Introduction
High aluminna aggregate, also known as bauxite, is mainly composed of Al2O3. High-alumina bauxite chamotte is an excellent refractory material processed from bauxite raw material through selection, high temperature roasting, crushing, sorting and other processes.
High alumina aggregate is also called refractory aggregate. It is a granular material processed on the basis of high-alumina bauxite chamotte through crushing, screening, iron removal and other processes. The Al2O3 content of high-alumina aggregate is generally more than 70%. It is the main raw material for making refractory materials, refractory bricks, castables, gunning materials, refractory furnace materials and other unshaped refractory materials.
Characteristics of High Alumina Aggregate
- High Aluminum Content
- Low Iron Content
- High Hardness
- Low Thermal Expansion Coefficient
- High Fire Resistance
- High Density
- Stable Thermochemical Properties
Classification of High Alumina Aggregate
High alumina aggregate is mainly divided into different grade based on the Al2O3 content.
| Grade | AL2O3 | Fe2O3 | Ti02 | CaO+MgO | K20+Na20 | Bulk Density g/cm3 | Water Absorption % |
| GL-88 | ≥88 | ≤1.5 | ≤4.0 | ≤0.4 | ≤0.4 | ≥3.15 | ≤4 |
| GL-85 | ≥85 | ≤1.8 | ≤4.0 | ≤0.4 | ≤0.4 | ≥3.10 | ≤4 |
| GL-80 | ≥80 | ≤2.0 | ≤4.0 | ≤0.5 | ≤0.5 | ≥2.90 | ≤5 |
| GL-70 | >70–80 | ≤2.0 | – | ≤0.6 | ≤0.6 | ≥2.75 | ≤5 |
| GL-60 | >60–70 | ≤2.0 | – | ≤0.6 | ≤0.6 | ≥2.65 | ≤6 |
| GL-50 | >50–60 | ≤2.5 | – | ≤0.6 | ≤0.6 | ≥2.45 | ≤6 |
Application of High Alumina Aggregate
- High alumina aggregate is an indispensable raw material in refractory castables.
- It can be mixed with high-alumina cement, fine powder and in proportion to produce refractory concrete castables with very high strength;
- It is also the main raw material for making refractory materials, refractory bricks, castables, gunning materials, refractory furnace materials and other unshaped refractory materials.
