- Time:May 12, 2023
Mullite refractory brick is a high-performance refractory material. It can be divided into different types according to different manufacturing processes and components. The following will introduce the common types of mullite refractory bricks.
1. Lightweight mullite refractory brick
Lightweight mullite refractory bricks have low density, light weight, good thermal insulation performance, and are widely used in internal isolation and thermal insulation of various high-temperature kilns.
2. Ordinary mullite refractory brick
Ordinary mullite refractory bricks are processed by mullite powder and other additives through multiple processes such as mixing, molding, drying, and sintering. They have certain compressive strength and fire resistance, and are suitable for various industrial kiln buildings. Lining, ground and other parts.
3. High alumina mullite refractory brick
High-alumina mullite refractory bricks are made of a mixture of alumina and mullite. They have excellent high-temperature corrosion resistance and are widely used as linings and isolation layers in large-scale high-temperature kilns such as metallurgy and chemical industry.
4. Corundum mullite refractory brick
Corundum mullite refractory bricks are made of corundum and mullite through a special process. They have extremely high refractory temperature and corrosion resistance, and are suitable for various special kilns in harsh environments such as high temperature and high pressure.
5. Low creep mullite brick
Low-creep mullite bricks are made of synthetic mullite clinker and super-grade high-alumina bauxite clinker, and some high-purity quartz and additives are added to produce low-creep mullite bricks.
Forming is carried out on a 300t friction brick press. The bulk density of the green body should be controlled above 2.70g/cm3. The green body is dried at 50~110°C for 16 hours. After drying, the residual moisture of the green body should be less than 0.5%. The highest firing temperature of the product is 1600°C, and the heat preservation time is 16h. The physical indicators of the product are as follows: apparent porosity 19~21%; bulk density 2.55~2.60g/cm3; compressive strength 69~116MPa; 1450°C, 50h pressure creep rate 0.12%.
6. Sintered mullite brick
The sintering temperature of sintered mullite bricks is usually above 1600°C. Such a high sintering temperature makes sintered mullite bricks difficult to mass-produce. Utilizing the activity of active SiO2, adding an appropriate amount of active SiO2 into the ingredients can make the sintered mullite bricks sintered at 1550 °C.
The physical indicators of this sintered mullite brick are as follows: apparent porosity 20.88%, bulk density 2.61g/cm³, normal temperature compressive strength 84.4MPa, 1550°C, 50h high temperature creep rate 0.796%. The above are several common types of mullite refractory bricks. According to specific usage scenarios and requirements, mullite refractory bricks of different models and specifications can be selected.
