Zirconia bricks are refractory products produced with zirconia as the main raw material. Zirconia has a high melting point, strong high-temperature structure and resistance to acid and alkali corrosion. The manufacturing method mainly includes two kinds of firing method and fusion casting method. There are three crystal forms of zirconia: monoclinic, tetragonal and cubic. When zirconium oxide is heated to about 1100°C, the crystal form changes from monoclinic to tetragonal, accompanied by 7% volume shrinkage, and vice versa. The tetragonal zirconia will appear cubic crystal form above 2300℃. The densities of the three crystal forms are 5.68g/cm3 (monoclinic), 6.10g/cm3 (tetragonal), and 6.27g/cm3 (cubic).
1. Dense zirconia brick is formed by isostatic pressing method, its technical index is ZrO2>65%, apparent porosity<2.0%, bulk density is about 4.25g/cm3, in E glass, there will be corrosion if the temperature exceeds 1370℃. It is used in the bottom of the melting part where the temperature of the molten glass is slightly lower in the E glass unit kiln, the transition channel, the bottom of the forming channel, the flow tank of the forming channel and the slat bracket, etc. In addition, dense zirconia bricks are also used as backing bricks for dense chrome bricks.
In recent years, Chinese refractory companies have introduced foreign technology and equipment, and have also produced sintered dense zirconium bricks formed by isostatic pressing, which have been partially used in domestic glass and fiberglass kilns.
German company has developed a new type of dense zirconia brick with coarse-grained structure, which greatly improves the internal structure of the brick, and further improves the resistance to rapid cold and heat of the brick. Its bulk density is 3.75g/cm3, and its porosity is 17%. The brick grade is ZS65AR, which has good thermal shock resistance, and is most suitable for drawing liquid troughs and slab holding bricks.
2. Standard zirconia brick
The ZrO2 content of the brick is about 66%, and the bulk density is 3.7g/cm3, which has good thermal stability and peel resistance. Used in the breast wall and back wall of the feeding port area where powder erosion is more serious, the breast wall and roof brick of the furnace observation hole brick and the passage flame space, and the burner brick.
Zibo Zhongze New Material Technology Co., Ltd. is located in Zibo High-tech Industrial Development Zone, Shandong Province. It is a comprehensive enterprise with alumina balls, filler balls, wear-resistant lining bricks, ZTA zirconium-aluminium composite ceramics and other produc···