阅读说明：本技术 一种能自流的高炉用高导热炭质浇注料 (High-thermal-conductivity carbon castable capable of flowing automatically for blast furnace ) 是由 徐国涛 向武国 张庆喜 张洪雷 刘黎 胡胜修 何可 于 2020-05-20 设计创作，主要内容包括：一种能自流的高炉用高导热炭质浇注料,其组分及wt%为：粒度5-1mm的碳质骨料35～55%,粒度3-0.1mm的碳化硅骨料5～30%,粒度≤0.074mm的电煅无烟煤细粉10～20%,粒度≤0.074mm的电极粉3～15%,粒度≤0.005mm的氧化铝微粉3～8%,粒度≤0.074mm的碳化硅细粉5～20%,粒度≤0.074mm的金属硅粉3～8%,纳米级碳粉0.1～3%,铁铝酸钙水泥5～10%,减水剂0.05～1.5%。本发明流动性好、施工方便简单,导热系数在15W/m·K以上,能提高高炉炉底水冷管周围炭质浇注料的质量,利于水冷效果的传递。(A high heat conduction carbon castable for a blast furnace capable of automatically flowing comprises the following components in percentage by weight: 35-55% of carbonaceous aggregate with the particle size of 5-1mm, 5-30% of silicon carbide aggregate with the particle size of 3-0.1mm, 10-20% of electrically calcined anthracite fine powder with the particle size of less than or equal to 0.074mm, 3-15% of electrode powder with the particle size of less than or equal to 0.074mm, 3-8% of alumina micro powder with the particle size of less than or equal to 0.005mm, 5-20% of silicon carbide fine powder with the particle size of less than or equal to 0.074mm, 3-8% of metal silicon powder with the particle size of less than or equal to 0.074mm, 0.1-3% of nano carbon powder, 5-10% of calcium alumino. The invention has good fluidity, convenient and simple construction, and thermal conductivity coefficient of more than 15W/mK, can improve the quality of the carbonaceous castable around the water cooling pipe at the bottom of the blast furnace, and is beneficial to the transmission of water cooling effect.)

1. A high heat conduction carbon castable for a blast furnace capable of automatically flowing comprises the following components in percentage by weight: carbonaceous aggregate having a particle size of 5 to 1 mm: 35-55%, 5-30% of silicon carbide aggregate with the granularity of 3-0.1mm, and electrically calcined anthracite fine powder with the granularity of less than or equal to 0.074 mm: 10-20%, electrode powder with the granularity less than or equal to 0.074 mm: 3-15%, alumina micropowder with granularity less than or equal to 0.005 mm: 3-8%, silicon carbide fine powder with the granularity less than or equal to 0.074 mm: 5-20%, and metal silicon powder with the particle size less than or equal to 0.074 mm: 3-8%, nano-scale carbon powder: 0.1-3%, calcium aluminoferrite cement: 5-10% of a water reducing agent: 0.05-1.5%; adding water in the total weight of the raw materials: 4.5 to 7.5 percent.

2. The high thermal conductivity carbon castable for self-flowing blast furnaces as claimed in claim 1, wherein: the calcium aluminoferrite cement is cement consisting of mineral phases with calcium aluminoferrite accounting for not less than 75% by weight.

3. The high thermal conductivity carbon castable for self-flowing blast furnaces as claimed in claim 1, wherein: the carbon aggregate has a fixed carbon content of not less than 90%, and a graphitization degree of not less than 70% and not more than 95%.

4. The high thermal conductivity carbon castable for self-flowing blast furnaces as claimed in claim 1, wherein: the content of silicon carbide in the silicon carbide aggregate and the silicon carbide fine powder is not lower than 97%.

5. The high thermal conductivity carbon castable for self-flowing blast furnaces as claimed in claim 1, wherein: the water reducing agent is a carboxylate water reducing agent or a naphthalene sulfonate water reducing agent.

Technical Field

The invention relates to the field of refractory materials for blast furnaces, and mainly relates to a high-thermal-conductivity carbon castable for a blast furnace bottom.

Background

The blast furnace is the foundation for stable and smooth operation of iron-making production, and the most important parts for ensuring the stable and smooth operation of the blast furnace hearth are the carbon bricks and the water cooling system. The carbon brick and the molten iron are not easy to infiltrate, and the erosion resistance is strong; obviously, the water cooling is the key for ensuring the long-life operation of the carbon bricks. In the process of building the blast furnace bottom, after the water cooling pipe is laid, the carbon ramming mass is mostly adopted for leveling in the prior art, carbon brick joints are filled, and in order to further ensure the water cooling effect, the carbon ramming mass is required to have high heat conductivity coefficient, certain strength and good construction quality.

