracite of 1rrrn and particle size of 0.07
15 parts of silicon carbide fine particles of 4 mm or less, and 10 parts of metallic silicon
2.4 parts of ethylene glycol and 1 part of ethyl alcohol were added to a kneader blender with a capacity of 300 i.
A solution in which 3 parts of phenolic resin was dissolved was added to a mixed solution of 0 parts, and the mixture was kneaded for 10 minutes while heating to 100°C to incorporate the solution into the aggregate and evaporate the ethyl alcohol in the solution. Transfer this to another kneader blender and add resol type phenolic resin 158k to it.
71D D. A pressure of 50 g/cm2 was applied to the mixture and kneaded for 30 minutes. Next, add the kneaded material to an internal volume of 0+'
The mixture was filled into a 3rn3 mold and pressed at a pressure of 200 kg/crn2 for 5 minutes to form a block. The obtained molded body was heated in a nitrogen atmosphere to prevent low-temperature oxidation of the surface\2
After drying at 50°C, it was fired to 1300°C in a reducing atmosphere. As shown in Table 1, the obtained molded product had a thermal conductivity of 60 kcal-Ah'C or more, an air permeability of 400 millidarcy or less, and a bending strength of 120 kg/am2.
Based on the above results, it was suitable as a high-temperature furnace material with almost no pressurized hot metal permeability and excellent carburization resistance.The test method was as follows:
For the pressurized penetration test method, a 5-square sample I is vacuum degassed, immersed in hot metal 2, connected and pressurized with gas 4 in a container 3 to a pressure of 5 kg/cm2, and after the test, sample I is Removal and cutting 1 After cutting and microscopic observation, the amount of hot metal infiltration was estimated from the area ratio and expressed as an index. Sample (0% 15
7 is constructed and held in contact with hot metal 8 at 1550°C.

After the test, the amount of erosion loss was actually measured from the surface, and the erosion loss volume index was determined.

As detailed above in Table 1, in the present invention, aggregate is first impregnated with an organic solvent, then phenol resin is added thereto, kneaded under pressure, and then molded. By doing so, -p low pressure release was made possible. Therefore, it is possible to add coke-based artificial graphite, and a product with high thermal conductivity, high strength, and almost no air permeability can be obtained.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the pressure penetration test method, Figure 2 (a) is an explanatory diagram showing the hot metal resistance test method by single-sided cooling, and Figure 2 (b) is a plan view of the same. 381 Procedural Amendment (Voluntary) May 15, 1980 Director General of the Patent Office Kazuo Orisugi 1 1 Indication 1981 Special Planner No. 91355 2 Title of Invention Process for producing carbon refractories for blast furnaces 3 Relationship with the case of the person making the amendment Patent applicant 4, agent address 7, 2nd floor, New Ximending Building, 2-7, Ximending, Shizuoka City;
The subject of the amendment is the full text of the KLL document 8, the content of the amendment is as per the separate label, the details are 1, title of the invention method for producing carbon refractories for blast furnaces 2, scope of claims organic solvent 3 in 100 parts of aggregate for carbon refractories. It is characterized by adding ~13 parts and mixing, coating the surface of the aggregate particles with this, then adding 10 to 40 parts of a powdered binder and mulching, followed by molding, drying, and firing. Manufacturing method for carbon refractories for blast furnaces. A method C for producing carbon refractories for blast furnaces according to claim 1, wherein the shoulder bonding material is a hardening phenol resin.The thermosetting phenolic resin is 50 parts of a novolac type plasticizing phenol resin and a benzylic ether type hardening resin. Method C for producing a carbon refractory for blast furnaces made from 3 to 50 parts of a curable phenolic resin.
Claim 1, 2, or 3, characterized in that the solvent is glycol. Method for producing carbon refractories for blast furnaces according to claim 1, paragraph 2, or 3. Rick ether type thermosetting phenolic resin 3~
Fenok MI l1iW I O (
1 part of the carbon refractory for blast furnaces according to claim 1, claim 2, or claim 3, wherein 1 part of glycol is dissolved in 10 to 35 parts of glycol. The aggregate was compressed at 200 kg/an to a compact density of 2. The flake size is Og/crn3 or more or 3 to 0.3
Field scale graphite 40-60s1 particle size 4.5-0.1rri
15 to 30 parts of Coconu-based artificial graphite of m, grain i0.074
10 to 20 parts of carbide below mtn and 5 parts of metal powder
Claim 1, characterized in that it consists of ~15 parts.
