Corundum bricks are a type of high - performance refractory material that has been widely used in various industrial fields. As a supplier of corundum bricks, I am very familiar with their main properties, which I will elaborate on in this blog.
1. High Refractoriness
One of the most prominent properties of corundum bricks is their high refractoriness. Corundum, which is mainly composed of aluminum oxide (Al₂O₃), has a melting point of about 2050 °C. This high melting point allows corundum bricks to withstand extremely high temperatures without melting or deforming easily.
In industrial applications such as steelmaking, non - ferrous metal smelting, and glass manufacturing, furnaces often operate at temperatures well above 1000 °C. Corundum bricks can be used as lining materials in these high - temperature furnaces. For example, in an electric arc furnace for steelmaking, the temperature inside the furnace can reach up to 1600 - 1700 °C. Corundum bricks can maintain their structural integrity under such high - temperature conditions, providing a stable working environment for the smelting process.
2. Excellent Chemical Stability
Corundum bricks exhibit excellent chemical stability. They are resistant to the corrosion of many chemical substances, including acids, alkalis, and molten metals.
In acid - resistant applications, corundum bricks can resist the attack of sulfuric acid, hydrochloric acid, and other strong acids to a certain extent. This makes them suitable for use in chemical plants where acidic substances are processed or stored. For instance, in the production of phosphate fertilizers, where phosphoric acid is involved, corundum bricks can be used to line the reaction vessels to prevent corrosion.
In alkaline environments, corundum bricks also show good resistance. In some industrial processes such as the production of soda ash, where sodium hydroxide or other alkaline substances are present, corundum bricks can maintain their performance. Moreover, when in contact with molten metals like iron, copper, and aluminum, corundum bricks do not react easily with them, ensuring the purity of the molten metals and the long - term use of the refractory lining.
3. High Mechanical Strength
Corundum bricks possess high mechanical strength, which enables them to withstand mechanical stress and pressure during use. This strength is crucial in industrial furnaces where the bricks may be subjected to the weight of the charge, the impact of moving materials, and the vibration during the operation of the equipment.
In a blast furnace, for example, the corundum bricks in the hearth and bosh areas need to support the weight of the iron ore, coke, and other materials. The high mechanical strength of corundum bricks ensures that they do not break or crack under this heavy load. In addition, during the charging and discharging processes in the furnace, the bricks may be hit by the materials, and their high strength allows them to resist such impacts and maintain the integrity of the furnace lining.
4. Low Thermal Conductivity
Another important property of corundum bricks is their relatively low thermal conductivity. Low thermal conductivity means that they can effectively reduce heat loss from the furnace, improving the energy efficiency of the industrial process.
In a glass melting furnace, heat conservation is of great importance. By using corundum bricks with low thermal conductivity as the lining material, less heat will be transferred through the furnace wall to the outside environment. This not only saves energy but also helps to maintain a stable temperature inside the furnace, which is beneficial for the quality of the glass production.
5. Good Abrasion Resistance
Corundum bricks have good abrasion resistance. In industrial applications where materials are flowing or rubbing against the refractory lining, such as in the cyclone separators of cement kilns or the coal - fired boilers, the abrasion resistance of corundum bricks is highly valued.
In a cement kiln, the raw materials and clinker are continuously moving and flowing inside the kiln. The corundum bricks used in the kiln lining can resist the abrasion caused by the movement of these materials, ensuring the long - term stability of the lining and reducing the frequency of maintenance and replacement.
6. Low Porosity
Corundum bricks typically have low porosity. Low porosity is beneficial in several ways. Firstly, it reduces the penetration of corrosive substances into the bricks. Since there are fewer pores for the corrosive agents to enter, the internal structure of the bricks is better protected, and the corrosion resistance is enhanced.
Secondly, low - porosity corundum bricks have better thermal insulation performance. Pores can act as channels for heat transfer, so reducing the porosity can decrease the heat conduction through the bricks. In addition, low - porosity bricks also have higher mechanical strength because there are fewer weak points in the structure.
Different Types of Corundum Bricks and Their Specific Properties
There are different types of corundum bricks, each with its own specific properties and applications. One of the important types is the AZS Zircon Corundum Bricks.
AZS zircon corundum bricks are made by adding zirconium oxide (ZrO₂) to the corundum matrix. The addition of zirconium oxide enhances the corrosion resistance of the bricks, especially in glass - melting furnaces. In glass production, the molten glass contains various oxides and fluxes, which can be highly corrosive to the refractory lining. AZS zircon corundum bricks can resist the corrosion of the molten glass, improving the service life of the furnace lining and ensuring the quality of the glass.
Applications Based on Properties
Based on the above - mentioned properties, corundum bricks have a wide range of applications in different industries:
- Metallurgical Industry: In steelmaking, ironmaking, and non - ferrous metal smelting, corundum bricks are used in furnaces, ladles, and tundishes. Their high refractoriness, chemical stability, and mechanical strength make them ideal for withstanding the harsh conditions in these processes.
- Glass Industry: As mentioned earlier, in glass melting furnaces, corundum bricks, especially AZS zircon corundum bricks, are used to line the melting tanks, forehearths, and other parts. Their corrosion resistance to molten glass and low thermal conductivity are crucial for glass production.
- Cement Industry: In cement kilns, corundum bricks are used in the high - temperature zones such as the burning zone and the transition zone. Their abrasion resistance and high refractoriness ensure the normal operation of the kiln.
- Chemical Industry: In chemical plants, corundum bricks are used in reaction vessels, storage tanks, and other equipment where they need to resist the corrosion of various chemical substances.
Conclusion
In conclusion, corundum bricks have a series of excellent properties, including high refractoriness, excellent chemical stability, high mechanical strength, low thermal conductivity, good abrasion resistance, and low porosity. These properties make them indispensable in many industrial fields. Whether it is the high - temperature environment in the metallurgical industry, the corrosive conditions in the chemical industry, or the wear - prone situations in the cement industry, corundum bricks can play an important role.
If you are looking for high - quality corundum bricks for your industrial applications, we are here to provide you with the best products. Our corundum bricks are manufactured with strict quality control to ensure that they meet your specific requirements. We welcome you to contact us for procurement and further discussions. We are committed to providing you with professional solutions and excellent service.
References
- "Refractories Handbook" by R. C. Bachu.
- "Industrial Furnaces and Heat - Processing Technology" by G. E. Totten.
- Technical papers on corundum bricks published in international refractory journals.
