Precautions for The Use of Clay Brick
Precautions for the use of clay brick:
(1) The performance of clay brick products produced by different molding methods is different from that of clay bricks. It can be formed by hand molding, beating molding, extruder molding, mud casting molding and press molding. Even if the chemical composition and the raw material type are the same, the clay bricks may have different properties due to different molding methods.
In the clay bricks produced by various molding methods other than the high-pressure molding method, the content of the binder is relatively large, and thus the firing temperature cannot be too high. The brick has a low softening temperature, a large reburning shrinkage, and a high porosity. The structure of the clay brick produced by the mud casting method and the high pressure molding method is relatively uniform. However, the clay bricks produced by other molding methods have a relatively uniform structure, and there are problems such as layered structure, directional cracking and internal cracks.
(2) Aggregates and conjugates generally combine with refractory aggregates and conjugates to have different erosion resistance. The aggregate is more resistant to erosion than the combination. When the difference in corrosion resistance between the two is large, the conjugate is first eroded, causing damage to the entire refractory material. However, in order to obtain clay bricks having a low porosity, a small amount of quartz and R2O are often added to the combination. Thus the mechanical strength of the clay bricks increases. However, this also causes a decrease in the erosion resistance of the combination.
According to this feature, different clay bricks can be selected in different parts of the pool furnace due to different erosion conditions. The lower furnace brick and the lower lattice brick of the regenerator are less eroded by the dust and volatile matter of the batch material, the temperature is lower, and the load is heavy. The brick requires high mechanical strength. Therefore, the conjugate in the brick may contain an appropriate amount of SiO2, Fe2O3, and R2O, but the clay brick used for the high temperature portion mainly requires high refractoriness, and the conjugate has less impurities.
(3) The erosion of clay bricks is mainly affected by the following two aspects. The first is the type of etchant and the rate of chemical reaction; the second is the concentration of the reaction product. Also with the structure of clay bricks and temperature, time, physical and chemical erosion conditions.