Zirconia Hollow Ball brick is a kind of insulating refractory product, the main material is zirconia hollow ball. (The principle crystalline phase of zircon hollow ball brick is cubic zirconia, account for about 70%~80% of mineral, refractoriness is more than 2400℃, the apparent porosity is 55%~60%, the volume density is 2.5~3.0 g/cm3, the compression strength is not less than 4.9 MPa, the thermal conductivity is 0.23~0.35w/(m·K). The production method of zirconia hollow ball insulation bricks are same as that of the Al2O3 oxide, just its fusion temperature is higher, can reach up to over 2700℃, at present, CaO is widely used as a stabilizer in China.
Production Methods of Zirconia Hollow Ball Bricks
The production method of zirconia hollow ball bricks are same as that of the Al2O3 oxide, just its fusion temperature is higher, can reach up to over 2700℃, at present, CaO is widely used as a stabilizer in China. The raw material is zirconia hollow ball (65%～70%) and zirconia powder, add boric acid aqueous as anchoring agent, molding by the vibration compression molding machine after uniform mixing, unfired brick is firing after drying at 1700~1800℃.
The zirconia hollow spheres used in raw materials are zirconia as raw materials, calcium oxide or yttrium oxide and Magnesium Oxide as stabilizers, which are uniformly mixed and melted by arc melting into compressed liquid, made of compressed air. Zirconia fine powder is made of zirconia as raw material, calcium oxide (or yttrium oxide and Magnesium Oxide) as stabilizer, uniformly mixed, fused to melt, and then produced by crushing and grinding.
Zirconia Hollow Ball Brick Parameters
ZrO2
≥99%
Fe2O3
≥0.2%
SiO2
≤0.2 %
Bulk Density
≥ 3.0g/cm³
Refractory under load
1700 (0.2MPa,0.6%)
Cold crushing strength
≥8Mpa
Linear change
±0.2 %(1600℃×2h)
Working temperture
2300
Zirconia Hollow Ball Brick Applications
Zirconia hollow ball brick is a kind if refractory product with good performance, the maximum safe use temperature is 2200℃, it is used in thermal equipment in the metallurgical, petrochemical engineering, electronic and other industrial thermal equipment as a direct contact flame high temperature lining material. Zircon hollow ball insulation bricks are fully made by the zirconia hollow ball, having the characteristics of good hot strength and stable pore structure, which can be used in the heat insulation material of furnace cover of extraordinary high temperature equipment, such as Medium frequency high temperature furnace, carbon black reactor, tungsten rod furnace and so on.
