What Is Corundum Spinel Castable - Insulation Refractory Product

Corundum spinel castable is a high-performance refractory material primarily composed of corundum (Al₂O₃) and spinel (MgAl₂O₄) as the main aggregates, supplemented with matrix materials such as magnesia fine powder and silica micro powder, and bound with calcium aluminate cement as the binder. Its key feature is the formation of a stable mineral phase structure at high temperatures, which combines excellent slag corrosion resistance, thermal shock resistance, and volume stability.

1.Raw Material Composition

The main raw materials include:

Aggregates: Corundum and spinel, with melting points of 2050 °C and 2135 °C respectively, provide high-temperature strength and wear resistance.

Matrix: Magnesia fine powder, silica micro powder, α-Al₂O₃ micro powder, etc., are used to adjust volume expansion and density.

Binder: Calcium aluminate cement enhances bonding strength.

2.Performance Characteristics

High-temperature stability: After high-temperature treatment, high melting-point mineral phases such as calcium hexaaluminate (CA₆) and magnesium aluminate spinel (MA) form an interlocking matrix structure, significantly improving slag corrosion resistance and reducing permeability.

Volume stability: The volume expansion resulting from in-situ spinel formation contributes to a dense structure, though the expansion must be controlled to prevent cracking.

Thermal shock resistance: The addition of additives such as silica micro powder helps balance shrinkage and expansion, thereby optimizing thermal shock performance.

3.Application Scenarios

Corundum spinel castable is widely used in linings for high-temperature industrial furnaces such as ladle working layers, blast furnaces, and heating furnaces. It is particularly suitable for applications requiring high wear resistance and slag corrosion resistance.

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