Zirconium mullite bricks are a special refractory material made by introducing zirconium oxide (ZrO₂) into traditional mullite bricks, aiming to improve the overall performance of the material in harsh high-temperature environments. Its core characteristics are reflected in the following aspects:
1. Excellent thermal shock stability
This is the most prominent advantage of zirconia mullite bricks. The introduced zirconium oxide undergoes a reversible phase transformation of its crystal structure during heating and cooling. This phase transformation, accompanied by volume changes, can absorb or offset the thermal stress caused by rapid temperature fluctuations, effectively preventing material cracking. Therefore, it can withstand frequent and drastic temperature changes; for example, under water cooling conditions at 1100℃, its thermal shock stability can reach more than 10 cycles.
2. Excellent resistance to erosion and chemical corrosion
Zirconium mullite bricks have high chemical stability and strong resistance to molten glass, alkaline media, and various slags. This makes them an ideal choice for glass furnace linings, effectively resisting the erosion of high-temperature melts and significantly extending the service life of the furnace.
3. High load softening temperature and high-temperature strength
Zircon mullite bricks exhibit a high load softening temperature, typically exceeding 1580℃ to 1700℃, indicating their resistance to deformation under combined high temperatures and loads. Simultaneously, the dispersion strengthening effect of zirconium oxide contributes to their high mechanical strength at both room and high temperatures, ensuring structural stability at high temperatures.
4. Dense microstructure
Zircon mullite bricks generally possess high bulk density (typically above 2.6 g/cm³ to 3.2 g/cm³) and low apparent porosity (typically ≤17-18%). This dense structure not only enhances their resistance to permeation and erosion but also provides good thermal conductivity and wear resistance.
Based on these characteristics, zircon mullite bricks are widely used in critical components of thermal equipment with stringent material requirements, such as the arches, regenerators, and pool walls of glass furnaces, as well as the linings of high-temperature furnaces in the metallurgical and chemical industries.