Composite brick and preparation method thereof

Abstract

The invention provides a composite brick and a preparation method thereof. The composite brick comprises a hot end aluminum brick layer and a cold end hollow sphere brick layer combined therewith, wherein the hot end aluminum brick layer is formed by high aluminum clinker or mullite, binding clay, silicon micropowder and phosphoric acid; and the cold end hollow sphere brick layer is formed by aluminum hollow spheres or mullite hollow spheres, high aluminum clinker or mullite, binding clay, silicon micropowder and phosphoric acid. Compared with the existing high aluminum brick or light brick, the hot end of the composite brick in contact with a working layer is the aluminum brick layer, thus having favorable high-temperature strength and heat stability; and the cold end is a hollow sphere brick of which the main raw materials are aluminum hollow spheres or mullite hollow spheres combined with high aluminum clinker or mullite, so that the hollow sphere brick is less prone to shrink at high temperature while reducing the heat conductivity coefficient. The composite brick obtained by combining the aluminum brick and the hollow sphere brick has the advantages of low heat conductivity coefficient, less temperature drop, low energy consumption, no shrinkage at high temperature and the like, and prolongs the service life.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a composite brick and a preparation method thereof. Background technique [0002] The ladle is an intermediate container connecting steelmaking and continuous casting, and almost all refining processes outside the furnace must be completed in the ladle. The main function of the ladle is to transfer molten steel and serve as a refining container. The molten steel alloys the molten steel in the ladle, which can adjust the temperature and uniform composition of the molten steel, and promote the floating of inclusions in the molten steel. The quality of the ladle working condition not only affects the quality of molten steel in the previous steelmaking process, the life of the furnace lining, and the prelude to production; and manufacturing costs. [0003] The temperature of the molten steel in the ladle is generally 1530°C to 1620°C, the storage time for t...

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Problems solved by technology

[0005] The normal temperature strength of high-alumina bricks is as high as 30-50MPa, and the load is soft at 1450°C. The refractoriness fully meets the requirements for the use of the permanent layer of the ladle, but its thermal conductivity is 1.5W / m K. Under high temperature conditions, the thermal conductivity will reach 2W / m K above will lead to increased heat dissipation and poor heat preservation effect, and the high-alumina bricks mainly use first-grade high-alumina clinker as raw material, the firing temperature is 1420°C, the firing cost is high, and the product cost is high

[0006] The density of lightweight bricks is 1.2g / cm 3 The normal temperature strength is as high as 5-7MPa, and the thermal conductivity is 0.5W / m·K at 350°C. However, under high temperature conditions, the thermal conductivity of lightweight bricks will increase, and at 1350°C, they will shrink severely. The volume also increases, causing its thermal conductivity to reach about 1.0W / m·K, which not only reduces the thermal insulation effect of lightweight bricks, but also causes safety hazards in the use of ladles due to high temperature shrinkage, and the service life is low. At the same time, lightweight bricks The production process is also very complicated, and its cost is 2 times higher than that of high alumina bricks

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