What kind of refractory bricks are used for lining glass furnaces?

Glass melting furnace is the core equipment of glass production, and its lining material directly determines the life of the furnace and the quality of glass. Different types of refractory bricks are required for different parts due to different working environments.

1.Silica bricks – the traditional choice for high temperature areas

Silica bricks are commonly used materials for the upper structure of glass melting furnaces (such as the furnace roof).

Its main component is silicon dioxide, which has the characteristics of high load softening temperature and good high temperature volume stability. These characteristics also enable it to withstand the erosion of high-temperature airflow for a long time.

Specifically, silica bricks will form a quartz crystal structure at high temperatures and have strong creep resistance. Therefore, it is suitable for areas with small temperature fluctuations but consistently high temperatures.

However, silica bricks have weak resistance to alkaline slag corrosion. Therefore, it is not suitable for areas that come into direct contact with molten glass.

2.Magnesia refractory bricks – core material for alkali corrosion resistance

The areas at the bottom of the furnace that are in direct contact with the molten glass (such as the walls of the melting pool) need to rely on magnesia refractory bricks.

This type of brick has magnesium oxide as its main component. With its high melting point and excellent resistance to alkaline corrosion, it becomes the key to resisting the corrosion of alkaline oxides in molten glass.

Magnesia refractory bricks can be divided into magnesia-chrome bricks, magnesia-alumina bricks, etc. according to different bonding phases.

Among them, magnesia-chrome bricks have better thermal shock resistance. However, due to environmental issues, it has been gradually replaced by chrome-free magnesia bricks. Magnesia-alumina bricks improve thermal shock stability by adding alumina and are suitable for areas with large temperature changes.

Therefore, the selection should be based on the specific working conditions of the furnace and the environmental protection requirements.

3.Zirconium corundum bricks – key configuration of high-performance furnaces

For areas with more demanding conditions (such as flow holes and feeding ports), zirconium corundum bricks are a better solution.

This type of brick is composed of alumina, zirconium oxide and a small amount of silica. The zirconium oxide content determines its corrosion resistance. Zirconia forms a dense baddeleyite phase at high temperatures, which can effectively resist the penetration of molten glass and alkali slag.

Specifically, zirconium corundum bricks are not only resistant to high temperatures and corrosion, but also have better thermal shock stability than magnesium bricks. Therefore, it is suitable for areas with severe temperature fluctuations or severe mechanical erosion.

In short, when choosing a suitable refractory brick supplier, we need to focus on three points. First, its ability to control material purity. Second, its production process stability. Third, its customized service capabilities. Only in this way can we ensure that the lining material is precisely matched to the kiln operating conditions, thereby extending the furnace life and reducing overall costs.