A raw material with a high content of aluminum oxide has the following composition,
in weight-percent, based on dry weight:
|
| Al2O3 |
50-80% |
| MgO |
2-15% |
| SiO2 |
1-15% |
| CaO |
0.5-20% |
| Fe2O3 |
0.5-2% |
| Na2O |
0.5-2% |
| Al (metallic) |
0.1-2% |
| AlN |
0.1-1% |
| K2O |
0.1-1.5% |
| F |
0.1-2% |
| Cl |
0.1-0.8% |
| balance in total, not to exceed |
5% |
| loss on ignition, not to exceed |
15% |
|
The main mineral constituents of the raw material are, in weight-percent
|
| aluminum hydroxide |
20-60% |
| corundum -Al2O3 |
10-40% |
| spinel MgAl2O4 |
5-40% |
|
Specifically, the aluminum hydroxide is present as aluminum mono-hydroxide
Al2O3.H2O and aluminum tri-hydroxide Al2O3.3H2O
in a weight ratio exceeding 0.25.
