Fused cast low-leakage series are supposed to be a new AZS product for high-end market of glass furnaces. The main component of them is fused alumina-zirconia-silica, which contains 36% ZrO2 and a lower silicate phase (14%). It has very low leakage and quite strong resistance to alkaline attacks, carry-over and creep.
With the efforts in recent years, lots of Chinese enterprises already have been capable of commercial production of these products. The capability has gradually been developed and applied in glass industry.
Low-leakage series are widely used in shaped products for high-end glass furnaces, such as fields of optical glass, high alumina glass, TFT-LCD, borosilicate glass, etc. They can be used on the parts which have strict requirements for high temperature performance and glass phase leakage pollution, like crown of oxygen-fuel glass furnace, top spaces of refiner and doghouse crown etc.
The core of low-leakage series is low introduction of Na2O, which makes structure of refractory materials with an effect of lower glass phase. Traditional fused cast zircon-corundum refractory is composed of baddeleyite, corundum and sodium aluminosilicate glass phase. And glass phase is able to bring effects of fluxing, relaxation annealing stress, and transformation stress. Its existence sharply reduces the occurrence rate of cracks in materials and improves yield of refractory materials. However, the existence of glass phase completely weakens corrosion resistance of refractory. Especially in high temperature condition, the leakage of glass phase is a potential risk of polluting glass.
Physical and Chemical Indicators