Term, 2nd term, 3rd ode, φth term, or Yan! Koukiki's method for manufacturing carbon refractories for blast furnaces〇Tuna-like graphite is hexagonal flaky graphite with an a-axis crystallite size or La1000A or more, and is anthracite fiber graphite that has been graphitized at temperatures above 2700℃.
The method for producing carbon refractories for blast furnaces according to claim 6, characterized in that the graphite is quiche graphite produced by precipitation of all-pole molten carbon, scale graphite made from natural sheaths, or green graphite roasted at 1500°C or higher. . Coke-based artificial graphite has a particle crushing strength of 200 kg/an2
Artificial graphite for electrolytic plates and electrodes having the above, 2000-23
Metallurgical coke semi-graphitized at a temperature of 00℃, or petroleum coke, pitch, coke, metallurgical coke with a carbonization rate of 3
After impregnating with 0% or more of an aromatic carbonaceous organic compound or an organic silicon compound such as polycarbosilane, 200()-
The coke is semi-graphitized at a temperature of 2300° C.'f: A method for producing carbon refractories for blast furnaces according to claim 6. What is organic solvent coated aggregate and organic binder?
8. The method for producing carbon refractories for blast furnaces according to claim 7, characterized in that W, NuT is produced under a pressure of ~100 g/cm2. 3. Detailed Description of the Invention The present invention relates to a method for producing carbon refractories for blast furnaces, and provides molded products that are particularly dense, have high compressive strength, have low air permeability, are excellent in hot metal corrosion resistance, and have high thermal conductivity. Carbon refractories for blast furnaces are carbon aggregates such as graphite and binders such as coal tar pitch and phenolic resin at 1υ~20%.
After blending to a certain degree, it is molded into a predetermined shape and fired, and the conventional one is mainly composed of anthracite, which has the least carburization property against the corrosive properties of hot metal at 1150 to 1600°C.
It is made by adding a small amount of graphite to this.
Although the aggregate itself has poor corrosion resistance against hot metal, the molded product has a high air permeability and a thermal conductivity of 10 to 15 kca.
As low as 4/rnh°C. The higher the ventilation rate, the more
Since the permeability is high, the corrosion resistance of the hot metal is low, and the similar the thermal conductivity, the higher the temperature of the working surface and the greater the wear and tear9, which ultimately reduces the service life of the blast furnace. There are disadvantages to shortening. In addition, as a means to operate a blast furnace economically, cooling water is passed through the furnace wall, and during high iron production, the amount of cooling water is increased to cool the furnace body and reduce the It is desirable to reduce the amount of cooling water and strengthen heat retention during the extraction process. That is, in order to carry out such operations, it is essential that the carbon refractory has high thermal conductivity. In view of the above points, FPNF of carbon refractories has been
E-conductivity Ti: Attempts have been made to increase the conductivity. By increasing the thermal conductivity of carbon refractories, cooling in the direction of the side walls at the bottom of the blast furnace is greatly strengthened, thereby moving the isotherm to the inside of the furnace and forming a permanent foam layer on the working surface. It is an attempt to do so. ' It is known that scaly graphite increases the thermal conductivity of carbon refractories, and hexagonal natural graphite, fj+, has a suitable caking side ( dextrin, lignin,
Phenol Tsukugetsuji, acrylic Ryugetsuji, furan Jugetsuji, tar, pitch, etc.) are added and kneaded, then molded.
Thermal conductivity is 100~150kc when fired at 00℃ or higher
It is known that the temperature of aj/rrh°C can be obtained. However, this method is not suitable for molded products or ordinary brick size (65 x 1
14 x 230 mm) is relatively uniform and has no lamination, and is suitable for use as a refractory material for sealing inside industrial furnaces, especially for large molded products used for the walls of blast furnace bottoms. If this is attempted, problems such as internal structure defects and anisotropy become abnormally large, resulting in ibis red beans, cracks, and lamination. In order to solve this problem, there have been a number of attempts to develop carbon refractories that have a strong structure that takes advantage of the characteristics of scaly graphite. For example, fine powder of scaly graphite (O1 containing 44 or less or 50%
074 rrm or less), blend tar into this, put the obtained powder into a rubber mold, and perform isostatic pressure isostatic molding at room temperature.
