In the melting pool of glass kiln, silica brick plays a particularly important role, which is mainly reflected in the following aspects:

I. Corrosion resistance

The main component of silica brick is silica (SiO₂), and its content usually exceeds 96%. This composition is the same as the main composition of glass melt, so under the condition of high temperature, the erosion of silicon brick will basically not pollute the glass melt.

The metamorphic layer formed by silicon brick at high temperature can play a protective role and slow down the erosion rate. For example, below 1600℃, a smooth metamorphic layer will be formed on the surface of silicon brick, which can effectively resist the corrosion of alkali metal gas.

II. High temperature stability

Silicon brick has a high softening temperature under load, which is close to its fire resistance. In the melting pool of glass kiln, the temperature is usually between 1560℃ and 1670℃, and the silicon brick can remain stable in such a high temperature environment without deformation or melting.

Silicon brick has good high temperature strength and creep resistance, and can maintain structural integrity in long-term high temperature operation.

III. Economy

The price of silicon brick is relatively low, which can effectively reduce the production cost while ensuring the performance of the melting pool in the glass kiln. In contrast, other refractories, such as fused zirconia corundum bricks, have better performance but higher price.

IV. Physical properties

The volume expansion rate of silicon brick is relatively large, and the total volume expansion rate is about 1.26% when the temperature reaches 1450℃. This expansion characteristic helps to ensure the structural strength and air tightness of masonry.

The thermal conductivity of silicon brick is small, which can effectively reduce heat loss and improve energy utilization efficiency in high temperature environment.

V. Application site

In the melting pool of glass kiln, silica brick is mainly used in parts that are not in direct contact with molten glass, such as breast wall. These parts are mainly washed by alkali steam and batch, and silicon bricks can effectively resist these erosion.

Although fused zirconia corundum bricks or corundum bricks are usually used for the parts in direct contact with the molten glass, silicon bricks can also be used as ideal refractories in some areas with low temperature (such as cooling parts).

To sum up, the special function of silica brick in the melting pool of glass kiln is mainly reflected in its good corrosion resistance, high temperature stability, economy and physical properties. These characteristics make it an indispensable refractory in the melting pool of glass kiln.