Nano-carbon low-carbon magnesia carbon brick for ladle slag line and preparation method

Abstract

The invention discloses a nano-carbon low-carbon magnesia-carbon brick for ladle slag lines and a preparation method, wherein the magnesia-carbon brick comprises fused magnesia with five particle sizes, dispersible nano-carbon and an antioxidant, and through coating of nano-carbon films on the surfaces of fused magnesia particles with different particle sizes and application of the dispersible nano-carbon, the nano-carbon low-carbon magnesia-carbon brick can be used for ladle slag lines. By utilizing the characteristics that the nano carbon film and the dispersible nano carbon are mainly amorphous carbon, contain a small amount of graphite young crystals, can be infiltrated by a solvent and the like, infiltration and adsorption of the nano carbon film and the dispersible nano carbon to anorganic binding agent are improved, and uniform dispersion of the nano carbon in the magnesia carbon brick is realized; in addition, the size of carbon particles in the magnesia carbon brick is greatly reduced by controlling the sizes of the nanocarbon film and the dispersible nanocarbon with the thickness of 20-200 nanometers, the contact frequency of a refractory raw material of the magnesia carbon brick and the carbon particles is remarkably improved, the performance of the carbon particles is exerted under the condition of low carbon content, and the anti-erosion permeability of the magnesia carbon brick is improved.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a nano-carbon low-carbon magnesia-carbon brick for a ladle slag line and a preparation method thereof. Background technique [0002] Magnesia-carbon bricks are non-burning carbon composite refractories made of magnesia and high-melting graphite carbon materials that are difficult to be infiltrated by slag as the main raw materials, adding various non-oxide additives and carbon binders. Due to the small thermal expansion coefficient of graphite, high thermal conductivity, high melting point, and not easily wetted by slag, magnesia carbon bricks have excellent characteristics such as high temperature resistance, strong slag resistance, high thermal shock resistance and low high temperature creep. And it is widely used in steelmaking process. Due to the high total carbon content of conventional MgO-C bricks, about 10-20%, the commonly used carbon materials ...

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Problems solved by technology

The prepared metal composite low-carbon magnesia-carbon brick for ladle slag line has a bulk density of ≥2.96g / cm 3 , apparent porosity ≤ 6%, normal temperature compressive strength ≥ 45MPa, 1400 ℃ buried carbon high temperature flexural strength ≥ 25Mpa, carbon content ≤ 6%, MgO content ≥ 80%, thermal shock resistance adopts 1100 ℃, air cooling once The residual strength retention rate measured by the air quenching method is 70-80% (the residual strength retention rate of commonly used magnesia-carbon bricks is 50-60%); but due to the high cost of metal powder and antioxidants, it has not been widely used at present

Chinese patent "Ma Beiyue, Ren Xinming, Su Chang, etc., a nano-carbon reinforced low-carbon magnesia-carbon brick and its preparation method, patent application number: 201810613284.X" discloses a low-carbon nano-carbon content of 2 to 4%. The magnesia-carbon brick and its preparation method comprise the following mass percentages of various raw materials: 90%-95% of raw magnesia, 2-4% of nano-carbon, 2%-3% of antioxidant, and 4% of binder; wherein, nano-carbon The mass percentage of carbon in coke is ≥98%, which is nano-graphite oxide sheet, carbon nanotube, carbon black, activated carbon, coke or any mixture of two of them; obviously it is very difficult for the mass percentage of carbon in coke to be ≥98%, and in addition , the patent does not introduce how to disperse the nano-carbon that is easy to agglomerate in the magnesia-carbon brick, and it is difficult to implement it industrially

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