Silica bricks for glass kilns refer to silica refractory products used in high-temperature parts of glass kilns (not in contact with glass liquid). Glass kilns are complex and large masonry built of various refractory materials, and their vaults are mostly made of silica bricks. Breast walls and port were once all made of silica bricks, but since the 1970s, some have been replaced by fused zirconium corundum or β-alumina products. Silica bricks are also used in the vaults and checker bricks of the heat storage chambers of some glass kilns.

The top of the melting part and cooling part of the glass melting furnace (including the arch angle) is at a working temperature of 1600℃. The refractory materials used in these parts must be able to withstand high temperature, load, and the scouring effect of alkali vapor and batch materials. Therefore, the refractory materials used as the top must have extremely high refractoriness, high load softening temperature and good creep resistance, and low thermal conductivity. The refractory materials at high temperature cannot pollute the glass liquid. The bulk density of the material must also be small and the high temperature strength is good.

Performance of silica bricks for glass kilns

(1) Stable volume at high temperature, will not cause changes in the furnace body due to temperature fluctuations. Due to the high load softening temperature and low creep rate of silica bricks, the glass kiln can keep the furnace body unchanged at 1600°C and has a stable structure;

(2) No pollution to glass liquid. The main component of silica bricks is SiO2. If there is block drop or surface droplets during use, it will not affect the quality of the glass liquid;

(3) Resistant to chemical corrosion. The silica bricks of the upper structure are corroded by the R2O gas in the glass batch, and a smooth metamorphic layer is formed on the surface, which reduces the erosion rate and plays a protective role;

(4) The volume density is small, which can reduce the weight of the furnace body.

(5) The price is cheap, which can reduce the construction cost.

Therefore, high-purity and high-quality silica bricks have become the first choice in the production process of various glasses. The chemical erosion caused by the high-temperature chemical reaction of waste materials and alkali vapor with refractory materials, as well as the crystal transformation and structural density changes caused by phase migration and temperature are the main reasons for the damage of arch top bricks. The research results show that the corrosion process of high-quality glass kiln silica bricks used in arch tops under the high temperature of the kiln is basically caused by impurity migration and impurity phase change, and chemical erosion and melting can be basically ignored. The effects of phase change and self-purification gradually change the performance of the kiln operation zone, and its high-temperature performance is improved.