Mullite insulating bricks are manufactured using carefully selected high-purity raw materials and a unique foaming molding and high-temperature sintering process. Their exceptional performance stems from the inherent low thermal expansion coefficient, high melting point, and chemical stability of the mullite phase, combined with a meticulously designed closed-cell pore structure:
Extremely high operating temperature and stability: The pure mullite phase exhibits high refractoriness and volume stability at elevated temperatures, with minimal linear change upon re-firing. The structure remains free from shrinkage or deformation during prolonged use.
Superior thermal insulation: Uniformly distributed nano-micron closed pores effectively block thermal conduction and convection, achieving a thermal conductivity far lower than traditional insulating materials.
Exceptional thermal shock resistance: The inherent low thermal expansion coefficient of mullite enables the bricks to withstand rapid thermal cycling without cracking.
Good chemical corrosion resistance: Excellent tolerance to acidic and weakly alkaline environments, with stable performance in reducing atmospheres.
Low heat capacity and high purity: Minimal heat storage capacity delivers significant energy savings; low iron and alkali metal impurity content makes it suitable for industrial environments requiring high cleanliness.
Key Technical Specifications:
- Al₂O₃ content: 60% - 75% (mullite phase dominant)
- Bulk density: 0.6 g/cm³ - 1.2 g/cm³ (series-based)
- Compressive strength at room temperature: ≥ 1.8 MPa - 8.0 MPa
- Thermal Conductivity (Average Temperature 1000°C): 0.25 W/(m·K) - 0.40 W/(m·K) (Varies with density)
- Re-firing Linear Change (1500°C × 12h): ≤ 1.0%
- Maximum Service Temperature: 1450°C - 1650°C (Graded)
