Al2O3-MgO refractory castable and preparation method thereof

Abstract

The invention discloses an Al2O3-MgO refractory castable and a preparation method thereof. Specifically, the refractory castable comprises: 55-75wt% of corundum grains, 10-25wt% of corundum fine powder, 5-25wt% of light burned spinel fine powder, 0.8-5wt% of magnesia fine powder, 3-6wt% of calcium aluminate cement, 1-4wt% of alpha-Al2O3 micropowder, 0.2-2wt% of silicon oxide micropowder, additional water accounting for 4.5-6wt% of the refractory castable and 0.1-1wt% of a water reducer. The preparation method includes: stirring the raw materials of the refractory castable evenly, conducting pouring vibration molding, letting the molded refractory castable green body dry naturally for 24h, and then conducting drying at 110DEG C for 12-36h, thus obtaining the Al2O3-MgO refractory castable. The refractory castable has the characteristics of controllable microstructure and controllable spinel crystal structure parameters, and the high temperature volume stability and slag resistance of refractory castable are effectively improved. The preparation method has the advantages of simple process, energy saving and environmental protection, and low cost.

Description

technical field [0001] The present invention relates to a refractory material, in particular to an Al 2 o 3 - MgO refractory castable and preparation method thereof. Background technique [0002] Al 2 o 3 -MgO-based refractory castable has excellent performance and is easy to build, and has been widely used in the cladding wall and bottom of the ladle as the lining material. Refractory materials are generally composed of aggregate and matrix, and the matrix part has an important influence on the properties of refractory materials, especially the slag resistance performance, which is related to Al 2 o 3 -Introducing spinel into MgO-based refractory castable matrix is ​​one of the important methods to improve its performance. [0003] At present, Al 2 o 3 There are three main methods for introducing spinel into the matrix of -MgO refractory castables. The first is to ask Al 2 o 3 -Introduce MgO raw materials into the MgO refractory castable matrix to form spinel in ...

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Problems solved by technology

[0004] However, the above methods have certain defects: (1) When the first method is adopted, due to the large volume expansion when the spinel is formed in situ, micro-cracks are generated inside the castable, resulting in a decrease in the slag resistance; ( 2) When using the second and third methods, it is necessary to introduce pre-synthesized spinel, but at present, pre-synthesized spinel is fused spinel formed by melting above 2000°C or fired at high temperature above 1700°C Sintered spinel, in the process of preparing these pre-synthesized spinel raw materials, will waste a lot of energy, and the production cost is high; (3) Usually, the bulk density of fused spinel or sintered spinel is relatively high, and in refractory materials It is difficult to disperse uniformly. Although it can increase the degree of uniform dispersion after fine grinding, too small particle size will lead to a decrease in corrosion resistance, so it cannot improve the Al alloy to the greatest extent. 2 o 3 -Slag resistance performance of MgO-based refractory castables