Silica bricks for coke ovens refer to siliceous refractory products with tridymite as the main crystal phase, which are used to build coke ovens. The following is a detailed introduction to silica bricks for coke ovens:
I. Main raw materials and ingredients
Silica bricks for coke ovens are mainly made of high-purity silica (SiO₂) after careful processing, and the SiO₂ content is generally above 94%. Its main mineral phases are tridymite and cristobalite. In the production process, quartz sand and refractory clay are also selected as auxiliary raw materials to ensure the quality and performance of silica bricks.
II. Production process
The production process of silica bricks for coke ovens usually includes the following steps:
Raw material preparation: Screening, crushing, grinding and other treatments of raw materials such as silica, quartz sand and refractory clay to ensure that their particle size meets the requirements.
Mixing: Put the treated raw materials into a mixer, add a certain proportion of water, and stir to fully mix them to form a certain bonding force.
Molding: The mixed materials are molded through a mold. Common molding methods include pressure molding, extrusion molding and vibration molding.
Baking: Place the formed silica bricks in a special oven for initial baking to evaporate residual moisture and organic matter, so that the shape of the silica bricks remains stable.
Sintering: Place the baked silica bricks in a high-temperature kiln for heating, so that the silica and quartz sand in them react chemically to form a more stable silicate structure, thereby improving the thermal shock resistance and corrosion resistance of the silica bricks.
III. Main features
High refractoriness: The refractoriness of silica bricks is generally above 1650°C, and some are even as high as 1700°C, which can withstand the high temperature operating conditions of the coke oven, usually above 1000°C.
Excellent acid and alkali resistance: Silica bricks have good resistance to acidic and neutral molten substances.
Higher strength: Silica bricks can still maintain good mechanical strength at high temperatures and are not easy to deform or crack.
Thermal shock stability: Silica bricks have a strong adaptability to temperature changes and are not easy to crack in an environment with rapid temperature changes.
Thermal conductivity: Silica bricks have good thermal conductivity, which helps to evenly distribute heat in the furnace and improve the working efficiency of the coke oven.
IV. Application Scope
Silica bricks for coke ovens are mainly used in the furnace walls, furnace roofs and other parts of coke ovens to play a role in heat preservation and fire resistance. It is the main material that constitutes the basic parts of coke ovens (such as regenerator walls, ramps, combustion chambers, carbonization chambers, etc.), accounting for 60%~70% of the total refractory bricks. In addition, silica bricks are also widely used in high-temperature furnaces, insulation layers, refractory materials in industrial furnaces, etc.
With the rapid development of the global steel industry, the demand for coke continues to grow, which in turn promotes the prosperity of the silica brick market for coke ovens. It is expected that the global silica brick market for coke ovens will continue to grow in the next few years. On the one hand, the demand for silica bricks in traditional industrial fields such as steel and glass will continue to increase; on the other hand, with the rapid development of emerging industries such as new energy and new materials, the application field of silica bricks for coke ovens will be further expanded.
As a key material in the coke production industry, silica bricks for coke ovens have the characteristics of high refractoriness, excellent acid and alkali resistance, high strength, thermal shock stability and good thermal conductivity. It plays an important role in the construction of coke ovens, ensuring the durability and production efficiency of the furnace body. At the same time, with the development of the global economy and the optimization and upgrading of the industrial structure, the market for silica bricks for coke ovens will usher in a broader development prospect.
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