KR100310050B1 - method for forming canbon brick with fire resistance and corrosion resestance - Google Patents

Abstract

The present invention has excellent properties for acid tanks of various chemical plants, refractory materials of melting furnaces, etc. having acid resistance, corrosion resistance, and heat resistance, and in the manufacture of carbon bricks suitable for reducing the production cost according to the simplification of the process and low temperature heat treatment. It is about.

Accordingly, the present invention is 30-95 parts by weight of artificial graphite made by heating a pitch or coal tar, 2-25 parts by weight of metal silicon (Si), amorphous carbon, impression graphite or natural graphite, at least one of metal oxide 2-20 parts by weight of one or more, 3-15 parts by weight of the thermosetting resin after kneading and molding for a method of producing a fire-resistant and corrosion-resistant carbon brick, characterized in that the firing 3-72 hours at a temperature of 1,200-1700 ℃ in a reducing atmosphere Technology.

Description

Method for forming fire and corrosion resistant carbon bricks {method for forming canbon brick with fire resistance and corrosion resestance}

The present invention relates to a carbon brick, and more particularly, by heat-treating at a low temperature by using a raw material such as a main component and a metal silicon, which is an artificial graphite raw material made by heating a pitch or coal tar, the content of impurities is increased. It is low and excellent in acid resistance and strength characteristics compared to the existing carbon brick, and relates to a method of manufacturing a carbon brick suitable for the production cost reduced by the simplification of the manufacturing process and the elimination of the graphitization process at a high temperature.

Carbon brick has excellent acid resistance, corrosion resistance, and thermal conductivity, so it is possible to recover acid tanks of various chemical plants, blast furnace refractory materials, induction furnaces for steel and non-ferrous metals, and precious metals in nonferrous metal smelting plants. Chimney and its use is also varied.

There are many methods for producing carbon bricks. Generally, starting materials are hot kneaded thermoplastics (eg, pitch tar) based on amorphous carbon, such as needle cokes or low temperature heat treated cokes, as non-graphite carbon. After the hot forming, the graphite is heated in an electric furnace at about 1,500 to 3,000 ° C. to form amorphous carbon.

Such a conventional method has a disadvantage in that the manufacturing cost is high, such as the use of 20% or more of thermoplastic resin for 2-4 days for hot kneading and energizing heating and 1-2 weeks for cold, such as a long and complicated manufacturing process. In particular, carbon bricks containing about 92% of the carbon used in acid tanks in chemical plants have high impurity content by using low needle coke or low temperature heat-treated coke as starting materials, and graphitization during heat treatment below 1,600 ℃. Because of the low level, it is highly likely to be vulnerable when used for a long time depending on the type of acid used for the purpose of strength reinforcement.

The present invention is to solve the above-mentioned problems, using the artificial graphite main component made by heating the pitch (pitch) or coal tar (coal tar) as a starting material and metal silicon and thermosetting resin at a lower temperature than conventional It is an object of the present invention to obtain a carbon brick having an excellent acid resistance and strength characteristics as well as a reduction in manufacturing cost by simplifying the manufacturing process, such as being advantageous in terms of energy saving and cold forming by heat treatment.

The present invention for achieving the above object is 30-95 parts by weight of artificial graphite made by heating the pitch (pitch) or coal tar (coal tar), 2-25 parts by weight of metal silicon (Si), amorphous carbon, impression graphite or natural 2-20 parts by weight of at least one of graphite and metal oxides, 3-15 parts by weight of thermosetting resins are kneaded and then fired for 3 to 72 hours at a temperature of 1,200-1,700 ° C. in a reducing atmosphere. It is made of brick manufacturing method.

In the present invention, carbon and metal silicon react during firing to produce beta silicon carbide (β-SiC) and silicon oxynitride (Si ₂ ON ₂ ) between the particles and the particles to determine the particles and particles, and in the firing atmosphere Carbon monoxide (CO) and metal silicon react to produce beta silicon carbide. In the above-mentioned reducing atmosphere, air is mixed and nitrogen is mixed in the air. Therefore, silicon oxynitride (Si ₂ ON ₂ ) is produced by heat treatment in such a reducing atmosphere.

The beta-type silicon carbide thus produced is well developed in whiskers or fibers in the pores of the carbon brick to further strengthen the bond strength.

That is, silicon carbide whiskers or fibers are produced during the firing process to bond the graphite large particles and small particles more strongly.

Therefore, carbon bricks having excellent characteristics could be manufactured by a simpler manufacturing process and a lower manufacturing cost than products manufactured by conventional methods of graphitization.

In the present invention, the firing temperature is significantly lowered. The reason for this is that in the conventional method, graphitization, which is a plate-like layered structure using needle-like coke, which is an amorphous carbon raw material, starts at 1,500 ° C or higher, and at 2,000 ° C or higher, such graphitized crystal structure. In the production method of the present invention, since the starting material itself has the above graphitized crystal structure, a separate graphitization step is not necessary and the added metal silicon is graphitized by producing beta silicon carbide and silicon oxynitride during firing. The combination of particles and particles with a crystalline structure showed better strength properties than conventional carbon bricks.

