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Silica Bricks for Glass Furnace

  • Silica Bricks for Glass Furnace

1. Samll bulk density

2. Resistance to chemical attack

3. High temperature volume stable

4. No pollution to the glass liquid.
Silica Bricks for Glass Furnaces Introduction
 
Silica bricks for glass furnace refers to the silicon refractory product used in the high temperature part of the masonry glass kiln (not in contact with the glass liquid).Glass kiln silica brick has high temperature and volume stability, no pollution to glass liquid, chemical corrosion resistance, small bulk density, and can reduce the weight of furnace body.The pool kiln is a complex masonry, the masonry made of various refractory materials. Its vaults mostly use high quality silica bricks for glass kiln, chest walls, and small furnaces.Some glass kiln regenerator domes and checkered bricks also use silica bricks.
 
Silica Bricks for Glass Furnaces Defination
 
Silica bricks for glass melting furnaces is a kind of acid refractory mainly made from tridymite, cristobalite and a small amount of residual quartz as well as glass phase. The raw refractory material is natural silica sand whose SiO2 content should be more than 96%. The higher SiO2 content in silica sand, the higher temperature silica bricks resist. Silica bricks are used in the roof and superstructure of glass melting tanks as well as for hot repairs.
 
Silica bricks for glass melting furnaces is a kind of acid refractory mainly made from tridymite, cristobalite and a small amount of residual quartz as well as glass phase. The raw refractory material is natural silica sand whose SiO2 content should be more than 96%. The higher SiO2 content in silica sand, the higher temperature silica bricks resist. Silica bricks are used in the roof and superstructure of glass melting tanks as well as for hot repairs.
 
Silica Bricks for Glass Melting Furnaces Feature
 
1.The high temperature volume is stable, and the furnace body does not change due to the temperature fluctuation surface. Because the silicon brick has a high load softening temperature and a small creep rate, the glass kiln can keep the furnace body from deforming at 1600 ° C, and the structure is stable.
 
2.No pollution to the glass liquid. The main component of silica brick is SiO2. If it is used, if there is any drop or surface droplet, silica bricks for glass melting furnace  will not affect the quality of the glass liquid.
 
3.Resistance to chemical attack. The superstructure silicon brick is eroded by R2O gas in the glass batch, and a smooth metamorphic layer is formed on the surface, which makes the erosion speed lower and protects.
 
4. The bulk density is small, which can reduce the weight of the furnace body.
 
Silica Bricks for Glass Furnaces Manufacturing Process
 
1. Selection Silica Bricks of Raw Materials
 
The quartzite having a SiO2 content of 98% is selected as a raw material, the soil is removed by washing with water. After pulverization, 3mm, 2mm, 1mm multi-layer sieves are used, the sieve materials are stored separately.
 
2. Silica Bricks of Forming Shape
 
Powders of various particle sizes are mixed with mineralizers, binders and water in a mixer, and silica bricks for glass kiln are formed by forming machinery. For complex shapes or large products, vibration molding machines, wind hammers or manual molding can be used.Each silica brick after molding is inspected for size and shape, and the qualified bricks are dried.
 
3. Silica Refractory BricksDrying
 
Large refractory bricks and hand-formed refractory bricks are suitable for drying in a chamber drier. The initial temperature does not exceed 60 degree Celsius. Tiles of 40 kg or more should be dried in air for more than 48 h. The dried refractory bricks are inspected again, with the focus on checking for surface cracks and internal cracks. The residual moisture of the silica brick after drying is not more than 1%, and the large silica brick is not more than 0.5%. Silica refractory brick for glass melting furnace are fired in tunnel kiln, downwind kiln or shuttle kiln. The downdraft kiln or shuttle kiln is declared to be fired into large firebricks and covered with small furnace bricks. The highest firing temperature is based on the conversion properties of the raw materials and the quality requirements of the products at 1380-1450 degree Celsius
 
4.Silica Bricks Products
 
The dangerous stage of product cooling is below 600 degree Celsius. Due to the crystal form change, the volume shrinks rapidly, and cracks are easily generated, and the cooling rate should be controlled. The cooled product is subjected to block-by-block selection. Large vaulted bricks should be binned according to the user's requirements according to the dimensional tolerances and marked on the glass melting furnace .Silica refractory bricks for glass industry in important parts need to be machined, pre-built, and numbered. The processed brick should be inspected again before pre-laying.
 
4. Silica Bricks Using
 
Melting furnace used silica bricks should be stored in a waterproof warehouse and can be used after being wetted at a temperature below 100 degree Celsius. The water-containing silica fire bricks will affect the strength after freezing, and will be retested after drying. Masonry shall be provided with expansion joints at the expansion rate provided by the manufacturer. The temperature-time curve of the oven or periodic use should be reasonably formulated, and the expansion should be strictly controlled before 600 degree Celsius. The quality of the mud used in bricklaying should be compatible with the silica  bricks. Sometimes the damage of the brick is due to the fact that the brick joint is firstly eroded to cause alkali vapor.
 
Silica Bricks for Glass Furnaces Specification
 
Item Unit Index
SiO2                   > % 96
Fe2O3                   ≤ % 0.6
Al2O3                   ≤ % 0.30
CaO                    ≤ % 2-3
R2O                     ≤ % 0.08
Melt Index [Al2O3+2R2O]   ≤ % 0.5
Refractoriness Under Load (0.2MPa)≥ 1685
 Refractoriness ≥ 1710
Apparent Porosity ≤ % 20
Cold Crushing Strength   ≥ MPa 40
True Bulk Density      g/cm3 2.33
 
How to Reduce the Consumption of Silica Bricks in Glass Furnaces
 
Due to the high load-softening temperature, light weight and low price advantage of silica bricks,in order to increase the melting temperature and extend the overall life of the kiln, the small furnace mouth and the chest wall are changed to cast bricks, and some of the domes or parts thereof are changed to other materials. The consumption ratio of silica bricks may be reduce.
 
How to Choose the Suitable Silica Brick for Glass Kiln
 
1. Generally, the scale quartz is 50%-75%. High-grade silica brick products can exceed 50% of cristobalite due to less fluxing impurities. Residual quartz is no more than 3%.
 
2. Square-scale silica brick, the ratio of cristobalite to tridymite is greater than 1
 
3. Scale-type silicon brick, the ratio of cristobalite to tridymite is equal to or less than 1
 
4. The scale-type silicon brick has a small expansion rate, which is beneficial to maintain the stability of the kiln during the kiln. In use, the scaly quartz in the hot end brick can be gradually converted into cristobalite, and the low melting material migrates to the cold end.
 
Why Choose Silica Bricks from Rongsheng Refractory Bricks Manufacturer
 
Rongsheng refractory company adhering to the “integrity ,innovation and hard work”business philosophy,the “people-oriented”as the cornerstone of enterprise development to pursuit of excellence as the core values of the enterprise,will create “Rongsheng Brand”as a corporate strategic objectives.Product types rich scientific management processes, improve customer information management system, timely,efficient, to proved satisfactory service to our customers. Rongsheng refractory bricks factory can provide competitive prices and excellent service. Consult with many professional engineers to deal with your problems. Choose us as your supplier, we will become your loyal partner and solve your problems, silica bricks produced by our company have been successfully applied in various high temperature glass melting furnace in industry at home and abroad.