Is it necessary to add burnt stones to low porosity clay bricks?
Low porosity clay bricks must be added with burnt gemstones to reduce the pores. The level of pores is related to the amount of burnt gemstones added. The greater the amount added, the lower the porosity, and the service life will be more than 2 times longer than that of ordinary clay bricks.
1. Characteristics of low porosity clay bricks
Charcoal is a kind of refractory raw material. It is a kind of hard refractory clay. The main mineral is kaolin. Charcoal has stable composition, uniform texture, dense structure and shell-shaped cross-section. It also has the characteristics of stable volume, high strength and low water absorption. By adding a certain proportion of burnt gemstones to the raw materials of clay bricks, low porosity clay bricks can be produced. Low-pore clay bricks have the characteristics of strong density, low pores and resistance to acid erosion. strong ability. Its characteristic is that it is not oxidized and deformed at high temperatures. By adding a certain proportion of charred gemstones, and then through high-pressure molding and high-temperature firing, the strength of low-porosity clay bricks increases, the low porosity decreases, and the water absorption rate is lower.
2. Burnt gemstones are graded
Burnt gemstones are divided into grades, and the properties of different grades are also different. They are also divided into large pieces and small pieces. There are many impurities in small pieces. After being added to the brick making process, black spots and caves will appear. According to the requirements of different pores, some manufacturers will strictly control the quality when purchasing raw materials, and will select and weather some impurities. Of course, the appearance, pores and performance of low porosity clay bricks produced from different levels of burnt gemstones will be different.
3.Suitable temperature for mullite castable
After adding charred gems to low-porosity clay bricks, the properties of charred gemstones will be inside the brick to prevent and inhibit the occurrence of micro-pores and fractures. When a large number of micropores are generated in the brick, the length of internal cracks in the clay brick under thermal shock will become shorter, but the degree to which the shortened cracks will intersect with each other to form a network will increase. Therefore, adding burnt gemstones to clay bricks can effectively improve the thermal shock stability of clay bricks and improve the spalling resistance of clay bricks.
4. Burnt gems must be added to adjust
When the lining atmosphere of industrial kilns is acidic gas, it is most suitable to use low porosity clay bricks, because ordinary clay bricks have the disadvantages of peeling off, high porosity, and large water absorption, especially after high temperature, the generation of water vapor makes Clay bricks are spalling. The addition of burnt gemstone clay bricks increases the amount of liquid phase in the body matrix, and the burnt gemstone can promote sintering and reduce the pores of the bricks.
Therefore, the pore height of low porosity clay bricks must be adjusted by adding burnt stones.
