What is the impact of the refractory brick's refractoriness?
Release time：
2018-08-07 16:19
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1. The variety and nature of the main crystalline phase and the intertwined phase between the main crystalline phase or the main crystalline phase and the secondary crystalline phase.
2. The nature of the matrix and the ratio of the matrix to the main crystalline phase or the same main crystalline phase and the secondary crystalline phase and the diffuse form.
3. The compactness of refractory bricks and the condition of stomata. When refractory refractory bricks are composed of single-phase polycrystals, the refractory bricks have the refractoriness and the melting point of the crystal phase. For example, high-purity refractory bricks composed of high-melting crystals. The refractoriness of the high-purity sintered corundum bricks can be as high as 1870 °C at the beginning.
When the high melting point crystals in the refractory bricks cross each other or become intertwined into a firm network structure, the refractoriness is definitely higher. Conversely, when the high melting point crystal phase is lonely, the refractory bricks have a relatively low refractoriness. For example, silicon The composition of the bricks is mainly composed of squamous crystals and smectite crystals. The squamous crystals become a network structure in which the double-crystals are intertwined in the bricks. Therefore, the refractoriness is usually high, and the softening temperature at the beginning is more than 1650 ° C. Up to 1680 ° C or higher, higher than the melting point of the squamous crystal (1670 ° C) and ordinary magnesium brick, in which the melting point of the main crystalline phase of the magnesite is as high as 2800 ° C, but because the main crystal phase is alone, the load softening starts at only 1550 °C up and down.
When the refractory brick has a matrix in addition to the high melting point crystal phase, whether the matrix can easily become a melt under the tropics, whether the viscosity of the melt can easily decrease with temperature, and the number of the matrix and the distribution have a certain degree of refractoriness. Significant effects. For example, the main crystal phases of clay refractory bricks and high-alumina refractory bricks with lower Al2O3 are mullite, so they contain more SiO2-rich vitreous matrix, and mullite crystals are distributed here. However, the substrate can be softened at the beginning under 1000 ° C, so the temperature at the beginning of softening deformation is low, and depending on the matrix content, the mullite and the matrix content ratio can be reduced.
In addition, in view of the fact that the viscosity of such a matrix decreases slowly with temperature, the deformation temperature boundary is wider. For example, the main crystal phase of the magnesia grain of the ordinary magnesia brick is surrounded by the matrix, and the matrix is made of fusible. The silicate crystal composition, the refractory brick's refractoriness is controlled by the matrix, so it is lower. After the matrix is melted, its viscosity is very low, so the sample is easily split easily. Another example is that the silica brick has a high load softening temperature. In addition to the skeleton composed of squamous crystals, it is also related to the matrix of the high-viscosity glass phase. The refractory brick has a high porosity and can lower the starting point of the load softening.