The size of the large pores of the Micropore Corundum Brick is 20-8o μ m, the size of the medium pores is about negative 0.85 μ m, and the r-inch force of the small pores is 0.003-0.006 μ M. The pore curve measured by mercury porometer method is shown in Figure 7. Pore size distribution depends on CaO / SiOa ratio. If the CaO / SK ^ CL of the proportioning is in the area of cms-mf-ma-m, especially in the area of 1325, there is liquid phase in the area, but there is no significant effect on the sintering process of the castable, and small pores still exist. When CaO / SiOa > 2, the bond is in the ca-ca-f (C4 AF) - mf-m region. The minimum value of the contact angle of periclase is consistent with the liquid phase of the component. In column 14001, although the number of liquid phase is smaller than that in the case of CaO / SiC ^ C ^, it has reached the minimum porosity and the minimum pore size. The distribution of pores depends on the particle composition of the ingredients. When fine particles and microporous corundum bricks exist at the same time, the complex component structure with uneven composition is formed, and the local sintering process that causes different shrinkage can also be observed. Because the total shrinkage is not in proportion, some pores with larger pore size than that before sintering are produced. These pores shrink very slowly, and most of them remain after 20001 sintering. However, the reason of pore growth is not only due to the proportion of particles, but also due to the agglomeration of particles, because in the case of uniform particle proportioning, the phenomenon of pore growth occurs during sintering and use.
Under the microscope, the structure of magnesium products is generally fragmentary, which is characterized by complex ancestry. Sintered Micropore Corundum Brick particles are composed of 0. (u-0.1mm) periclase polycrystal particles, which are orange yellow and grayish brown, depending on whether there is a solid solution of magnesite & with the increase of Duocheng temperature (or service temperature), the periclase particles increase, and they are regular hexagonal. When heated for a long time at a higher temperature, the particles Along the cleavage crack, the particles are broken into rectangular blocks. In the pores between the periclase particles, the silver around the particles is inlaid with silicate phase film. The silicate phase is Ca Mg microalliorite [&].
The structure of MgO ^ 8% - > of MgO microporous corundum brick is composed of single periclase particles, in which the dislocation of impurity deposition is found. In addition to castables, micro calcium and magnesium are also found in microporous corundum bricks.