The following is described according to the embodiment.

(Example 1)

Raw material blending ratio, artificial graphite 90 parts by weight, metal silicon 5 parts by weight, impression graphite 5 parts by weight

1-10 parts by weight of binder

Particle Size Distribution: Metal Silicon 10㎛

Total particle size distribution of raw materials excluding binder: 1mm or more 35%, 1-0.212mm 30%, 0,212mm or less 35%

Firing condition, temperature: 1,500 ℃

Time: 10 hours

The above conditions are shown in the sample (C) of (Table 1), and the raw materials are blended and kneaded in a mixer without pressure, and the mixed clay is aged at room temperature for 24 hours.

After the maturation of the mixed mixed clay is molded into the shape and mold release indicated in the Korean Industrial Standards, the natural drying is performed at room temperature for about one day.

The naturally dried molded body is dried at 100-200 ° C. for 24 hours.

The dried molded body is calcined at 1,500 ° C for 10 hours.

Firing kilns are available in both kilns and tennel kilns, and when fired in tunnel kilns, mass production functions, resulting in greater productivity and quality uniformity.

The physical properties shown by the above conditions were found to be superior to the porosity of 18%, the absorption rate of 9.5%, bending strength 220㎏ / ㎠, compressive strength 300kg / ㎠.

(Example 2)

Raw material blending ratio, artificial graphite 80 parts by weight, impression graphite 10 parts by weight, metal silicon 10 parts by weight

1-10 parts by weight of binder

Particle Size Distribution: Metal Silicon 10㎛

Total particle size distribution of raw materials excluding binder: 1mm or more 35%, 1-0.212mm 25%, 0,212mm or less 40%

Firing condition, temperature: 1,500 ℃

Time: 10 hours

The said conditions showed the sample (a) of (Table 1), and other conditions were made the same as Example 1.

The physical properties shown by the above conditions were porosity 17%, absorption 9%, bending strength 180㎏ / ㎠, compressive strength 350㎏ / ㎠ showed better than the existing technology.

Table 1

division end I All la hemp bar four Ah character car Ka Ta wave Ha Artificial Graphite Raw Material 98 95 90 85 85 83 83 80 80 80 65 65 55 55 Metal silicon 2 3 5 5 7 7 10 10 13 15 15 20 20 25 Impression 0 2 5 10 8 10 7 10 7 5 20 15 25 20 Binder (external addition) 1-10 parts by weight Firing temperature (℃) 1,200-1,600 ℃ Firing time (H) 3-72

The conditions according to the other examples shown in Table 1, including Examples 1 and 2 (Samples: c, a), were carried out. (Table 2) The same result was obtained.

As described above, the present invention can obtain a product having excellent properties by producing carbon bricks by a method different from the existing technology.

The present invention is considered to be an advantageous method in terms of energy saving since the manufacturing process is simpler than the existing method and does not require a higher temperature than the existing method in the manufacturing process.

In addition, by using the thermosetting resin in the kneading or molding drying process, the kneading molding process is generally possible in the cold like kneading molding of the refractory brick, and the drying process is drastically reduced for a long time by using the conventional thermosetting resin. Could.

Table 2

division end I All la hemp bar four Ah character car Ka Ta wave Ha Volume specific gravity 1.72 1.72 1.72 1.71 1.73 1.73 1.72 1.73 1.75 1.78 1.80 1.81 1.85 1.87 Porosity (%) 18.2 18.8 18 19 19.5 20 19 17 21 20.5 20 22.3 22 23 Absorption rate (%) 9.7 10 9.5 10 10.5 11 9.8 9 10.5 11 10.8 11 11 12 Bending strength (㎏ / ㎠) 158 179 220 154 178 179 196 211 191 175 165 151 130 141 Compressive strength (㎏ / ㎠) 245 315 443 293 346 295 320 415 382 380 376 380 392 311

As described above, the present invention, unlike the conventional method, adds artificial graphite raw material and metal silicon made by heating pitch or coal tar, kneading with thermosetting resin, and forming at low temperature in a reducing atmosphere after molding, thereby simplifying the process and saving energy. As a result, carbon bricks having excellent acid resistance and strength characteristics can be obtained while reducing production costs.

Claims (1)

30-95 parts by weight of artificial graphite made by heating pitch or coal tar, 2-25 parts by weight of silicon (Si), amorphous carbon, impression graphite or natural graphite, at least one or more of metal oxides 2 -20 parts by weight, thermosetting resin 3-15 parts by weight kneading and molding, and then fired for 3 to 72 hours at a temperature of 1,200-1,700 ℃ in a reducing atmosphere characterized in that the manufacturing method of the fire-resistant and corrosion-resistant carbon brick.