Which refractory bricks are used in glass tanks that hold molten glass?

Refractory bricks used in glass tanks must withstand the highly corrosive environment of molten glass. Several specialized materials are employed for this purpose:

• Flux Blocks: These are highly siliceous, dense fireclay bricks specifically preferred for the sections of the tank in direct contact with molten glass.1
• Zircon and Zirconia: Refractories made of zircon are used for their resistance to glass corrosion and volume stability. Zirconia bricks are also utilized due to their lack of porosity and high resistance to chemical attack.21
• Alumina-Zirconia-Silica (AZS): This material is highly corrosion-resistant and does not contaminate the glass melt. It is cast into molds or directly into melting tanks and is commonly used to create tank blocks (also known as soldier or sidewall blocks).3
• Mullite and Fused Alumina: Prepared from kyanite, mullite bricks offer excellent durability, similar to fused alumina bricks, as both are chemically inert and resist glass penetration.1
• Silica: Super-duty silica bricks are specifically utilized in the superstructures of glass-melting furnaces.4