Fire bricks are the core lining material of kiln production lines. Their function is to withstand the high temperatures of the kiln, resist material/flue gas erosion, and prevent heat loss, directly determining the kiln’s service life, thermal efficiency, and production stability.
Clay Bricks:
Composition: Al₂O₃ content 30%–48%, mainly made from refractory clay.
Performance: Refractoriness 1580–1770℃, good thermal shock resistance, low cost.
Applications: Preheating and cooling zones of tunnel kilns, preheating zones of rotary kilns, low-temperature zones of shuttle kilns, and auxiliary parts such as flues and chimneys.
High-Alumina Bricks:
Composition: Al₂O₃ content 48%–90%, raw materials are bauxite and corundum.
Performance: Refractoriness 1770–2000℃, high mechanical strength, and superior erosion resistance compared to clay bricks.
Kiln Applications: Suitable for medium- and high-temperature areas such as the firing zone of tunnel kilns, the working layer of shuttle kilns, the transition zone of rotary kilns, and the regenerator chambers of glass kilns.
Sub-types: Anti-spasting high-alumina bricks: Designed specifically for kiln areas with large temperature fluctuations, reducing thermal shock spalling.
Phosphate-bonded high-alumina bricks: Require no high-temperature firing and can be used directly; suitable for wear-resistant parts such as kiln car platforms and furnace doors.
Siliceous Bricks:
Composition: SiO₂ content ≥93%, made from silica.
Performance: Refractoriness 1690–1730℃, excellent volume stability at high temperatures, and strong resistance to acidic slag erosion.
Kiln Applications: Suitable for the grid structure of glass kiln regenerator chambers, coke oven combustion chambers, and other parts of kilns with acidic atmospheres.
Magnesia Bricks:
Composition: MgO content ≥80%, raw material is magnesite.
Properties: Refractoriness above 2000℃, strong resistance to alkaline slag erosion, excellent high-temperature performance.
Applications: Cement rotary kiln firing zone, metallurgical kiln smelting zone, and other strongly alkaline erosion environments.
Sub-types: Magnesia-alumina spinel bricks (MgO-Al₂O₃), with better thermal shock resistance than pure magnesia bricks, are the mainstream brick type in cement kiln firing zones.
ZirconiumBricks:
Composition: Contains ZrO₂, common type is fused zirconia-corundum bricks (AZS bricks).
Properties: Refractoriness >2000℃, extremely strong resistance to molten glass erosion, good high-temperature chemical stability.
Applications: Bottom and side walls of glass kiln melting pools, special refractory bricks for the core parts of glass kilns.
Silicon Carbide Bricks:
Composition: SiC content ≥70%. Performance: Excellent thermal conductivity, wear resistance, thermal shock resistance, and high high-temperature strength.
Applications: Suitable for areas subjected to flame erosion and material wear, such as the burner zone of tunnel kilns, the feed inlet of rotary kilns, and the burner nozzle of shuttle kilns.