Fused AZS bricks are also called fused alumina-zirconium-silica bricks. Generally, fused AZS bricks are divided into three grades according to the zirconium content: 33%, 36%, and 41%. The zirconium corundum bricks used in the glass industry contain 50% to 70% AL2O3, 20% to 40% ZrO2, a density of 3.4 to 4.0c/cm3, and a maximum operating temperature of about 1700°C. Fused AZS bricks with a zirconium content of 33% and 36% are used to build the flame space breast wall of the kiln wall, the flame vent of the port, the flat grate of the port, the port stack, the tongue brick, etc. The zirconium content is 41 % fused AZS bricks are used to build pool wall corners, liquid holes and other parts where the glass liquid erodes the refractory materials more severely.

Fused alumina bricks also called fused corundum bricks mainly refer to fused a, β corundum and fused β corundum bricks. It is mainly composed of 92% to 94% AL2O3 corundum crystal phase, with a density of 2.9 to 3.05g/cm3 . The highest operating temperature is around 1700℃. Fused alumina has very good resistance to glass leakage and hardly pollutes the glass liquid. It is widely used in the working part tank wall, tank bottom, flow channel, working part forehearth tank wall, forehearth tank bottom, etc. of the glass melting furnace that are in contact with the glass liquid and are required to be free of refractory material contamination.

Pollution resistance of AZS series electro-cast bricks is not as good as that of alumina series electro-cast bricks. This is because the alumina electroformed bricks are very pure, more than 90% of which are Al2O3. Fused a-β-Al2O3 brick contains almost no glass phase and has less contamination of the glass liquid, this brick is widely used in the working pool and forehearth of soda-lime glass furnaces.

For fused alumina bricks, the viscosity of the nepheline metamorphic layer generated on its surface in the glass liquid is not as high as that of the nepheline metamorphic layer containing ZrO2. It is relatively easy to melt, so its corrosion resistance at high temperatures is not as good as that of fused AZS bricks. However, the greater the difference in viscosity between the debris flowing into the glass liquid and the glass liquid, the more difficult it is to dissolve and eliminate. The nepheline metamorphic layer of alumina bricks has a small viscosity and is easily soluble in the glass liquid, so the pollution to the glass liquid is small.