Magnesia-carbon castable and preparation method thereof

Abstract

The invention relates to a magnesia-carbon castable and a preparation method of the magnesia-carbon castable. The technical scheme is as follows: a carbon raw material and an antioxidant are prepared at the mass ratio of (3-6): (1), and co-grinding; performing thermal treatment on co-grinded premix powder at the temperature of 800-1400 DEG C and under the carbon-burying condition, then finely grinding the premix powder to be smaller than 0.37mm to obtain the carbon-coated mixing powder; (2), the raw materials of magnesia-carbon castable and the mass contents of the magnesia-carbon castable are as follows: 68-72% of magnesia particles, 10-15% of magnesia fine powder, 3-6% of alpha-Al2O3 micro powder, 3-6% of SiO2 micro powder, 1-8% of coated carbon mixing powder, 1-3% of asphalt powder, 1-2% of Si powder, 0.3-0.6% of B4C, 0.03-0.1% of explosion-proof fiber, and 0.2-0.3% of water reducer; and (3), weighing the raw materials according to the contents, uniformly mixing the raw materials, then adding water which is 5.5-6.8wt% of the raw materials, uniformly stirring the mixture, forming, maintaining, demolding, and then baking the mixture. The magnesia-carbon castable prepared by the method has the characteristics of high strength as well as excellent oxidation resistance, residual permeation resistance and corrosion resistance performances.

Description

technical field [0001] The invention belongs to the technical field of castables, and in particular relates to a magnesium-carbon castable and a preparation method thereof. Background technique [0002] Ladle is an important container in the metallurgical industry, which plays the role of storing, transporting and processing molten steel. At the same time, it also has the dual task of refining outside the furnace, which directly affects the normal production of steelmaking. With the improvement of the life of the converter, the increase of the continuous casting ratio and the progress of the refining technology outside the furnace, the ladle is under increasingly harsh operating conditions such as large capacity, various steel types, high temperature, and long time, and the operating environment of the slag line is particularly harsh . At present, the use of MgO-C bricks for the ladle slag line is still the mainstream, but there are also disadvantages such as the service li...

AI Technical Summary

Problems solved by technology

However, the density of particles or small pellets is very low, and a large number of residual pores lead to a large number of irregularly distributed pores in the final castable, which leads to a decrease in corrosion resistance and oxidation resistance

The hydrophilicity of graphite can be improved by adding surfactants, but this improvement is limited, and it is still difficult to add a large amount of graphite

[0004] In the patented technology of "sol-bonded carbon-containing refractory castable and its preparation method" (ZL03125319.9), the carbon raw material is modified by pre-mixing and briquetting with refractory fine powder, and then granulating after embedding carbon and firing. The process is complex, the amount of water added is large and the strength of the castable is low

"MgO-SiC-C refractory castable based on forsterite-C and its preparation method" (CN200810048985.X) patented technology, firstly use the resource-rich forsterite ore powder and C powder to synthesize MgO- The SiC-C raw material is crushed into a certain particle size and then introduced into the castable. Although it has good slag erosion resistance, the process consumes a lot of energy, and the performance of the castable will fluctuate with the grade of forsterite

"Nano Al 2 o 3 Film-wrapped carbon-spinel refractory castable and its preparation method" (ZL200810079799.2) and "Nano Al 2 o 3 , MgO film-wrapped carbon-spinel magnesia refractory castable and its preparation method” (CN200910136836.3) patent technology, all use nano-sol technology to wrap coke powder, because the nano-coating layer will be damaged by friction during the stirring process To a certain degree of damage, in the subsequent drying and use process, if the heating rate is slightly faster, the coating layer will crack during the process of dehydration and conversion of the sol into oxides. Therefore, the oxidation resistance of the castable is poor and cannot fully Play the role of carbon

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