Carbon-spinel magnesium fire-resistant castable wrapped with nano Al2O3 and MgO films and preparation method thereof

Abstract

The invention relates to carbon-spinel magnesium fire-resistant castable wrapped with nano Al2O3 and MgO films and a preparation method thereof; the carbon-containing castable is a coating material taking Al(OH)3 and Mg(OH)2 sol suspension as carbon powder; a high-speed impact stirring device is used for conducting coating technique processing treatment so as to cause the Al(OH)3 to be strongly adsorbed on the surface of carbon; the manufacturing technique of coating aluminum hydrate sol liquid on carbon is realized; the carbon-containing sol liquid is directly added into a mixture and generates hydration with reactive magnesium oxide powder in substrate powder and mixed water so as to prepare Al(OH)3 and Mg(OH)2 composite sol suspension which serves as the coating material of carbon and a ceramic binder of nano complex oxides of the carbon-containing castable; the transformation process from hydroxide sol to gel is controlled to prepare an aluminum oxide and magnesium oxide gel coating which is treated with synthesis in situ to form a carbon-containing nano structural substrate of nano secondary spinel and magnesium oxide and finally prepare the carbon-spinel magnesium fire-resistant castable.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a kind of nano Al 2 o 3 A carbon-spinel magnesia refractory castable wrapped in MgO film and a preparation method thereof. Background technique [0002] With the sharp increase in clean steel output, the application of secondary refining technology is becoming more and more common. In order to keep up with the pace of clean steel demand, secondary refining technology has been developed rapidly. Refractory materials keep up with the technological progress of the steel industry and provide Great progress has been made in providing the best service to the industry and satisfying the efficient operation of refining process equipment. In recent years, the main trend of the technical development of refractory materials is to continuously increase the use of integral refractory materials or unshaped refractory materials, especially the use of refractory castab...

AI Technical Summary

Problems solved by technology

The current actual situation is that the traditional resin-bonded magnesia-carbon brick masonry slag line is still widely used in the refining overall ladle slag line at home and abroad. The variety and quality of materials cannot meet the requirements for the use of the slag line, making it a key link in the overall pouring of the secondary refining ladle

At present, there are a series of serious problems in the refining ladle using magnesia-carbon bricks combined with organic resin to build the slag line: first, the use of magnesia-carbon bricks in the slag line cannot be poured as a whole, so that the advantages of the overall ladle cannot be fully utilized The second is that the service life of magnesia-carbon bricks used in the slag line is low, and the actual service life is between 25-40 heats, while the service life of the overall package bottom, package body and impact zone that are in direct contact with molten steel is 100- More than 120 heats, so the slag line is frequently shut down to replace the inner lining, which seriously affects the production of poured steel; the third is that the resin bonded magnesia carbon bricks for the ladle slag line and the bottom, body, and impact area of ​​the ladle are water-based There is a serious incompatibility between the combined castables, which is mainly reflected in the hydration of the magnesia-carbon bricks, so that it cannot be carried out simultaneously during the ladle baking process, and the actual operation is often to pour the bottom and the body first , and then the maintenance and baking of the castable, the masonry slag line is built, and it can be put into use after baking again, which brings considerable difficulties to the actual production operation. The new material required for refining is a key issue

Carbon has the advantages of not being easily wetted by molten steel and slag, low thermal expansion and high thermal conductivity, and will not soften after long-term use at high temperatures. However, there are still a series of problems with carbon in water-based castables , such as: the problem of poor wettability and dispersibility of carbon; the problem of oxidation at high temperature; Denaturation and water consumption have become major problems restricting the further development and application of carbon-containing castables

Until now, carbon-containing castables have not been mass-produced and practically used in steelmaking, so the research and development of carbon-containing castables has become a hot topic of great concern in the refractory industry at home and abroad.

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