Refractory bricks are referred to as fire bricks. They are mainly refractory materials made by burning refractory clay or other refractory raw materials. They are light yellow or brown. They are mainly used to build smelting furnaces and can withstand high temperatures of 1,580℃-1,770℃. They are also called fire bricks. Refractory materials with certain shapes and sizes. Correct and reasonable use of fire bricks can extend the service life of refractory firebricks.
1. Choose suitable refractory fire bricks
Different working conditions have different requirements for firebricks, so choosing suitable refractories bricks is the key to ensuring their performance.
High temperature environment: When used in a high temperature environment, fire bricks of different materials need to be selected according to specific temperature requirements. For example, silica bricks are suitable for acidic high temperature environments, while magnesium bricks are suitable for alkaline high temperature environments.
Chemical erosion: If there is an acidic or alkaline medium in the equipment, refractory bricks with corrosion resistance should be selected to avoid damage to the brick body due to chemical erosion.
Mechanical load: For heavy equipment, high-strength firebricks, such as high-alumina bricks or corundum bricks, are required to cope with mechanical stress and impact.
2. Correct construction
The construction quality of firebricks is directly related to their use effect, so the following requirements must be strictly followed during the construction process:
Masonry method: According to the design requirements, appropriate masonry methods, such as straight masonry or oblique masonry, are adopted to ensure that the firebricks fit tightly together.
Expansion joint treatment: Appropriate expansion joints must be reserved during construction to adapt to the thermal expansion characteristics of refractory bricks and prevent cracking of bricks due to thermal stress.
Use of binder: Select refractory slurry that matches the refractory fire bricks and evenly apply it to the contact surface of the bricks to avoid gaps or falling off.
3. Reasonable heating and furnace baking
After the fire bricks are put into use for the first time or re-laid, scientific furnace heating is required:
Heating curve: According to the design requirements, the temperature is gradually increased in stages. The initial low temperature stage is the key to completely remove the residual moisture inside the firebricks.
Avoid sudden temperature rise: A sudden increase in temperature will produce greater thermal stress, which will cause the fire bricks to crack or even peel off.
4. Prevent rapid cooling
Refractory bricks should avoid sudden cooling during high-temperature use. Sudden cooling will cause thermal stress inside the refractory firebricks, resulting in cracks or deformation. Therefore, when the furnace is shut down or the equipment is overhauled, slow cooling measures should be taken to ensure that the fire bricks can be gradually cooled.
5. Avoid mechanical shock and wear
Refractory firebricks are more brittle in high-temperature environments and are easily affected by mechanical shock and wear. To this end:
Install protective devices: For areas that are susceptible to impact, such as furnace mouths and furnace walls, protective layers can be added to reduce wear.
Handle with care: In daily maintenance, hard objects should be avoided as much as possible from hitting refractories bricks, especially bricks in high-temperature operations.
6. Control chemical erosion
During use, minimize the contact between refractory bricks and corrosive substances:
Reduce slag erosion: In furnace operation, control the composition and flow of slag to reduce erosion of refractories bricks.
Protective coating: In a highly corrosive environment, a special protective coating can be added to the surface of the refractory fire bricks to improve their corrosion resistance.
VII. Regular inspection and maintenance
The service life of refractory firebricks is closely related to daily inspections. Regularly check whether the bricks have cracks, falling off, deformation, etc. Once a problem is found, the damaged bricks should be repaired or replaced in time to prevent the problem from expanding.
