The materials used in lime kilns depend primarily on their kiln type, operating temperature, operating environment, and the characteristics of the materials being processed.
Refractory Materials
High-alumina bricks: Widely used in preheating zones, transition zones, and other medium-to-high temperature areas. Al₂O₃ content is typically ≥45%, exhibiting good erosion resistance and high-temperature stability.
Magnesium-alumina spinel bricks: Commonly used in the firing zones of rotary kilns and other high-temperature, highly corrosive areas, effectively resisting CaO erosion and thermal shock.
High-purity mullite bricks: Suitable for high-temperature zones, possessing excellent thermal shock stability and load softening temperature.
Clay bricks/High-density clay bricks: Primarily used in low-temperature zones or as insulation layers, with lower cost.
Special shaped bricks: New patented materials used to reduce heat loss and improve deformation resistance, suitable for modern energy-saving lime kilns.
Phosphate-bonded high-alumina bricks: Suitable for vertical kilns, with good thermal shock resistance, suitable for areas with large temperature fluctuations.
Silicon carbide or silicon nitride composite materials: Used in highly corrosive and abrasive environments, significantly extending service life.
Kiln Structure Materials
Inner Lining: Constructed from the aforementioned refractory bricks, directly in contact with high-temperature materials and gases.
Insulation Layer: Typically uses lightweight insulating bricks or ceramic fiber cotton to reduce heat loss.
Steel Shell Structure: Serves as external support, especially for the inner sleeve in sleeve kilns.
Sealing and Corrosion Protection Materials: Such as zinc-rich primer + ethyl silicate ceramic topcoat, used for corrosion protection of the steel structure.
