Fused zirconia corundum brick belongs to Al2O3-ZrO2-SiO2 system (abbreviated as AZS brick). According to the content of ZrO2, it is divided into three grades: 33%, 36%, and 41%. The phase composition volume percentages are listed in Table 4-33. The corresponding national brands are AZS-33 (including ZrO2: 33%); ER1681 (France), Бakop-33 (Russia), ZB1681 (Japan). AZS-36 (containing ZrO2: 36%); ER1691 (France), ZB61691 (Japan), S-4 (United States). AZS-41 (containing ZrO2: 4.1%); ER1711 (France), ZB1711 (Japan).
The fused zirconia corundum brick has better resistance to glass erosion than the fused mullite brick, and the main reason is as follows.
The main crystal phase in the zirconia corundum brick is the coexistence of corundum and oblique zircon, and both of these crystal phases have good corrosion resistance.
In the zirconium corundum brick, the glass phase is filled between the above crystal phases. This glass phase is attacked by a high-temperature glass liquid to produce a highly viscous albite glass. Since a certain amount of ZrO2 is melted and the viscosity is larger, this layer High-viscosity glass stays on the brick surface and does not spread easily, thus protecting the brick body. The corrosion resistance of fused zirconia corundum bricks increases with the increase of ZrO2 content. Because the melting temperature of ZrO2 is as high as about 2700, and it has a high ability to resist media such as acid, alkali and glass.
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