Silica brick: an acidic refractory mainly composed of tridymite, cristobalite and a small amount of residual quartz and glass phases. Its silica content is more than 94%, it has anti-acid slag erosion performance, high high temperature strength, high load softening temperature, long-term use in high temperature flower wells without deformation, but low thermal shock stability (heat exchange in water is 1-4 Second-rate).