Question

\(\ldots\ldots\ldots\ldots\ldots\) refractories are used in tank of continuous glass melting furnace.

• A. Silica
• B. Magnesite
• C. Dolomite
• D. Electrocast AZS

Hint:

Electrocast AZS refractories are commonly used in glass tank furnaces because they resist corrosion by molten glass.

Answer 1

The Correct Option is D

A continuous glass melting furnace operates for long periods at very high temperature. The tank of the furnace remains in contact with molten glass. Therefore, the refractory used in the tank must have: \[ \text{high corrosion resistance,} \] \[ \text{low glass contamination,} \] \[ \text{high refractoriness,} \] and \[ \text{good resistance to molten glass attack.} \] Electrocast AZS refractories are widely used in glass melting furnace tanks. AZS stands for: \[ Al_2O_3-ZrO_2-SiO_2. \] These refractories contain alumina, zirconia, and silica. They are produced by electrofusion or electrocasting. Because of their dense structure and high resistance to molten glass corrosion, they are suitable for glass tank furnaces. Silica is used in some furnace superstructures but is not the best choice for tank contact with molten glass. Magnesite and dolomite are basic refractories and are not suitable for glass tank service. Therefore, the refractory used in tank of continuous glass melting furnace is: \[ \text{Electrocast AZS}. \]