Bubble alumina brick is a new type of high temperature insulation material. It is made by melting and blowing industrial alumina in electric furnace. With alumina bubble as the main part, it can be made into various shapes of products with a maximum operating temperature of 1800℃.
The mechanical strength of these products is high, several times that of general lightweight products, while the bulk density is only one-half that of corundum products.
Bubble alumina brick is widely used in petrochemical industry gasification furnace, carbon black industry reaction furnace, metallurgical industry induction furnace and other high temperature, ultra-high temperature kilns, and achieved very good energy-saving effect.
| Index | Level I | Level II | Level III |
| Al2O3, % | ≥98 | ≥98 | ≥98 |
| SiO2, % | ≤1 | ≤1 | ≤1 |
| Fe2O3, % | ≤0.7 | ≤0.7 | ≤0.7 |
| Refractoriness, ℃ | ≥1790 | ≥1790 | ≥1790 |
| Refractoriness under Load, 0.1MPa, ℃ | ≥1600 | ≥1600 | ≥1600 |
| Bulk density, g/cm3, ≤ | 1.2 | 1.4 | 1.6 |
| True porosity, %, ≥ | 62 | 60 | 58 |
| Cold crushing strength, MPa, ≥ | 3 | 10 | 12 |
| Thermal Conductvity, 1100℃, W.(m.k), ≤ | 0.93 | 1.04 | 1.16 |
