Two Factors for the Compactness of Silica Brick

Silica brick belongs to the SiO2-Al2O3 refractories and is mainly used in coke oven, glass furnaces, blast furnaces and calciner. The quality of silica brick is not only influenced by the content of SiO2 but also its compactness. 

The density and sintering capability of silica brick is two main factors that influence its compactness. The densest silica brick is not necessarily the silica brick with the lowest porosity. When the additives are the same, the particle size (<0.088mm %/the critical particle size %) determines its sintering capacity.

 

When the critical particle size is 3mm and the particle size coefficient is 0.75-1.00, silica brick hass good porosity, density and appearance. When the critical particle size is different, the brick has different particle size coefficient. The particle size coefficient increases with the critical particle size. When the critical size increases, the brick contains more fine-particle. Practice has proved that the potential of cracking and the density decreases with the decreasing of the silica brick. 

 

In order to increase the amount of tridymite, reduce the volume change and cracks and improve the yield, a smaller critical size is better. The critical particle size of silica brick is generally 2-3mm. When quartz is used as the raw material, the maximum particle size is 2mm.