Regarding the classification of refractory raw materials, countries around the world are not completely consistent. According to chemical properties, they are divided into acidic refractory raw materials, alkaline refractory raw materials and neutral refractory raw materials. However, refractory raw materials are usually divided into Al2O3-SiO2 series refractory raw materials, alkaline refractory raw materials, insulating refractory raw materials, and other refractory raw materials.
Al2O3-SiO2 series refractory raw materials: silica, pyrophyllite, refractory clay and its clinker, bauxite, mullite, corundum, industrial alumina and alpha alumina, etc.
Alkaline refractory raw materials: calcined materials or electric melting materials of limestone, dolomite, magnesite, forsterite, magnesia-aluminum spinel, magnesia-chromium spinel sand, etc.
Insulating refractory raw materials: perlite, vermiculite, diatomaceous earth, refractory fiber and hollow balls, etc.
Other refractory raw materials: zircon (including zirconium oxide), chromite, graphite, nitrides and borides, etc.
| project | bauxite | Mullite | White Corundum | brown corundum | α alumina |
| Al2O3；% | 80-90 | 40-70 | ≥99 | ≥95 | ≥99 |
| Fe2O3；% | 2.0-1.2 | 1.0-0.5 | ≤0.1 | ≤0.1 | ≤0.1 |
| TiO2；% | 4.0-3.0 | 1.5-0.5 | ≤0.1 | ≤1.5 | ≤0.1 |
| K2O+Na2O；% | ≤0.4 | ≤0.3 | ≤0.35 | ≤0.3 | ≤0.3 |
| Bulk density；g/cm3 | 3.0-3.4 | 2.6-2.9 | ≥3.6 | ≥3.9 | / |
| water absorption；% | ≤4.0 | ≤0.5 | / | / | |
| Mullite content；% | / | 60-90 | / | / | / |
| The average grain size；μm | / | / | / | / | 3-5 |
