Alumina refractory bricks

　　Alumina brick is a type of refractory brick that is made from high-grade alumina (AI2O3) and other raw materials. It has high refractoriness, excellent thermal stability, and good resistance to chemical erosion and mechanical wear.

　　Alumina bricks can be divided into two types based on their alumina content: high-alumina brick and low-alumina brick. High-alumina bricks typically have an alumina content greater than 48%, while low-alumina bricks have an alumina content between 30% and 48%.

　　Alumina bricks are widely used in various high-temperature industrial applications, such as in steel-making furnaces, glass tanks, cement kilns, and petrochemical reactors. They are also used in incinerators and power plants as insulation or protective lining materials.

　　The properties of alumina bricks can vary depending on the manufacturing process, raw materials used, and the specific application requirements. Some common properties of alumina bricks include high refractoriness, excellent thermal shock resistance, good chemical resistance, and high mechanical strength.

　　The main properties of alumina bricks include:

　　1.High temperature resistance

　　Alumina bricks can withstand temperatures of up to 1800°C, making them ideal for use in furnaces, kilns, and incinerators.

　　2.Good thermal shock resistance

　　Alumina bricks have excellent thermal stability and can resist rapid temperature changes without cracking or spalling.

　　3.High mechanical strength

　　Alumina bricks have high compressive strength, which makes them suitable for use in high-stress applications.

　　4.Excellent chemical stability

　　Alumina bricks are highly resistant to acids, bases, and other corrosive chemicals, making them suitable for use in various chemical processes.

　　5.Low porosity

　　Alumina bricks have low porosity, which provides good insulation and helps to reduce heat loss.

　　6.Abrasion resistance

　　Alumina bricks have good wear resistance, making them suitable for use in applications where the brick is exposed to abrasive materials.

　　7.Good electrical insulation

　　Alumina bricks are good electrical insulators, making them useful in applications where electrical insulation is required.

　　1. Lining of high-temperature kilns and furnaces:

       Alumina brick can withstand temperatures up to 1800°C and is commonly used in the lining of high-temperature kilns, furnaces, and other industrial equipment where high thermal shock resistance and abrasion resistance are required.

　　2. Blast furnace lining:

　　Alumina brick is highly resistant to slag attack and can withstand the harsh conditions in blast furnaces. It is commonly used in the lining of iron-making blast furnaces, where it provides excellent performance in resisting thermal shock, corrosion, and erosion.

　　3. Petrochemical industry:

　　Alumina brick is widely used in the petrochemical industry, where its corrosion resistance and high-temperature stability make it an ideal material for lining reactors, distillation towers, and other high-temperature equipment.

　　4. Power generation industry:

　　Alumina brick is also used in the power generation industry, particularly in the lining of coal-fired boilers and gasifiers. The high thermal conductivity and excellent thermal shock resistance of alumina brick allow it to withstand the extreme temperature fluctuations and corrosive gases generated during combustion.

　　5. Other applications:

　　Alumina brick can also be used in various other applications, such as in the lining of aluminum smelting cells, calciners, cement kilns, and glass furnaces.

　　(一)Density conductivity of alumina brick

　　The density and thermal conductivity of alumina brick are closely related, as the density of the brick affects its ability to conduct heat. Generally, higher-density alumina bricks have a lower thermal conductivity than lower-density bricks, due to their greater resistance to heat transfer.

　　The density of alumina brick can vary depending on several factors, such as the purity of the alumina, the manufacturing process used, and the size and shape of the bricks. Typical densities for alumina brick range from about 2.8 to 3.5 g/cm^3 (grams per cubic centimeter), although some specialty bricks may have different densities.

　　The thermal conductivity of alumina brick can also vary depending on these factors, as well as the temperature at which the brick is operating. Generally, high-purity dense alumina bricks have a lower thermal conductivity than lower-purity or less-dense bricks, with typical values ranging from about 1 to 4 W/m-K (watts per meter-kelvin) at room temperature.

　　Alumina brick is commonly used in high-temperature applications where low heat transfer is desirable, such as furnace linings, kiln linings, and thermal insulation. Its density and thermal conductivity properties make it well-suited for these applications, as it can help to reduce heat loss and improve energy efficiency.

　　(二)Thermal conductivity of alumina brick

　　The thermal conductivity of alumina bricks depends on several factors, such as the purity and density of the alumina, the manufacturing process used, and the operating temperature. Generally, high-purity dense alumina bricks have a lower thermal conductivity than lower purity or less dense bricks.

　　The thermal conductivity of alumina bricks can range from about 1 to 4 W/m-K (watts per meter-kelvin) at room temperature, depending on their composition and other factors. At high temperatures, the thermal conductivity of alumina bricks tends to increase due to the greater movement of electrons and phonons within the material.