Application of Zircon Brick in the E Glass Furnace

E glass, also known as electric glass, is a type of aluminum borosilicate glass used to produce glass fibers for reinforced plastics designed for applications requiring high electrical resistivity. Zircon brick is a preferred choice in the demanding areas of the E glass furnace due to its good corrosion resistance. 

The drawing technology of the E glass furnace is the most advanced technology for producing glass fiber. A furnace for melting and refining E glass comprises a melting and refining tank for melting and refining the glass batch materials into glass and a forehearth, downstream of the tank, for further refining the glass and delivering the glass to fiberizing means. The melting and refining tank of a E glass furnace is 2-3 times as long as other glass furnaces, so the glass stays for for a longer time. 

 

The melting temperature of E glass is above 1540℃ and its softening temperature is over 840℃. Its crystallization temperature is between 1080-1110℃. It has good water resistance, good electrical insulation and high mechanical strength. The glass for producing E glass fiber is required to have no stone and bubble. Besides, the E glass contains MgO, which accelerates the corrosion of refractories. So there is a need for refractories with excellent physical and chemical properties, good high temperature resistance, high thermal shock resistance and corrosion resistance to E glass. 

 

In the doghouse, though the temperature is lower, the mechanical erosion and the physical and chemical reaction are severe. In the throat, as the temperature is higher and the flowing rate of the glass liquid is rapid, the corrosion is severe. In those demanding areas, thickened dense zircon brick is used. 

 

The E glass furnace sometimes adopts a throat structure with a block brick. The block brick is always made up of porous zircon brick and wrapped with platinum alloy. The channel of the forming zone also adopts the zircon brick. 

 

At the bottom of the tank, zircon brick is also used in the bubble block and electrode block, but it is better to be used under 1370℃.