The high-heat-conductivity carbon ramming material can effectively cool a furnace lining of a cooling system of a blast furnace, and guarantee long-life and stable operation of the blast furnace, but due to the fact that the ramming material is large in relation with construction process and construction quality and has many human influence factors, enterprises begin to research and apply carbon-containing castable in China and abroad, heat-conductivity system data are only less than 10 w/m.k in leakage, some are not less than 16.0 w/m.k in leakage, and the using effect of the ramming material is better than that of the ramming material. If retrieved:

the name is 'carbonaceous ramming mass used at the bottom and hearth of a blast furnace', which comprises the following components: 30-45wt% of industrial synthetic graphite with the granularity of 1-5 mm; 6-22wt% of industrial synthetic graphite with the granularity of less than 0.074 mm; 10-30wt% of flake graphite with the granularity of 1-5 mm; 8-20wt% of high-carbon composite micro powder; 10-15wt% of modified composite thermosetting resin. Stirring the industrial synthetic graphite with the granularity of 1-5mm and the high-carbon composite micro powder at medium speed, and then adding 5-8wt% of modified composite thermosetting resin; stirring at medium speed and high speed, pouring the rest raw materials and the rest modified composite thermosetting resin, and stirring at high speed to obtain the final product. The bulk materials of the ramming material in a cold state must be formed by ramming, and the defects of high labor intensity and troublesome construction exist.

The Chinese patent publication No. CN110373507A discloses a method for forming a casting lining body on the inner side of a blast furnace hearth side wall carbon brick lining body, and the invention mainly relates to a working procedure and a method arrangement for casting the lining body on the inner side of the hearth side wall carbon brick lining body. Pouring refractory castable between the carbon brick lining body and the bricked refractory bricks on the side wall of the hearth, wherein the upper surface of the refractory castable is not higher than the upper surface of the bricked refractory bricks. The material of the casting material is not clearly described, and the casting material aims at the side wall of the hearth and can not be used between water-cooled tubes at the bottom of a more complicated furnace, so that the situation is unknown.

Chinese patent publication No. CN110282990A discloses a castable for a blast furnace hearth and a blast furnace hearth side wall lining made of the same, which comprises the following components: the mass percentage of the components (a) to (c): (a) main material: 74-84%, (b) mix: 12-17%, (c) conjugate: 4 to 10 percent; the main material comprises the following raw materials in percentage by mass: corundum material with granularity of 5-10 mm: 20-28%, corundum material with particle size of 2-5 mm: 19-27%, corundum material with particle size of 0-2 mm: 24-30%, silicon carbide material with granularity of 0-2 mm: 18-32%,35MF kyanite material: 1 to 2 percent; the mixture is composed of the following raw materials in percentage by mass: alumina micropowder: 58-69%, silicon micropowder: 18-24%, ball asphalt: 9-16%, calcium aluminate cement: 2.5 to 4.5 percent. The side wall of the blast furnace hearth comprises a carbon brick masonry, a ceramic cup and a lining body which is positioned between the carbon brick masonry and the ceramic cup and is cast by the castable, and the thickness of the lining body in the radial direction of the blast furnace is 100-300 mm. The castable has excellent filling property and low water content, eliminates pores caused by evaporation of a large amount of water, and has excellent corrosion resistance of a blast furnace lining after being poured, but the castable mainly comprises corundum, blue-crystal stone and a small amount of silicon carbide aggregate, and has high asphalt adding amount, so that the castable is easy to soften and bubble in the operation of a blast furnace, the heat conductivity is difficult to ensure, the service performance is difficult to ensure if the castable is used at the bottom of the blast furnace, and the castable is not suitable for the bottom of the blast furnace.

The Chinese patent publication No. CN110041086A discloses a flexible carbon castable for a furnace bottom leveling layer, which comprises the following components in percentage by mass: 61-65% of high-power graphite particles; 10-20% of high-power graphite powder; 3-5% of active alpha-alumina micro powder; 2-5% of natural crystalline flake graphite; 7-14% of pure aluminate cement; 1-2% of a dispersing agent. Although the document does not produce substances harmful to the environment and does not have any harm to the bodies of constructors, as the main raw materials are graphite powder and natural crystalline flake graphite, the graphite is not soaked in water, is easy to float on the surface of casting slurry and is difficult to form a uniform casting layer; the addition amount of the pure aluminate cement is 7-14%, the water consumption is large, the cement binding material is easy to delaminate, and the graphite floats to the surface; in addition, the temperature of the furnace bottom is low, water leakage of a water-cooling pipe exists sometimes, the calcium aluminate cement is difficult to sinter, and the calcium aluminate cement is easy to pulverize for a long time.

