High Bulk Density Micropored Sintered Alumina: Improving Thermal Shock and Wear Resistance in High-Performance Refractories

In steel, cement, ceramics and other high-temperature industries, refractory materials are exposed to severe thermal cycling, mechanical wear and complex high-temperature reactions. Refractory manufacturers therefore increasingly require.

high-purity refractory raw materials with high bulk density and improved thermal shock resistance.

Jiangsu Jingxin New Materials Co., Ltd. has developed High Bulk Density Micropored Sintered Alumina, also known as Micropored Sintered Alumina, as a high-performance alumina refractory raw material designed to achieve a balance between high density, wear resistance and thermal shock resistance through an optimized sintering process and engineered microstructure.

What Is Micropored Sintered Alumina?

Micropored Sintered Alumina is produced from industrial alumina and calcined alumina and sintered at high temperature in a vertical kiln. During production, the particle size distribution of the starting powders and the firing conditions are carefully controlled to regulate sintering, diffusion and mass transfer.

This process promotes corundum crystal growth while allowing more pores to be enclosed within the crystals. The resulting microstructure helps optimize internal stress distribution and reaction interface behavior during service.

The average crystal size is approximately 50–100 μm. According to product testing data, the thermal conductivity at 800°C is approximately 20% lower than that of conventional sintered alumina, supporting the coordinated improvement of high density and thermal shock resistance.

High Purity and High Bulk Density

High purity and stable physical properties are important for high-performance refractory raw materials. Jingxin Micropored Sintered Alumina contains ≥99.2% Al₂O₃, with controlled levels of Na₂O, SiO₂, Fe₂O₃ and magnetic iron.

Key specifications:

• Al₂O₃: ≥99.2%

• Na₂O: ≤0.40%

• SiO₂: ≤0.08%

• Fe₂O₃: ≤0.06%

• Magnetic Fe: ≤0.02%

• Bulk density: ≥3.58 g/cm³

• Apparent porosity: ≤4.50%

• Water absorption: ≤1.20%

Micro- and Nano-Porous Structure

One of the key characteristics of Micropored Sintered Alumina is its engineered internal pore structure. Compared with conventional sintered alumina, the crystal cross-section contains more micro- and nano-sized pores, which can contribute to improved bonding between the refractory aggregate and matrix.

When Micropored Sintered Alumina partially or completely replaces conventional tabular alumina in refractory products, it can provide higher bulk density and improved wear resistance. The optimized aggregate-matrix interface is also beneficial to the mechanical properties and thermal shock resistance of refractory products.

Thermal Shock and Wear Resistance

Thermal shock-induced cracking and spalling are important causes of refractory failure. The optimized microstructure of Micropored Sintered Alumina helps improve internal stress distribution during service.

Product testing shows that its thermal conductivity at 800°C is approximately 20% lower than that of conventional sintered alumina. Combined with high bulk density and a micro- and nano-porous structure, Micropored Sintered Alumina provides an additional raw material option for refractory formulations requiring a combination of density, wear resistance and thermal shock resistance.

Particle Sizes and Packaging

Jingxin can supply Micropored Sintered Alumina in particle and powder sizes ranging from 15 mm to 3 μm. Particle size can be selected according to the customer's refractory formulation, production process and application requirements.

Packaging options include:

• 25 kg bags

• 1,000 kg bags

• Customized packaging according to customer requirements

Conclusion

High Bulk Density Micropored Sintered Alumina is a high-purity, high-density synthetic refractory raw material featuring an engineered microporous corundum structure. By optimizing the internal pore structure and aggregate-matrix interface, the material can support improved wear resistance, mechanical properties and thermal shock resistance in refractory products.

With Al₂O₃ ≥99.2%, bulk density ≥3.58 g/cm³ and particle sizes available from 15 mm to 3 μm, Micropored Sintered Alumina provides refractory manufacturers worldwide with a flexible option for high-performance alumina-based refractory formulations. Jiangsu Jingxin New Materials Co., Ltd. can provide suitable particle sizes and packaging solutions according to customer requirements.