Silica Bricks Definition
It is a refractory product with silicon dioxide (SiO2) content not less than 93%. It belongs to acid silica brick refractory material, has good acid resistance and slag erosion, the refractoriness under load can up to 1640~1670 DEG C, the volume is stable under the high temperature for long-time using.
Silica Bricks Compositions
It is a kind of acid refractory material mainly made of Tridymite, cristobalite and a small amount of residual quartz and glass phase. Due to crystal phase change, the volume change of Tridymite, cristobalite and quartz remaining at low temperature is great, so the thermal stability of silica brick is poor at low temperature. In the course of use, it should be slowly heated and cooled below 800 centigrade so as not to produce cracks. So it is not suitable for the kiln which has sharp temperature changes below 800℃
Physical and Chemical Index of Silica Brick
| Product Index | High-quality silica bricks | |
| SiO₂ % ≥ | 95 | 96 |
| Fe₂O₃ % ≤ | 1.2 | 0.8 |
| CaO % ≤ | 2.5 | 2.5 |
| True Density g/cm³ | 2.34 | 2.34 |
| Refractoriness ℃ | 1710 | 1730 |
| 0.2 MPa Refractoriness under Load ≥℃ | 1650 | 1680 |
| Apparent porosity % | 22 | 22 |
| Cold Crushing Strength ≥MPa | 29.4 | 35 |
| Reheating Linear Change（1450℃× 2h）% | +0.2 | +0.2 |
Silica Bricks Properties
- Good acid erosion resistance
- High-temperature strength
- High RUL: about 1620-1670℃
- Volume stability at high temperature
- Good thermal shock resistance
Silica Bricks Application
- The partition of the carbonization chamber of coke oven and combustion chamber
- The regenerator and slag chamber of the steel-making open-hearth furnace
- Regenerator and slag pocket of the steeling-making open-hearth furnace;
- Soaking pit, and glass kiln;
- High temperature bearing parts of the hot blast furnace;
- The roof of an acid open hearth, and chute;
- Arch and other supporting parts of the ceramic kilns and refractory bricks kilns, etc.
