Refractory materials are an indispensable protective lining for the construction of many thermal equipment. Today I will introduce the application of silica bricks in refractory materials in glass kilns. Silica bricks for glass kilns have many advantages and are mainly used for glass domes and chest walls. , Wall hanging, small stove top structure.
Silica brick for glass melting furnace is an acid refractory material, mainly composed of tritium, calcite and a small amount of quartz and glass phase. The raw material is natural silica sand, and the SiO2 content should be greater than 96%. The higher the SiO2 content in silica sand, the higher the temperature resistance of silica bricks. Silica bricks are used for the roof and superstructure of the molten glass pool and for thermal repair.
Introduction of silica brick for glass melting furnace
Silica bricks for glass melting furnaces refer to silicon refractory products used in the high temperature part of the glass furnace (not in contact with molten glass). Glass kiln silica brick has the characteristics of high temperature resistance, stable volume, no pollution to glass liquid, chemical corrosion resistance, small bulk density, etc., which can reduce the weight of the furnace body. The tank kiln is a complex masonry made of various refractory materials. Most of its vaults use high-quality silica bricks for glass kilns, chest walls and small furnaces. Some glass kiln recycled domes and checker bricks also use silica bricks.
Silica brick for glass melting furnace
1. The volume is stable at high temperature, and the furnace body does not change due to temperature fluctuations. Because of the high-load softening temperature and low creep rate of silica bricks, the glass furnace can prevent the furnace body from deforming at 1600°C, and the structure is stable.
2. The glass liquid is pollution-free. The main component of silica bricks is silicon dioxide. If used, if there is a drop or drop on the surface, the silica brick for glass melting furnace will not affect the quality of the molten glass.
3. Resistance to chemical attacks. The superstructure silica brick is corroded by R2O gas in the glass frit, and a smooth metamorphic layer is formed on the surface, which reduces the corrosion rate and plays a protective role.
4 shown. The volume density is small, which can reduce the weight of the furnace body.
Manufacturing process of silica brick for glass melting furnace
1. Raw material selection
Quartzite with 98% SiO2 content is used as raw material, and the soil is washed with water. After crushing, 3mm, 2mm, 1mm multilayer screens are used, and the screen materials are stored separately.
2. Formed shape
Powders of different particle sizes are mixed with mineralizers, binders, and water in a mixer, and silica bricks for glass kilns are formed by a molding machine. For complex shapes or large products, vibration molding machines, air hammers or manual molding machines can be used. After each piece of silica brick is formed, the size and shape should be checked, and qualified bricks should be dried.
3. Dry
Large refractory bricks and hand-formed refractory bricks are suitable for indoor drying. The initial temperature does not exceed 60 degrees Celsius. For tiles above 40 kg, dry in the air for more than 48 hours. Check the dry refractory bricks again, focusing on surface cracks and internal cracks. After drying, the residual moisture of the silica brick does not exceed 1%, and the large silica brick does not exceed 0.5%. Silica bricks for glass melting furnaces are burned in tunnel kilns, downwind kilns and shuttle kilns. Downdraft kilns or shuttle kilns are declared to burn large refractory bricks and cover small furnace bricks. At 1380-1450 degrees Celsius, the high combustion temperature depends on the conversion performance of the raw materials and the quality requirements of the product
4. Products
The attention phase of product cooling is below 600 degrees Celsius. Due to the change of crystal morphology, the volume shrinks rapidly and cracks are prone to occur. The cooling rate should be controlled. The cooled product should be selected piece by piece. Large vault tiles should be boxed according to user requirements according to dimensional tolerances, and marked on the glass melting furnace. Silica refractory bricks for important parts of the glass industry need to be machined, prefabricated, and numbered. The processed bricks should be checked again before pre-laying.
5. Use
The smelting furnace using silica bricks should be stored in a waterproof warehouse and can be used after being damp at a temperature below 100 degrees Celsius. Water-containing silica bricks will affect the strength after freezing, and will be retested after drying. The masonry shall be equipped with expansion joints according to the expansion rate provided by the manufacturer. The temperature-time curve of the oven or regular use should be reasonably prepared, and the expansion should be strictly controlled within 600 degrees Celsius. The quality of mud used for masonry should be the same as that of silica bricks. Sometimes the damage of the brick is due to the first corrosion of the brick joints and the generation of alkali vapor.
How to reduce the consumption of silica bricks in glass furnaces
Due to the high-load softening temperature, light weight and low price advantages of quartz bricks, in order to increase the melting temperature and prolong the overall life of the kiln, the small furnace mouth and chest wall are replaced with bricks, and some domes or parts are replaced with other materials. Can reduce the consumption ratio of silica bricks.
How to choose silica brick suitable for glass kiln
1. Usually the ratio is 50%-75%. High-grade silica brick products can exceed 50% of calcite due to less molten impurities. The remaining quartz does not exceed 3%.
2. Calcium oxide brick, the ratio of block stone to tritium is greater than 1
3. Scale-type silica brick, the ratio of calcite to tritium is equal to or less than 1
4. The proportional silica brick has a small expansion rate, which is beneficial to maintain the stability of the kiln body in the kiln body. During use, the tridymite in the hot end brick can gradually be converted into calcite, and the low melting point material can migrate to the cold end.
Wechat Us 
