A coke oven is a complex, long term continuous use thermal equipment. Its purpose is to dry distill coal by heating it to 950-1050℃ under the condition of air isolation, so as to obtain coke and other by-products. Silica bricks have become the main refractory material for coke ovens because of their good thermal conductivity, high load softening temperature, good high temperature mechanical strength and stable high temperature volume change, refractoriness, small residual expansion, and strong resistance to acid slag erosion.
Silica bricks for coke ovens are used in all major parts of coke ovens: heat storage chamber wall, ramp, carbonization chamber bottom, furnace wall and roof.
The application of silica bricks for coke ovens can increase the temperature of combustion chamber, shorten the coking time, increase the production capacity of coke oven and prolong the age of coke oven, so modern large coke ovens are mainly built with silica bricks.
| Silica bricks for coke oven | Furnace bottom, furnace wall | Other |
| SiO2 % ≥ | 94.5 | 94 |
| Al2O3 % ≤ | 1.2 | 1.5 |
| Fe2O3 % ≤ | 1.2 | 1.5 |
| CaO % ≤ | 3.0 | 3.0 |
| Na2O+K2O % ≤ | 0.35 | 0.35 |
| Apparent porosity % ≤ | 22 | 24 |
| Normal temperature compressive strength MPa ≥ | 35 | 28 |
| 0.2MPa Load softening temperature℃ ≥ | 1650 | |
| True Density g/cm3 ≥ | 2.33 | 2.34 |
| Reburn line change % 1450℃x2h | 0-0.2 | |
| Coefficient of thermal expansion 1000℃ % ≤ | 1.28 | 1.3 |
