Nano Al2O3 film encapsulated carbon-aluminum spinelle refractory castable and preparation method thereof

Abstract

The invention relates to a carbon-aluminum spinel refractory castable material wrapped up by a nano AL2O3 film and a preparation method thereof. The preparation method of the carbon containing castable material firstly puts the mixture of hydrated alumina, carbon powders and water in a high speed impact mixing-stirring mill for coating processing treatment, the materials impact and collide with each other after high-speed impact treatment, thus forming a composite sol suspension liquid of carbon and aluminum hydroxide and causing the aluminum hydroxide to be strongly absorbed on the surface of the carbon, therefore, the manufacture technology for coating carbon powders by using aluminum hydroxide is realized, then the composite sol suspension liquid is directly added to the mixed materials for preparing alumina gel coatings by controlling the conversion process from the aluminum hydroxide to the gel, and hence the whole-covered, crack-free and high-strength compact alumina wrapping layer is formed; and during the mixing and stirring process of the castable material, magnesium hydroxide sols are generated by the hydration reaction of magnesia powders and mixed water in matrix powders, then the nanostructure matrix of carbon-aluminum-spinel is generated by the in-situ synthesized reaction of the magnesium hydroxide sol and aluminum hydroxide sol suspension liquid, and finally the carbon-aluminum refractory castable material is prepared.

Description

[technical field] [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a carbon-aluminum spinel refractory castable which is wrapped with a nano-alumina film in an integral ladle for secondary refining of steelmaking and a preparation method thereof. [Background technique] [0002] With the increase of clean steel output, the application of secondary refining technology is becoming more and more common. In order to keep up with the development of clean steel, secondary refining technology has been developed rapidly. The LF refining method outside the furnace is a refining method that is widely used at home and abroad at present. The lining material of the ladle is made of magnesia-carbon bricks or aluminum-magnesia-carbon bricks, which is a relatively common form of refining ladles. Magnesia-carbon bricks using phosphorus-containing flake graphite are a kind of refractory material with excellent performance and are widely ...

AI Technical Summary

Problems solved by technology

However, in recent years, some problems have arisen in the use of magnesia-carbon bricks in the steelmaking process: the high thermal conductivity of phosphorus flake graphite causes the heat insulation effect to decrease, resulting in an increase in heat loss rate, resulting in deformation of the ladle furnace shell and a reduction in service life; Carbon in magnesia-carbon bricks will enter molten steel and cause carbonization of molten steel, especially after the secondary refining of molten steel, which will seriously affect the quality of molten steel. Therefore, the steel industry strongly requires reducing the carbon content in magnesia-carbon bricks. For this reason, researchers are working on Focus on the development of new magnesia carbon bricks with a carbon content of less than 5%

However, in the production and application of carbon-containing castables, there are still a series of problems, such as: the problem of poor wettability and dispersibility of carbon; the selection of carbon source and efficient antioxidant; the problem of oxidation at high temperature; the problem of oxidation The relationship between carbon and carbon is thermodynamically unstable, resulting in oxidation-reduction reactions that lead to deterioration of the organizational structure; problems such as the hydrophilicity, rheology, and water consumption of carbon have become restrictions on the further development of carbon-containing castables. and application of major problems

Therefore, until now, carbon-containing castables have not been industrialized and used in secondary refining, so how to solve these problems and develop nano-AL 2 o 3 Film-wrapped carbon-aluminum spinel refractory castable is a key issue in the development of secondary refining technology for steelmaking

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