Silicon brick belongs to acid refractory material, which has good acid corrosion resistance, good thermal conductivity and soft load the melting temperature is high, generally above 1620 ℃, which is only 70 ~ 80 ℃ lower than its fire resistance. 

The volume of silicon brick increases with the increase of temperature without residual shrinkage and increase. Therefore, silicon brick is an ideal refractory product in coke oven and an important part of modern large and medium-sized coke oven (e.g combustion chambers, ramps and regenerators) are built with silicon brick.

 Properties of silica brick

In the process of baking, the maximum expansion of silicon brick occurs between 100 ~ 300 ℃, and the expansion before 300 ℃ is about half of the total expansion70%~75%. The reason is that there are four crystal forms of SiO2: 117 ℃, 163 ℃, 180 ~ 270 ℃ and 573 ℃ during drying.The volume expansion caused by cristobalite is the largest between 180 ~ 270 ℃.

The key to the thermal stability of silica brick is the true density, which is one of the important symbols to determine its quartz transformation.The smaller the true density of silica brick, the more complete the lime conversion, and the smaller the residual expansion in the process of baking.

 In the silica brick, the true density of scaly quartz crystal is the smallest, the linear expansion rate is small, the thermal stability is better than quartz and quartz, and it is resistant to slag erosion. It has strong thermal conductivity and high softening temperature under load. It is the most stable form in quartz. Among the silica bricks with good firing, scaly stone.

The content of English is the highest, accounting for 50% ~ 80%; Calcite takes the second place, accounting for only 10% ~ 30%; The content of quartz and glass phase fluctuates 5%~15%。