December 17, 2025
Corundum brick is a dense alumina-based refractory designed for operating environments where temperature, load, and chemical stress act simultaneously over long production cycles. Unlike conventional refractory brick materials that rely on mixed mineral phases, corundum brick is built around a dominant corundum crystal structure formed from ultra-high-purity alumina raw materials. This structural foundation directly determines its performance behavior in extreme industrial conditions.
The defining feature of corundum brick lies in its phase composition. With alumina content commonly exceeding 90%, the firing process promotes direct crystal bonding between corundum grains, resulting in a compact microstructure with minimal glassy phase. This limits softening at high temperatures and allows corundum brick to maintain mechanical strength under sustained thermal load. In applications where furnace linings are exposed to temperatures above 1700°C, corundum brick shows stable volume retention and reduced deformation compared with lower-alumina alternatives.
Chemical stability is another critical performance factor. Corundum brick exhibits low reactivity with acidic and alkaline slags due to the chemical inertness of alumina at high temperatures. This property is particularly important in metallurgical furnaces where slag composition fluctuates during production. The dense structure of corundum brick restricts slag penetration, slowing chemical erosion and preserving lining thickness throughout extended campaigns.
From a mechanical perspective, corundum brick offers high cold crushing strength and strong resistance to abrasion. These properties make it suitable for furnace zones exposed to material impact, mechanical vibration, or high-speed gas flow. In areas such as furnace hearths, burner surrounds, and charging ports, corundum brick reduces surface wear and structural damage, contributing to longer refractory service intervals.
Thermal behavior of corundum brick is closely linked to its controlled porosity and grain distribution. While dense refractories are often sensitive to temperature fluctuations, optimized corundum brick formulations can tolerate operational temperature changes when proper heating and cooling protocols are followed. This balance between density and thermal stability supports use in both continuous furnaces and batch-operated thermal systems.
Corundum brick is widely applied in steelmaking furnaces, ladles, tundishes, and hot blast systems, where high-temperature strength and slag resistance are essential. In non-ferrous metallurgy, it is used in aluminum and copper melting furnaces to limit metal infiltration and chemical interaction. Glass manufacturing, petrochemical processing, and hazardous waste incineration also rely on corundum brick for zones requiring structural reliability under aggressive thermal and chemical conditions.
Installation quality directly influences the performance of corundum brick. Accurate brick machining, proper refractory mortar selection, and allowance for thermal expansion are essential to avoid stress concentration during operation. When correctly installed, corundum brick forms a stable working lining that supports long furnace campaigns and predictable maintenance planning.
As industrial processes continue to evolve toward higher efficiency and higher operating temperatures, corundum brick remains a technically reliable refractory solution. Its performance is not based on insulation or lightweight design, but on structural integrity and chemical endurance, making corundum brick a critical material for high-demand thermal systems where failure tolerance is minimal.
