Introduction to Mullite Bricks

When it comes to high - temperature industrial applications, choosing the right refractory material can be a daunting task for global buyers. Mullite bricks have emerged as a popular choice due to their excellent refractory properties. Understanding the classification and characteristics of mullite bricks is crucial for making an informed purchasing decision.

Types of Mullite Bricks and Their Features

Sintered Mullite Bricks

Sintered mullite bricks are made from natural bauxite or synthetic mullite powder. The raw materials are first crushed, mixed, and then shaped into brick forms. They are then sintered at high temperatures, usually between 1600 - 1800°C. These bricks have a relatively low bulk density, around 2.3 - 2.6 g/cm³, which makes them lightweight. Their porosity ranges from 18% - 22%, providing good insulation properties. Sintered mullite bricks also have high refractoriness, with a refractoriness under load (RUL) of about 1500 - 1600°C, making them suitable for applications where heat insulation and moderate heat resistance are required.

Fused Cast Mullite Bricks

Fused cast mullite bricks are produced by melting high - purity alumina and silica raw materials in an electric arc furnace at extremely high temperatures, typically above 2000°C. After melting, the molten material is cast into molds and slowly cooled. These bricks have a very dense structure, with a bulk density of about 2.8 - 3.0 g/cm³. Their porosity is extremely low, less than 5%. Fused cast mullite bricks offer superior corrosion resistance and mechanical strength. They can withstand temperatures up to 1700 - 1800°C and have a high refractoriness under load, reaching 1650 - 1750°C.

Comparison between Sintered and Fused Cast Mullite Bricks

Application Scenarios

Sintered mullite bricks are commonly used in the lining of heating furnaces, ladles, and some parts of glass furnaces where heat insulation is the main requirement. Fused cast mullite bricks, on the other hand, are ideal for the most demanding high - temperature applications, such as the critical parts of glass furnaces, ceramic kilns, and some petrochemical reactors due to their high corrosion resistance and mechanical strength.

Conclusion

In conclusion, both sintered and fused cast mullite bricks have their own unique characteristics and are suitable for different high - temperature applications. When choosing mullite bricks, global buyers should carefully consider their specific requirements, such as temperature resistance, insulation needs, and corrosion resistance. By understanding these factors, they can make a more informed purchasing decision.