Silicon thermal insulation refractory brick refers to the thermal insulation refractory products made of silica as the main raw material, with a SiO2 content of no less than 91%. In addition to the heat insulation performance, the silicon heat insulation refractory brick maintains the characteristics of the silicon brick to a large extent, and the load softening temperature is high. In the heating process, the volume is slightly expanded, which enhances the integrity of the kiln. The manufacture of silica thermal insulation refractory brick adopts the finely crushed silica as raw material, adding part of the waste silicon brick or waste silica heat insulation refractory brick powder, mineralizer and burned out addition. According to a certain ratio, water is mixed in the mixing machine into mud material. After mechanical or manual molding, the brick residual water less than 0.5% can be installed in the kiln. In order to prevent the violent volume expansion because of the SiO2 polycrystalline transformation, which causes cracks in the products, the relatively slow lifting temperature speed is required when firing.

Performance of QG-1.2 brick for industrial furnace stipulated in the industry standard of YB 386-63 of the Ministry of Metallurgical Industry: the volume density is not more than 1.2 g/cm3, the normal temperature withstand pressure strength is not less than 3.43MPa, the fire resistance is not less than the starting temperature of load softening under 1670℃,0.098MPa is not less than 1560℃. 

Besides, the silica refractory bricks are suitable for industrial furnace lining whose working temperature does not exceed 1550℃, does not directly contact with high temperature molten materials and is not directly affected by erosive gas, or are used for heat insulation layer.

Because silica dust is harmful to human body, the process is more complicated than clay and high aluminum heat insulation and refractory brick, which accounts for a small proportion in the total output of heat insulation and refractory material.