This is a method for obtaining a carbon fiber refractory (Japanese Unexamined Patent Publication No. 50-23
No. 410) 0 With this method, if the molded product becomes even slightly large, the rubber mold will separate from the molded product during the pressure reduction process during molding.
In the low pressure area of 1 cg/crrI2, molded products tend to crack due to poor deaeration, resulting in a markedly poor molding yield. In addition, by adding cemented carbide pitch powder to scaly graphite and suppressing it by adding a heptadheteral modified phenol resin liquid, carbon with high thermal conductivity can be produced by utilizing the rapid increase in viscosity during the molding process. A method for manufacturing refractories was also tried out (%Kokai No. 57-67011). In this case, lamination cracks due to springback that occur during molding can be prevented, but in the case of large-formed products, the In the temperature range of ~500℃, lamination is likely to occur due to abnormal volumetric expansion and contraction of the pitch.Therefore, even if measures are taken to prevent this, such as reducing the firing speed, the built-in lamination 2 cannot be completely eliminated. Alternatively, CE-2 grade scale graphite (flake size 3 to 0.3 mm) equivalent to JIS Tr:
Attempts have also been made to make carbon refractories by applying refractory raw materials to caking organic p powder (phenol soybean powder) and utilizing the card house alignment phenomenon through high-pressure molding at 800 kg/cm2. (No. 85461, 1973). In this method, when the compact becomes large, the bulk density of the powder before filling is extremely small (0.3 g/c [T+3), but on the other hand, the bulk density after high-pressure molding becomes 0.0 g/cm, so it can be compressed by 7 times. Otherwise, the degassing will not be done evenly.
Due to the amount of springback after demolding, the occurrence of thick lice cannot be prevented. All of the above methods produce molded products that are suitable for the purpose and have high conductivity when molding small test pieces, but when trying to mold large molded products that are suitable for practical use. Lamination, etc. will occur. The reason why such problems occur in the conventional method is due to an inappropriate method of mixing the butt joint material and the bone phase. In other words, the organic binder not only binds the aggregate particles together, but also carbonizes itself to form a part of the product. It is essential to have uniform placement, no voids, strong contact force with the aggregate particles, and similar porosity after carbonization.
Therefore, for this purpose, it is essential that the organic binder be uniformly coated on the surface of the aggregate particles. However, as mentioned above, in the past, the bone phase and the powdered organic binder (phenolic level 1 fat) were kneaded facing each other, so the mixture was macroinitially uniform, even when mixed, all the aggregate particles were mixed. Since the bottom surface cannot be coated with organic binder, the product refractory has -F: high porosity, and the loose organic binder and aggregate particles simply come into contact and are not exposed to sufficient attention. Since some irons do not exert enough force, they have low strength and corrosion resistance. However, in the past, attempts have also been made to use organic binders that are dissolved in an organic solvent in advance and made into a liquid instead of powdered organic binders. However, since organic solvents cause an increase in the permeability of refractory products, the amount of organic solvents used is naturally limited. Therefore, the liquid organic binder has an extremely high viscosity, which makes it difficult to mix it evenly with the aggregate. The present invention aims to solve the above-mentioned conventional problems and provide a method for manufacturing a fire-resistant VII that is uniform, dense, has similar air permeability, has good hardness and strength, and is excellent in hot iron corrosion resistance. It is something to do. Hereinafter, the present invention will be explained in detail.〇 As an example, the aggregate is mainly composed of graphite scales, and the organic binder is phenolic resin. Therefore, the aggregates are graphite scales, anthracite, and coke thread. It contains artificial graphite, carbide powder, metal powder, etc. Flaky graphite is a hexagonal flaky graphite with a crystallite size of G core a-axis k crystallite size or La1OOO^ or more, and a flake size of 3 to 0.3 mm, for example, anthracite-based flaky graphite graphitized at 2700°C or higher. , chirashi graphite by precipitation of metallic molten carbon,
These include raw graphite roasted at 1500°C or higher, naturally produced scaly graphite, etc. This scaly graphite itself has an extremely large natural redundant capacity, with a constraint of 200 kg/cm2. 90% of theoretical density (118~2, Og/possible 3
) or when the constraint is released, the springback property η
There is. In addition, molded products made using only scaly graphite as an aggregate are extremely superior in terms of conductivity, but apart from molding, graphite tends to slip on each other, so lamination is likely to occur, and the porosity is high, resulting in poor tensile strength and resistance. It cannot be used as a blast furnace material because of the pressure and red bean color. Coke-based graphite, anthracite, carbide powder, and metal powder are used to eliminate the drawbacks of scale-like graphite, and coke-based graphite fills the voids in the tortograph graphite skeleton and is interposed as a dense layer, allowing ventilation of the molded product. In addition to reducing the ratio, it can also be used as a structural material.
