Low-carbon magnesia carbon brick with magnesia impregnated by tar and asphalt as aggregate and preparation method thereof

Abstract

The invention discloses a Low-carbon magnesia carbon brick with magnesia impregnated by tar and asphalt as an aggregate and a preparation method thereof. The low-carbon magnesia carbon brick comprisesthe following components by weight: 45 to 55% of a magnesia aggregate impregnated by tar and asphalt, 35 to 45% of unimpregnated magnesia, 3 to 5% of graphite, 0.5 to 1.5% of high-temperature asphalt, 2 to 3% of an antioxidant and 2.5 to 3.5% of a binder. The preparation method comprises the following steps: 1) carrying out impregnating so as to obtain the magnesia aggregate impregnated by tar and asphalt; 2) weighing the components with the desired weight; 3) premixing unimpregnated magnesia powder, high-temperature asphalt and the antioxidant to obtain mixed powder; 4) subjecting the magnesia aggregate and the unimpregnated magnesia powder to dry mixing in a mixing and grinding machine, then successively adding the binder, graphite and the mixed powder, and carrying out mixing and grinding to form a mixture; and 5) carrying out briquetting, molding and heat treatment so as to obtain the low-carbon magnesia carbon brick with the magnesia impregnated by tar and asphalt as the aggregate. The low-carbon magnesia carbon brick has the advantages of good thermal shock resistance, good resistance to slag erosion and great high-temperature strength, and is significantly prolonged in service life.

Description

technical field [0001] The invention relates to a low-carbon magnesia-carbon brick, in particular to a low-carbon magnesia-carbon brick with magnesia soaked in tar and asphalt as an aggregate and a preparation method thereof. Background technique [0002] Due to its excellent thermal shock resistance and slag erosion resistance, magnesia carbon bricks are widely used in converters, electric furnaces, refining furnace linings and ladle slag lines. With the development of the iron and steel industry, the proportion of smelting low-carbon steel and clean steel is increasing. Ordinary magnesia-carbon bricks have exposed some problems such as carburization of molten steel, high heat loss, and consumption of a large amount of valuable graphite resources. Therefore, low The development and application of carbon-magnesia-carbon bricks have received extensive attention. [0003] As the carbon content decreases, the thermal conductivity of magnesia carbon bricks decreases, and its th...

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Problems solved by technology

In order to improve the thermal shock resistance and corrosion resistance of low-carbon magnesia-carbon bricks, refractory workers mainly take the following three measures: 1) Add antioxidants to magnesia-carbon bricks to prevent graphite from being oxidized. The impact is that the improvement of the material performance is limited, and the manufacturing cost is relatively high; 2) the carbon structure of the bonded carbon is improved by modifying the binder. The negative impact of this method is that the binder modification effect is poor and the manufacturing cost is high. Not suitable for industrial production

3) Adding nano-scale carbon sources, the negative impact of this method is that it is difficult for nano-carbon sources to disperse evenly in the matrix, which affects performance

However, when preparing the composite binder, this document simply mixed the powder of mesophase pitch and phenolic resin, and did not further prepare magnesia-carbon bricks, so it was impossible to measure its actual effect after it was applied to magnesia-carbon bricks.

At the same time, in the actual production of magnesia-carbon bricks, liquid phenolic resin is used, which has a high viscosity, and the dispersion effect of asphalt in it is poor, and will reduce the viscosity and bonding of the resin; while the asphalt is dispersed in liquid phenolic resin under heating. In the resin, it will cause the resin to solidify, reduce the viscosity and bonding of the resin, and affect the strength of the magnesia carbon brick

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