Al-Mg refractory castables are prepared by electrofused magnesium sand, sintered magnesium sand, electrofused or sintered magnesium-aluminum spinel, electrofused corundum, alumina powder, high alumina powder, etc. According to the quality of raw materials used, it can be divided into: common aluminum-magnesium castables, common high alumina-spinel castables, alumin a-magnesium oxide castables, alumina-spinel castables, corundum-spinel castables.
Ordinary Al-Mg castables are used for the overall lining of continuous casting ladles.
Ordinary high alumina-spinel castables are composed of high alumina bauxite aggregate with powder, bauxite and sintered spinel aggregate with powder. It is suitable for small and medium-sized continuous casting ladle overall lining, intermediate ladle permanent lining and electric furnace steel discharge chute lining etc.
The aggregate of alumina-magnesia castables is made of fused white corundum, or slab alumina, or fused high alumina corundum. It is generally used for the overall lining below the slag line of large ladle, and the use cycle is more than 1 times higher than that of common alumina-magnesia castables, and it can also be used as the lining of other high temperature furnaces, vessels and flow channels.
Alumina-spinel castables and corundum-spinel castables are mainly used for large ladle body lining and also for high power electric furnace cover lining.
Al-Mg refractory castables performance index
| Item | AMC-70 | AMC-80 | AMC-85 | AMC-95 | |
| ω(Al2O3+MgO)/% ≥ | 70 | 80 | 85 | 95 | |
| Bulk density(110℃×24h after drying)/(g/cm³) ≥ | 2.6 | 2.8 | 2.85 | 2.95 | |
| Normal temperature compressive strength, MPa | 110℃×24h after drying ≥ | 20 | |||
| 1000℃×3h after firing ≥ | 30 | ||||
| Test temperature×3h after firing ≥ | 50(1500℃) | 50(1550℃) | 60(1550℃) | 60(1600℃) | |
| Heating permanent line change, % | Test temperature×3h | -0.5~+1.5 (1500℃) | -0.5~+1.8 (1550℃) | -0.2~+1.8 (1550℃) | 0~+1.0 (1600℃) |