Artificial graphite for electrode plates and electrodes, metallurgical coke that is semi-graphitized at a temperature of 2,000 to 2,300°C, and aromatic carbon with a carbonization rate of 30% or more. Coke pre-impregnated with an organic compound and then semi-graphitized at the same temperature, or coke impregnated with an organic silicon compound (eg polycarbosilane, etc.) and graphitized at the above temperature. Fr. Cox et al. are also used. Anthracite similarly lowers the air permeability of the molded article and increases its strength, and particularly improves carburization resistance. Carbide reduces the slipperiness of graphite scales, making the molded product more dense and preventing lamination, and metal powders (silicon, aluminum) are carbon sintering agents that bind the carbon of graphite. When combined with β-8LC, it increases the mechanical strength of the molded product and lowers its air permeability. As mentioned above, the bone phase prepared by mixing scale graphite with coke-based graphite, etc. is put into a kneader blender, and then a @kneader solvent such as ethylene glycol is added thereto and stirred, and the surface of the bone phase is coated with an organic solvent. This is also included in the cracks, etc. The organic solvent is then used to dissolve the phenolic resin MVi added to the aggregate and coat the material with this material without fail, as well as to improve adhesion to the aggregate. Although there is no particular limitation, its functions are limited to at least 1. l
In step 1 of molding a product, it is necessary to ensure that it lasts long, and it is also necessary to adjust the viscosity of the melted phenol resin to an appropriate value in order to obtain a molded product with low porosity. From this point of view, it is preferable to use an organic solvent with a boiling point of 150° C. or higher, and for example, glycols such as ethylene glycol, diethylene glycol, and propylene glycol are suitable. Subsequently, finely powdered phenolic resin and
Or add a high viscosity phenol resin solution to 10 to 10
Without applying a pressure of 0 g/rsn2, hold the pressing piece 1T for several minutes to several tens of minutes. As the phenol resin, a thermosetting phenolic resin is used, and a mixture of novolak-type furnace-plastic phenolic pine resin and benzylic ether-type thermosetting phenolic resin in a ratio of 95:5 to 50:50 is particularly preferable. . Novolac-type plastic phenolic resin is a normal solid form of thermal pJ obtained by reacting phenol and formaldehyde at a molar ratio of formaldehyde and phenol of 1 or less under an acidic catalyst such as hydrochloric acid, imitative acid, or citric acid. There is plastic fatliquing. In addition, Benziliskuete/I-fr pH 3 curable phenolic resin is a solid thermosetting resin that acts as a curing agent for novolac-type plastic phenol fats, and is a solid thermosetting resin that acts as a curing agent for novolak-type plastic phenol fats. It is obtained by reacting divalent metal oxides such as divalent metal oxides, borate oxides, or acetic acid group catalysts. For ordinary phenolic resins, the heating temperature during mixing and paper-making is limited to 70 to 80°C or less in order to prevent heat curing during mixing.
Therefore, since it is impossible to keep the melt viscosity of the phenol resin below a certain level, it is unavoidable to mix the material and the phenol resin together. As a result, the bone phase material is destroyed, the raw material composition changes, and it is difficult to uniformly disperse the 1 yen:l fat of phenol. On the other hand, the above-mentioned phenolic resin, which is composed of a novolac-type furnace-plastic phenolic resin and a thermosetting phenolic resin, does not cure at temperatures below 130°C, so the melt viscosity is increased by raising the temperature that much. Since it is possible to increase the strength of the phenolic particles, it is possible to uniformly disperse the phenol resiliency in the aggregate without destroying the bone phase particles, and it is also possible to perform dense molding. By the way, when ethylene glycol is used as an organic solvent and the amount of phenol added is 0.5 to 0.1 times the amount of phenol, the amount of glycol added is usually 70 to 130.