Chinese patent publication No. CN101823894A discloses "a baking-free carbonaceous ramming mass and a preparation method thereof", the carbonaceous ramming mass including: particle raw materials, micro powder raw materials, modified binders and phenolic resin; the application finds that the one-time ramming time of the baking-free ramming material is 15-25 minutes, so that the labor intensity and the labor time can be saved; the iron can be discharged after the iron is rammed without baking, so that the baking cost is saved; the content of benzopyrene is less than or equal to 0.05 percent, and the environment is not polluted; the one-time iron-passing period is 5-10 ten thousand tons, and the service life is prolonged. The castable disclosed in the document is not flowable and is not suitable for a part with a water-cooled tube at the bottom of the furnace.

Chinese patent publication No. CN101671548 discloses a high thermal conductivity graphite ramming mass, which comprises the following raw materials in parts by weight: 20-30 parts of electrolytic graphite, 1-5 parts of carbon black, 30-55 parts of artificial graphite, 3-8 parts of tung oil, 3-8 parts of sodium silicate and 0.5-3 parts of aluminum dihydrogen phosphate. The invention has the advantages that the sodium silicate is alkaline, the aluminum dihydrogen phosphate is acidic, the tung oil is insoluble in water, and the acid-base reaction can bubble into a honeycomb body at high temperature.

The Chinese patent CN201910393433.0 discloses a flexible carbon castable for a furnace bottom leveling layer, which comprises, by mass, 61-65% of high-power graphite particles, 10-20% of high-power graphite powder, 3-5% of active alpha-alumina micropowder, 2-5% of natural flake graphite, 7-14% of pure aluminate cement and 1-2% of a dispersing agent. The material used has the advantages of simple construction operation, certain thixotropy, and can be quickly flattened in time after vibration molding, thereby saving a large amount of construction period. The natural crystalline flake graphite is used, is not soaked in water, is easy to float to the surface of slurry in the casting process, has the melting point of more than 1650 ℃ of pure aluminate cement, is completely dependent on that graphite particles cannot be sintered, is easy to pulverize in the presence of water, and cannot play a role in heat conduction and cooling of a leveling layer.

From the literature results of the above search: the high-heat-conductivity carbon castable for blast furnaces reported by domestic literature is few, and only reports that graphite granules, graphite powder, alpha-alumina micropowder, natural crystalline flake graphite, pure aluminate cement and a dispersing agent are used; one problem is that graphite and water are difficult to infiltrate, cement bonding is easy to float to the surface in a layered mode, and the other problem is that the temperature of the furnace bottom is low, water leakage of a water-cooled tube exists sometimes, cement is difficult to sinter by virtue of calcium aluminate, and the cement is easy to pulverize for a long time.

Disclosure of Invention

Aiming at the defects of low strength, complex construction, high labor intensity, and high degree of correlation between material performance and construction mode and construction quality of the existing carbon ramming mass in the prior art, the invention provides the self-flowing high-thermal-conductivity carbon castable for the blast furnace, which has the advantages of good fluidity, convenient and simple construction, and thermal conductivity coefficient of more than 15W/m.K, thereby improving the construction quality of the furnace lining at the bottom of the blast furnace.

The measures for realizing the aim are as follows:

a high heat conduction carbon castable for a blast furnace capable of automatically flowing comprises the following components in percentage by weight: carbonaceous aggregate having a particle size of 5 to 1 mm: 35-55%, silicon carbide aggregate with the granularity of 3-0.1 mm: 5-30%, electrically calcined anthracite fine powder with the particle size less than or equal to 0.074 mm: 10-20%, electrode powder with the granularity less than or equal to 0.074 mm: 3-15%, alumina micropowder with granularity less than or equal to 0.005 mm: 3-8%, silicon carbide fine powder with the granularity less than or equal to 0.074 mm: 5-20%, and metal silicon powder with the particle size less than or equal to 0.074 mm: 3-8%, nano-scale carbon powder: 0.1-3%, calcium aluminoferrite cement: 5-10% of a water reducing agent: 0.05-1.5%; adding the following raw materials in percentage by weight: 4.5 to 7.5 percent.

It is characterized in that: the calcium aluminoferrite cement is cement consisting of mineral phases with calcium aluminoferrite accounting for not less than 75% by weight.

