Clay refractory brick firing the five steps

Clay refractory bricks are some raw materials produced by a certain production process, mainly after five steps.

The first step, the preparation of clinker clinker: clay cooked 枓 is a barren raw material, it plays a role in the refractory bricks. Clay clinker is made of hard stickers in the rotary kiln: or soft clay pre-made into the ball, the material block, and then calcined.

The second step, combined with the choice of clay and other binders: the basic requirements for the combination of clay, should be high plasticity, low sinterability, and has good fire resistance. According to the characteristics of China's raw materials and process, usually using semi-soft clay and soft paste on the mixed, semi-soft clay-based compound ingredients.

The third step, the preparation of mud: clinker and clay with the ratio of refractory bricks should be the quality requirements, the size of the shape and the body of the molding method of many factors. For some large refractory brick products, in order to reduce the accumulation of sintering shrinkage, to maintain good shape, the appropriate increase in the amount of clinker ingredients. Clay refractory brick particles, the general coarse particles, the particles less, so not only to ensure the density and strength of refractory bricks, but also improve the thermal shock stability of refractory bricks. At the same time, should also be based on the size of refractory bricks and surface quality requirements to adjust and modify the particle size. Material mixing, the first is to join the clinker coarse particles, plus raw material mud, and finally add clinker powder and combined with clay.

The fourth step, forming and drying: clay refractory bricks generally use semi-dry molding method to suppress the molding, so the blank water is low, such as firing kiln with a dry section, you can not pre-dry and directly into the kiln firing.

The fifth step, firing: clay refractory bricks in the firing process, the brick in the high temperature and the appropriate atmosphere under a series of physical - chemical changes and sintering. Which combined with the heating characteristics of clay directly affect the product firing system to determine. The higher the content of Al2O3 in the clay, the higher the content of the impurities, the more severe the reaction, the volume shrinkage and the uneven heating, resulting in the greater the internal stress, the greater the amount of impurities in the clay. , Easily lead to brick in the firing stage cracking.