A low-carbon magnesia-carbon brick with non-oxide reinforced and toughened structure and its preparation method

Abstract

The invention relates to a low-carbonmagnesia carbon brick with a non-oxidereinforcing and toughening structure and a preparation method of the low-carbonmagnesia carbon brick. The low-carbonmagnesia carbon brick is prepared from raw materials in parts by weight as follows: 75-95 parts of fused magnesia, 5-20 parts of Si3N4 powder, 0-5 parts of metal aluminum powder and 3-5 parts of phenolic resin. The preparation method comprises steps as follows: components of the raw materials are weighed in proportion, raw materials whose granularity is smaller than or equal to 0.088 mm are premixed for 2-5 minutes, and premix is obtained; raw materials whose granularity is larger than 0.088 mm are stirred for 2-6 minutes, a phenolic resin binder is added and stirred for 1-5 minutes, the premix is added and stirred for 3-10 minutes, the mixture is pressed and formed under the pressure of 50-250 MPa, a product is subjected to heat treatment in a dry kiln at the temperature ranging from 100 DEG C to 300 DEG C, the content of carbon in prepared materials can be reduced to 3%, recarburizationof the magnesia carbon brick to molten steel is effectively prevented, meanwhile, a flaky or fibrousnon-oxidebonding phase is generated in situ in a substrate under the use condition, the material structure is improved, the reinforcing and toughening functions are realized, the thermal shock resistance and the slag corrosion resistance of material are improved while the carbon content is reduced, and the clean steel smelting condition is met.

Description

technical field [0001] The invention relates to the technical field of refractory materials, in particular to a low-carbon magnesia-carbon brick with a non-oxide reinforced and toughened structure and a preparation method thereof. Background technique [0002] Traditional magnesia carbon bricks, with a carbon content between 10% and 20%, have always been the main refractory material for ladle working linings due to their good high temperature performance and excellent slag resistance. With the development of clean steel smelting technology, traditional magnesia-carbon bricks are mainly limited by two aspects: 1. Magnesia-carbon bricks have a large thermal conductivity, and the direct heat loss during use is high, which reduces the temperature of molten steel. 2. During the use of magnesia-carbon bricks, it is easy to add carbon to molten steel, which has a particularly serious impact on the smelting of low-carbon steel and ultra-low carbon steel. Therefore, under the premis...

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Problems solved by technology

With the development of clean steel smelting technology, traditional magnesia-carbon bricks are mainly limited by two aspects: 1. Magnesia-carbon bricks have a large thermal conductivity, and the direct heat loss during use is high, reducing the temperature of molten steel

2. During the use of magnesia-carbon bricks, it is easy to add carbon to molten steel, which has a particularly serious impact on smelting low-carbon steel and ultra-low carbon steel.

[0006] Due to the previous low-carbon magnesia-carbon bricks, or adding nano-scale oxides or non-oxides, or introducing modified expanded graphite to reduce the carbon content in magnesia-carbon bricks to improve the performance of magnesia-carbon bricks, but the two methods prepared The cost of low-carbon magnesia-carbon bricks is relatively high, and it is not easy to realize industrial production

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