Refractory materials are the main components of glass melting furnaces, which have a decisive impact on glass quality, energy consumption and product costs. The future of glass melting technology depends to a certain extent on the progress of refractory manufacturing technology and the improvement of product quality.
The refractories commonly used in glass melting furnaces are mainly divided into four categories: fused casting refractories, sintered refractories, amorphous refractories and thermal insulation refractories. Each type of material contains several types. The chemical composition, physical properties, size error and appearance type of refractory materials should meet the national standards or industry standards, and the latest revised version should be selected, otherwise it shall not be shipped.
Silica bricks are used more in glass melting furnaces, and the main component is silicon dioxide (SiO2). The silica bricks used in the glass melting furnace require a SiO2 content of more than 94%, a maximum use temperature of about 1600~1650 °C, and a density of 1.8~1.95g/cm3. The apparent porosity is required to be less than 22%, and the larger the porosity, the worse the quality of the silica brick. Most of the appearance of silica brick is white crystal, microscopic composition is the crystallization of scale quartz, because the silica brick at high temperature to occur crystallization transformation, volume expansion, especially at 180 ~ 270 °C and 573 °C or so, the crystallization transformation is more intense, so in the process of baking kiln and cold repair to adapt to the crystallization transformation of silica brick and take appropriate measures such as elastic tie strip.
The main components of clay bricks for glass kiln are Al2O3 and SiO2, the content of Al2O3 is between 30%~45%, SiO3 is between 51%~66%, the density is 1.7~2.4g/cm3, the apparent porosity is 12%~21%, and the maximum service temperature is 1350~1500 °C. In the glass industry, clay bricks are used to build the bottom of a kiln pool. The walls of the working section and the passage, the walls of the regenerator, the ballast and the lower lattice bricks and the flue. As the temperature increases, the volume of clay bricks also expands. When the temperature exceeds 1450°C, the volume shrinks again.
The main component of mullite bricks is Al2O3, and its content is about 75%, because it is mainly mullite crystals, so it is called mullite bricks. The density is 2.7-3 2g/cm3, the opening porosity is 1%-12%, and the maximum service temperature is 1500~1700 °C. Sintered mullite is mainly used for masonry regenerator walls.