Al2O3-MgO-SiC-C brick for ladle working linings and preparation method thereof

Abstract

The invention discloses an Al2O3-MgO-SiC-C brick for ladle working linings and a preparation method thereof. The Al2O3-MgO-SiC-C brick comprises the following raw materials in parts by weight: 35-55 parts of high alumina bauxite particles, 10-20 parts of corundum particles, 0-15 parts of silicate mineral particles, 1-4 parts of magnesite clinker particles, 1-4 parts of magnesite clinker fine powder, 10-20 parts of corundum fine powder, 4-12 parts of SiC fine powder, 7-15 parts of crystalline flake graphite, 0-3 parts of an antioxidant and 2-6 parts of a binding agent. According to the preparation method, the particle size and content of magnesite clinker particles and powder in the refractory brick are set, so that on the one hand, the refractory brick is enabled to maintain a certain high temperature line expansion ratio and residual expansion ratio, and steamed bun-shaped melting loss at working lining brick joints during the using process is reduced, on the other hand, the medium-high temperature strength, properties of corrosion resistance to molten iron and molten slag and high-temperature oxidation resistance property of the refractory brick can be improved.

Description

technical field [0001] The invention relates to the technical field of refractory materials, in particular to an Al 2 o 3 -MgO-SiC-C brick and its preparation method. Background technique [0002] With the continuous development of the iron and steel metallurgical industry, the molten iron ladle is not only used as a container for molten iron in the ironmaking system, but also needs to undertake the tasks of removing S and P. At present, desulfurization of molten iron is the most important treatment method of molten iron in domestic and foreign steelmaking plants. Desulphurization methods generally include spray desulphurization method and KR stirring method. During the desulphurization process, a large amount of slagging agents such as passivated magnesium powder, lime, fluorite, etc. will be introduced, which will wrap the wall of the molten iron, especially the slag line. Erosion is more serious. [0003] Al 2 o 3 -SiC-C brick has excellent mechanical properties at ...

AI Technical Summary

Problems solved by technology

[0005] (1) The working layer of the cladding wall is prone to "steamed bread" melting loss: traditional Al 2 o 3 -SiC-C brick high temperature thermal expansion rate and residual expansion rate are small

The molten iron ladle has a long service life, and it is difficult to heal the brick joints under the condition of long-term alternating use of cold and hot, which becomes the channel for the erosion and penetration of molten iron and slag, resulting in "steamed bun-like" melting loss, and sometimes even the phenomenon of permanent iron infiltration [ 1 Duan Xiaodong. Factors and Measures Affecting Lining Life of Hot Metal Tanks. Sichuan Metallurgy, 2003,25(2):30-32]

[0006] (2) Poor ability to resist molten iron and slag melting loss: During the desulfurization process of molten iron, a large amount of alkaline slagging agent will be introduced into the molten iron

However, the addition of a large amount of the above-mentioned silicate minerals will significantly reduce the resistance to molten iron and slag melting loss of the material

[0007] (3) In order to improve the medium and high temperature oxidation resistance of the material, a large amount of antioxidants such as simple Si powder, B 4 C powder, etc., on the one hand, the cost is high, and on the other hand, it is not conducive to the corrosion resistance of the material [4 Hou Jin, Liu Fang, Zhao Liang. Al 2 o 3 -Research and application of oxidation resistance of SiC-C bricks. 2004,30(5):36-38]

Traditional Al 2 o 3 - There are a series of problems in the use of SiC-C bricks, which cannot meet the requirements of high service life of the ladle

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