Composite carbon fiber reinforced iron ditch castable

Abstract

The invention discloses a composite carbon fiber reinforced castable for an iron trough. The castable is formed by mixing main materials and additives, wherein the main materials comprise, in weight percent, 20-30% of special grade high alumina, 15-25% of brown aluminum oxide, 5-10% of white corundum, 10-15% of dense corundum, 15-25% of silicon carbide, 2-5% of ultra-fine silica powder, 4-10% of alpha-Al2O3 micro-powder and 4-6% of pure aluminum silicate cement. The additives comprise short carbon fibers, carbon fiber powder, silicon metal powder, ball pitch, water-soluble polyvinyl alcohol fibers, carboxymethyl cellulose powder, organic silicon defoaming agent powder, sodium tripolyphosphate and water reducing agents FS20. The sintering condition of the castable under working conditions is improved, the high-temperature mechanical property and heat shock stability of the castable are enhanced, and the manufacturing cost of the castable is reduced.

Description

technical field [0001] The invention relates to a refractory castable for a blast furnace tapping trough, in particular to a composite carbon fiber reinforced iron trough castable. Background technique [0002] The blast furnace tapping chute is a channel that guides the flow of high-temperature molten iron and slag during the blast furnace tapping process. Therefore, the lining of the blast furnace tapping chute is in direct contact with high-temperature molten iron and slag during the actual production process, and withstands the erosion of flowing molten iron and slag , wear, chemical erosion and rapid cooling and rapid heating caused by frequent alternate iron tapping, resulting in erosion and wear of molten iron and slag on the surface of refractory materials, erosion and melting loss, stress cracks, penetration and structural damage. Therefore, strict technical requirements are put forward for the high-temperature mechanical strength, chemical corrosion resistance and ...

AI Technical Summary

Problems solved by technology

[0003] With the continuous development of blast furnace smelting technology, blast furnaces are developing in the direction of large-scale, high-efficiency, automation and long life. The further deterioration of the working conditions has aggravated the damage process of the iron trough refractory and the difficulty of longevity

At present, Al 2 o 3 -SiC-C castables, the main raw material is high-purity corundum, and the main carbon source is spherical pitch; although these main raw materials provide castables with excellent high-temperature performance and corrosion resistance, high-purity corundum materials are expensive and not It is conducive to the cost reduction of castables. At the same time, the sintering temperature of high-purity corundum is high, which is not conducive to the formation of ceramic bonding and the improvement of thermal shock stability under the working conditions of castables; in addition, spherical pitch will release during the baking process. Toxic smoke forms yellow smoke and causes environmental pollution; after thermal cracking, the residual carbon content is low, the pores are large, and the oxidation resistance is poor. In addition, during the baking process of the castable, the spherical asphalt softens and penetrates, causing the through hole of the castable to be blocked. It is difficult to discharge the water vapor during baking, and it is easy to cause the pouring body to burst

For this reason, "an Al 2 o 3 -SiC-C iron channel castable and its preparation method" (CN103011868A) patent technology discloses a preparation method of iron channel castable with catalyst added. This method uses the action of catalyst at high temperature to generate carbon whiskers in situ to improve iron The high-temperature service performance of the trench material, carbon whiskers have the advantages of high strength and elastic modulus, high temperature resistance, and corrosion resistance, which can improve the service performance and prolong the service life of the iron trench castables, but its main defect lies in the formation of carbon whiskers The quantity is limited, and the price of the catalyst is expensive, which is not conducive to the realization of industrial production

"A castable for blast furnace iron trough containing carbon fiber and its preparation method" (CN 104072177 A) discloses a castable for iron trough with carbon fiber addition of 0.2-0.6wt% and its preparation method, the main carbon source is still spherical Asphalt, in which carbon fiber is made into carbon fiber monofilament through fiber opening process, and then TiO 2 Sol impregnation modification; therefore, the preparation process of castables is complicated, and there is no specific method for uniform dispersion of carbon fibers

"Improved Refractory Castable for Blast Furnace Tapping Tunnel" (CN1260372C) discloses a casting material for iron trench whose main aggregate is composed of dense fused corundum, sintered tabular corundum and fused brown corundum. Coordinating effect, improving thermal shock stability of castables, reducing thermal shock cracks and spalling damage of castables, but insufficient disclosure of other components, and insufficient disclosure of other performance indicators, which is not conducive to large-scale promotion of technology

It can be seen that domestic scholars use Al 2 o 3 - A lot of work has been done to improve the performance of SiC-C castables, but there is still a lot of room for improvement in the cost reduction of castables and the main carbon source