In a glass melting kiln, the refractory brick used in the melting part of the pool wall has the following performance requirements:
1. High fire resistance
– The temperature of the melting part of the glass is usually very high, up to about 1600℃. Therefore, firebricks need to have a high refractoriness to ensure that they will not soften or melt at such high temperatures and can maintain the structural integrity of the pool wall. For example, fused zirconium corundum bricks have a high refractoriness and can withstand high temperatures at the melting part.
2. Good erosion resistance
– Liquid glass contains a variety of ingredients, such as alkali metal oxides, etc., which has a certain chemical erosion. The refractory brick needs to be able to resist the erosion of the glass liquid to prevent the chemical reaction between the components of the glass liquid and the refractory brick, so as to avoid the corrosion damage of the pool wall. Fused zirconium corundum brick contains zirconia component, which has good resistance to alkaline component erosion in glass liquid.
3. Excellent thermal shock resistance
– During the operation of the glass melting kiln, the wall of the melting part will experience frequent temperature changes. For example, when feeding, changing fire and other operations, the temperature will fluctuate. Refractory bricks need to have good thermal shock resistance and be able to withstand this rapid change in temperature without cracking or peeling.
4. Low porosity
– Low porosity of firebricks can reduce the possibility of glass liquid penetration into the brick body. If the porosity is high, the glass liquid is easy to penetrate the brick, resulting in the destruction of the brick structure, but also may pollute the glass liquid, affecting the quality of the glass.
5. Good mechanical strength
– To withstand the static pressure of liquid glass and the scouring force when flowing. Especially in the area where the convection of liquid glass is relatively strong, the firebrick of the pool wall needs to have sufficient mechanical strength to prevent damage by the erosion of liquid glass.
6. Chemical stability
– In addition to resisting the erosion of glass liquid, it is also necessary to maintain chemical stability when in contact with combustion gases, fluxes and other substances in the melting kiln to avoid chemical reactions that change their own properties or adversely affect the quality of the glass.
