The properties of refractory brick:
1. Chemical composition: the main ingredients determine the quality and characteristics of corundum block.
2. The bulk density: per unit volume weight, density is large, indicating the density is good, the strength may be high, but the thermal conductivity may be large.
3. The porosity: no specific requirements, but as a manufacturer must strictly control the hole.
4. Load softening temperature: also known as high temperature load starting deformation temperature, this parameter is very important, marking the material resistance to high temperature.
5. Thermal shock resistance: resistance to the rapid changes in temperature and without the ability to damage.
6. Compressive strength: to withstand (room temperature) the maximum pressure capacity.
First of all,
the most basic is the nature of silica brick belongs to the acidity.
The true density of silica brick is
smaller, the lime translation is more complete, in the process of the oven and
residual expansion is smaller. In silica brick, the true
density of the quartz crystal is smallest, linear expansion
rate is small, the thermal stability is better than cristobalite and
quartz, thermal conductivity is good, refractoriness under load is high, slag
corrosion resistance is strong, is the most stable form quartz in volume.
In better firing silica brick, the content of
scale quartz is the highest, accounted for 50% ~ 80%, cristobalite
times, only 10% ~ 30%, the content fluctuation of quartz and
glass phase is in 5% ~ 15%.
When working temperature is below 600 ~ 700 ℃, silica brick volume change is bigger, the resistance to thermal shock performance is poorer, thermal stability is not good. If coke oven is in long-term work under this kind of temperature, masonry is easily broken.
The key to determine whether thermal stability is good is true density, the size of true density is to determine one of the important marks of the quartz translation.
Silica brick belongs to the acid refractory material, with good acid erosion resistance, its thermal performance is good, refractoriness under load is high, generally is above 1620 ℃, the refractoriness is only lower 70 ~ 80 ℃ . The thermal conductivity of silica brick increases with the rising of temperature, no residual shrinkage, in the process of oven, the volume of a silica brick increases as the temperature increases.