It is desirable to heat it to about ℃. In other words, by doing this, the phenol resin has a viscosity suitable for molding large molded products, the aggregate has a so-called card house structure, and the air permeability of the molded product decreases while its strength increases. It is. In this case, the aggregate should be heated to 130 to 150℃ at the stage of impregnating it with the aggregate KN mechanical solvent.
Heat it to a moderate temperature, then transfer the mixture to another kneader blender, add the phenol to it, and press it. In this way, the mixture will not be heated from the outside while it is being stored, so all the mixtures will be at the same temperature.
There is no need to worry about the phenol resin curing locally, and you can obtain a uniform molded product. Similarly, it is also a method to pre-immerse a portion of the phenol resin in an organic solvent. . In this way, the polar bath agent is impregnated into the bone phase,
Since the phenolic resin is coated on the aggregate, the young fruit shines more reliably than the phenol resin used as a binder. 9. Later on the above)■
The material is filled into a mold, compacted at a pressure of 250 kg/an2 or less, dried in a kettle and fired in a conventional manner. Here, the present invention is characterized by forming NL at a pressure of 250 kg/crn2 or less, and at this pressure, graphite,
In particular, since the coke yarn charred button is almost never crushed, the addition of graphite or vinegar as an aggregate further increases the strength of the molded product and lowers the porosity. Example 2 The compacted powder density was 2ρg by compression of 200 kg/am”
/cm3 or more, and 50 natural L-shaped pieces of flake size or 3 to 0.3 rrm, grain size 4.5 to 0, 1 field, due north i
2.13 or more, coke yarn with a lattice constant of CO6.85A or less, 25 parts of artificial graphite, 15 parts of silicon carbide fine particles with a particle size of 0.074rr+m or less, and 10 parts of metallic silicon in a volume of 30
01 kneader blender, 2.5 seconds of ethylene glycol was added thereto, and the aggregate was kneaded for 10 minutes while heating to 100°C to impregnate the aggregate with ethylene glycol. Transfer to a blender and add 1 tll of novolac type thermoplastic phenol & 4
Adding 18s of a powdered phenolic resin consisting of part o and a benzylic ether type thermosetting phenolic resin lOs,
Do not apply 50 g/am2 (7) pressure to the mixture.
He survived for a minute. The above-mentioned kneaded material was filled into a mold having an internal volume of 013rn3, and a block was molded by pressing at a pressure of 200 kg/crn2 for 5 minutes. The obtained molded body was dried at 250°C in a nitrogen gas atmosphere while preventing oxidation of the bottom surface, and then dried at 130°C in a reducing atmosphere.
O fired in a trench at 0°C Example 2 50 parts of natural lint-like waste lead similar to the center decoration example 1 with a particle size of 4.5~
25 parts anthracite of 0.1r1Tn and particle size 0.074
15 parts of silicon carbide fine particles of less than mm in size and 10 parts of metal powder were placed in a kneader blender with a capacity of 300 kg, and then re-chilled with 2.4 parts of chlorine and 1 part of ethyl alcohol.
, 0 parts of powdered phenolic resin 3s'lr consisting of 30 parts of Noholak type plastic phenolic resin and 20 parts of benzylic ether type thermosetting phenolic resin:
Add the dissolved bath solution, heat to 130°C, and knead for 10 minutes to incorporate the bath solution into the bone phase and evaporate the ethyl alcohol in the bath solution. Transfer to another kneader blender and add novolak water thermoplastic phenolic pine resin 35 & 1. 15 parts of a powdered phenolic resin consisting of and 15 parts of a benzyritta ether type thermosetting phenolic resin were added, and the mixture was incubated for 30 minutes without applying a pressure of 50 g/cm2. Next, fill a mold with an internal volume of 0.3 m3 with L1 stirring material.