It is characterized in that: the carbon aggregate has a fixed carbon content of not less than 90%, and a graphitization degree of not less than 70% and not more than 95%.

It is characterized in that: the content of silicon carbide in the silicon carbide aggregate and the silicon carbide fine powder is not lower than 97%.

It is characterized in that: the water reducing agent is a carboxylate water reducing agent or a naphthalene sulfonate water reducing agent.

Mechanism and action of the main raw materials in the invention

The invention adopts the carbonaceous aggregate with the granularity of 5-1mm, the fixed carbon content of the carbonaceous aggregate is not less than 90 percent, and the graphitization degree of the carbonaceous aggregate is not less than 70 percent. Because the carbon content of the carbonaceous aggregate is low, the carbonaceous aggregate is easy to become crisp and easy to pulverize at the bottom of the blast furnace; the low graphitization degree results in low heat conductivity, poor water cooling effect on water cooling pipes and unfavorable long service life of the blast furnace. High carbon content, no influence, too high graphitization degree, problem of wettability with water and poor dispersion.

The silicon carbide aggregate with the granularity of 3-0.1mm is adopted, the silicon carbide content is not lower than 97%, the silicon carbide content is lower than 97%, the compactness is influenced, the thermal conductivity is poor, and the thermal conductivity coefficient of the carbon castable is influenced; higher than 97% is favorable for compactness and heat conductivity.

The electrically calcined anthracite fine powder with the granularity less than or equal to 0.074mm is adopted, and is more than 0.074mm, so that the electrically calcined anthracite fine powder has insufficient density, too light weight, insufficient density of the casting material, low strength and easy water absorption and pulverization; when the particle size is less than or equal to 0.074mm, the dispersion effect is facilitated.

The electrode powder with the granularity less than or equal to 0.074mm is adopted, because the electrode powder is larger than 0.074mm, the compactness is insufficient, the weight is too light, the density of the casting material is insufficient, the strength is low, and the electrode powder is easy to absorb water and pulverize; when the particle size is less than or equal to 0.074mm, the dispersion effect is facilitated.

The aluminum oxide micro powder with the granularity less than or equal to 0.005mm is adopted, because the aluminum oxide micro powder is more than 0.005mm, the aluminum oxide micro powder is difficult to compact and sinter at low temperature, the strength is low, and the castable is easy to pulverize; when the granularity is less than or equal to 0.005mm, the dispersion of the micro powder is facilitated, and the low-temperature sintering of the casting material is facilitated.

The silicon carbide fine powder with the granularity less than or equal to 0.074mm is adopted, and is difficult to sinter and low in heat conductivity coefficient because the silicon carbide fine powder is larger than 0.074 mm; when the granularity is less than or equal to 0.074mm, the strength of the castable matrix is improved, and the heat conductivity coefficient is improved.

The metal silicon powder with the particle size less than or equal to 0.074mm is adopted, because the silicon carbide is easy to oxidize, and the added silicon powder is more than 0.074mm, is difficult to oxidize and cannot play a role in protection; when the granularity is less than or equal to 0.074mm, the antioxidant effect of the silicon carbide carbon is facilitated.

The nano-scale carbon powder is adopted in the invention, because the nano-scale carbon powder has good dispersibility, the gap is easy to be densely filled, and the heat conductivity coefficient is improved. Carbon powders that are not nanoscale are less effective.

The invention adopts the calcium ferroaluminate cement consisting of mineral phases with the weight percentage not less than 75 percent, because the calcium ferroaluminate cement has proper solidification speed, low sintering temperature and high strength, and the calcium ferroaluminate cement consisting of mineral phases with the calcium ferroaluminate less than 75 percent has insufficient strength and too high solidification speed; the calcium aluminoferrite cement consisting of mineral phases with calcium aluminoferrite content not less than 75% has low sintering temperature and proper setting speed.

Compared with the prior art, the invention has good fluidity, convenient and simple construction, and the heat conductivity coefficient of more than 15W/m.K, can improve the quality of the carbon castable around the water cooling pipe at the bottom of the blast furnace, and is beneficial to the transmission of the water cooling effect. The blast furnace using the carbon ramming material has the problem that the temperature of the furnace bottom is increased when some blast furnaces are put into operation for less than 2 years due to improper construction and poor ramming material quality. The carbon castable is used, the heat conductivity coefficient of the carbon castable is improved by 3-5 w/m.k compared with that of the common carbon ramming material, and the service cycle of the carbon castable is not less than 12 years.

Drawings

Fig. 1 is a schematic diagram of the carbon castable material of the present invention after self-flow laying.

Detailed Description

The present invention is described in detail below: