High alumina brick is a kind of refractory, the main component of which is Al2O3. If Al2O3 content is higher than 90%, it is called corundum brick. Due to different resources, the standards of different countries are not completely consistent. For example, in European countries, the lower limit of Al2O3 content for high alumina refractories is 42%. In China, Al2O3 content in high alumina brick is generally divided into three grades: Grade I – Al2O3 content > 75%; grade II – Al2O3 content is 60-75%; grade III – Al2O3 content is 48-60%.
1.High refractoriness
2.High-temperature strength
3.High thermal stability
4.Neutral refractory
5.Good resistance to acid and basic slag corrosion
6.High refractoriness under load
Items | First grade
high alumina brick |
Second grade
high alumina brick |
Third grade
high alumina brick |
Special grade
high alumina brick |
LZ-75 | LZ-65 | LZ-55 | LZ-80 | |
Al2O3 % ≥ | 75 | 65 | 55 | 82 |
Fe2O3 % ≤ | 2.5 | 2.5 | 2.6 | 2.0 |
Bulk Density g/cm3 | 2.5 | 2.4 | 2.3 | 2.6 |
Cold Crushing Strength MPa ≥ | 70 | 60 | 50 | 80 |
0.2MPa Refractoriness Under Load ℃ | 1510 | 1460 | 1420 | 1550 |
Refractoriness ℃ ≥ | 1790 | 1770 | 1770 | 1790 |
Apparent Porosity % ≤ | 22 | 23 | 24 | 21 |
Reheating Linear Change 1450℃×2h % | -0.3 | -0.4 | -0.4 | -0.2 |
High alumina bricks are popularly used for the masonry of industrial kilns’ inner linings, such as blast furnaces, hot blast furnaces, electric furnace top, reverberator, rotary cement kiln, and so on. Besides, high alumina bricks are also widely used as regenerative checker bricks, stopper of the continuous casting system, nozzle bricks, etc.