If it is made to refractory bricks,dry in the air naturally for 10 days, then put into the drying furnace, which is certainly better than the brick is put to the furnace directly, this is not easy to crack. After all, the moisture of brick will run in the air. See the semi-finished products (not crack is really no crack), but after drying, it has cracks, this is must because moisture runs quickly in a short time. If it cracks after high temperature heat treatment, the reason is very complicated, such as after high temperature burning, temperature decreases too fast, resulting in a large temperature change, then it cracks. Or in the process of high temperature heat treatment, the internal reaction is intense, and generate some volume expanding materials, resulting in cracks and so on. Mullite Petrochemical reaction, spinel reaction and so on, the reactions of a lot of materials are the volume expansion
The relative density is high, and high temperature heat treatment and increase the strength of qualitative brick, for 10 days, then only the shorter time for heating and drying and dehydrating, you can smash a brick if it's a long time! There will be a stress loose phenomenon making bricks now, the internal density of these crack bricks are not the same, in addition to the effective drying, dehydrating and heating treatment, the time distance is small, basic bricks and finished bricks adopt line production, when drying, the water is also evaporated at the same time, the central density should be high ! The reason is very simple, the greater extrusion force the brick bears in the molding, the closer to the edge, the smaller density is, the better to keep forming, the shorter residence time, the higher the rate of finished product is, which belongs to the natural drying, this phenomenon is more obvious
This is inorganic nonmetallic material