A block was molded by applying a pressure of 200 kg/crn2 for 5 minutes.
After drying at 5250℃ while preventing low-temperature oxidation on the surface, it was reduced and fired in an enclosed atmosphere at 1300℃.
Al/rr'lh°C or above, air permeability below 400mm2, strength of 12.0kg/am2 or above, almost no pressurized hot metal permeability, and excellent carburization resistance as blast furnace material. It was suitable. The test method is 50 rrr for the pressurized penetration test method.
After vacuum degassing, sample 1 of n% was immersed in hot metal 2, then gas 4 was pressurized into the container 3, and the pressure was increased to 5 parts kg/crrF. After the test, sample 1 was taken out, cut and polished, and microscopy@
From the observation, the amount of hot metal infiltration was estimated from the area ratio and expressed as an index. Regarding the hot metal resistance test method using the single-sided cooling method, a sample (0
, 15rn3) 7 was constructed and a holding bag was placed in contact with 1550°C hot metal 8. After the test, the amount of erosion loss was actually measured from the surface, and the -7C erosion loss volume index was determined. Pheno-J-resin was added, subjected to 21 kneading, and then molded. 1 By performing preliminary kneading in this manner, low-pressure molding was made possible. Therefore, it is possible to add coke-based artificial graphite, and it is possible to obtain a product with high conductivity, high strength, and almost no air permeability. Explanation Figure 1 shows the pressurized penetration test method - Figure 2 (A) shows the strong hot metal test method by cooling on one side.
B) is a plan view of the same as above. l; Sample 2; Melt 3; Container 4; Gas 5; Outer tube 6; Irregular object 7; Sample 8; Melt pig iron 1 and 2. ”−

Claims (1)

[Claims] An organic solvent or a phenolic resin solution is added to an aggregate made of scaly graphite, artificial graphite, anthracite, or a mixture thereof and other additives and kneaded, and the aggregate is impregnated with the organic solvent or phenolic resin solution. Next, a phenol resin is added to the above mixture and kneaded, and the kneaded product is further filled into a mold and heated at a pressure of 50 to 500) cg/2.
The obtained molded product was held for 0 minutes and molded, and the molded product was heated to 150 to 300% while suppressing low-temperature oxidation of the surface in an inert gas atmosphere
After drying at 1000-1500°C in a reducing atmosphere.
A method for producing carbon refractories for blast furnaces, which is characterized by heating to ℃ and firing. The compacted powder density is 2.0363 due to 200 kg shoulder compression.
Scale graphite with a sharp flake size of 3 to 0.3 plates 40 to 40
60 parts, particle size 4.5-0, ■ 1 sub-Corknu-based artificial graphite
Car 3411 with a particle size of 5 to 30 parts and a particle size of 0,074 rrm or less
Add 5 to 15 parts of an organic solvent in which 0 to 5 parts of phenolic resin is dissolved to an aggregate consisting of 0 to 20 parts and 5 to 15 parts of metal powder, knead to impregnate the aggregate with the organic solvent, and then add to the above mixture. 8. The method for producing carbon refractories for blast furnaces according to claim 7, which comprises adding 10 to 20 parts of a phenol resin and kneading the mixture in a kneader blender under a pressure of LO to 100 g/cm. Scale graphite is hexagonal flaky scale graphite with an a-axis crystallite size of La10006 or more, anthracite scale graphite graphitized at 2700°C or higher, chirashi graphite produced by precipitation of metallic molten carbon, and naturally produced refined graphite. Method O for producing carbon refractories for blast furnaces according to claim 2, characterized in that the carbon refractories for blast furnaces are scaly graphite or green graphite roasted at 1500°C or higher.The coke-based artificial graphite has a particle crushing strength of 200 kg/c, m
``Artificial graphite for electrolytic plates and electrodes having 2000～
Metallurgical coke semi-graphitized at a temperature of 2300°C, petroleum coke, pitch, coke, metallurgical coke impregnated with an aromatic carbonaceous organic compound with a carbonization rate of 30% or more or an organosilicon compound such as Polycrystalline A or Hongran. 200 later
3. The method for producing a carbon refractory for blast furnaces according to claim 2, wherein the coke is semi-graphitized at a temperature of 0 to 23 oo<0>C.