Jun 30, 2021
Corundum Refractory Bricks
Rebonded fired corundum bricks are made from sintered corundum aggregates and fines. The production process of fired corundum bricks is: batch material formulation, mixing, tempering, machine pressing, high-temperature sintering. RS-produced corundum bricks have better thermal shock resistance and slag corrosion resistance than other products, because a little amount of synthesized mullite clinker, silica, kyanite, or sillimanite concentrate powder is added into raw materials to form mullite during sintering. The quantity of fine powders also has a significant influence on corundum brick density and strength, the increase of fine powder can greatly increase corundum brick density and strength, especially the addition of ultra-micro powder greatly improves corundum bricks high-temperature performance.
Fired corundum bricks physiochemical indexes
| Item | SJGZ-1 | SJGZ-2 | SJGZ-3 | SJGZ-4 | SJGZ-5 |
| SiO2 % | 0.15 | 0.24 | 0.28 | 0.11 | 0.48 |
| Al2O3 % | 99.51 | 99.30 | 98.82 | 99.60 | 97.42 |
| Fe2O3 % | 0.11 | 0.08 | 0.01 | 0.04 | 0.06 |
| R2O % | 0.026 | 0.12 | / | 0.14 | 0.43 |
| Apparent porosity % | 18 | 16.2 | 17~18 | 18 | 19 |
| Bulk density g/cm3 | 3.20 | 3.23 | 3.25~3.26 | 3.23 | 3.09 |
| Crushing strength Mpa | 133.5 | 96 | 85.2~90.4 | 106.59 | 96.2 |
| Refractoriness under load ℃ | >1700 | >1800 | >1700 | >1700 | >1700 |
| Reheating linear change rate % | 0~+0.1 | / | / | 0~±0.1 | -0.3 |
| Thermal shock resistance/times (1100℃, water cooling) | 23 | 18 | >20(1000℃, air cooling) | 13 | / |
Rebonded fused corundum bricks are made from fused corundum clinker aggregate and fine powders. During fused corundum bricks production, the raw materials are strictly selected to promise the good quality of corundum bricks. For brown corundum bricks production, brown corundum contained ferrosilicon or other impurities should be removed. For white corundum bricks production, flake-like crystalline sodium aluminate and other eutectics should be removed.
Fused corundum bricks have high purity, therefore, the sintering of fused corundum bricks is difficult, sintering temperature should be higher than 1800℃. RS ultra-high-temperature periodic kiln is specialized for fused refractory brick production.
Fused corundum bricks physiochemical indexes
| Item | α-corundum bricks | a-β corundum bricks | β corundum bricks |
| SiO2 % | <0.5 | <1.5 | <0.5 |
| Al2O3 % | >99 | >94 | >94 |
| Fe2O3 % | <0.1 | <0.1 | <0.1 |
| Na2O % | <0.8 | <4.5 | <7 |
| MgO % | <0.1 | <0.1 | <0.1 |
| TiO2 % | <0.1 | <0.1 | <0.1 |
| Apparent porosity % | 0~20 | 0~5 | 5~15 |
| Bulk density g/cm3 | >3.8 | >3.4 | >3.0 |
| Modulus of rupture Mpa | >70 | >150 | >20 |
| Refractoriness ℃ | >1900 | >1875 | >1875 |
RS Kiln Refractory not only has rich experience in corundum bricks production but also produces composite corundum bricks, such as chrome corundum bricks, zirconia corundum bricks, titania corundum bricks, and so on. Some properties of composite corundum bricks are better than pure corundum bricks.
RS Kiln Refractory customized service
RS Kiln Refractory not only supplies regular refractory products but customizes various kinds of products. The whole series of corundum bricks: α-corundum bricks, β corundum bricks, a-β corundum bricks, fired corundum bricks, fused corundum bricks, white corundum bricks, brown corundum bricks, sub-white corundum bricks, tabular corundum bricks and so on all can be customized according to application fields and purity requirement.
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