Slag line brick for steel ladle and preparation method

Abstract

The invention relates to a slag line brick for a steel ladle and a preparation method. The slag line brick for the steel ladle is prepared from, by weight, 10-40 parts of fused magnesite with the particle size greater than or equal to 3 mm but smaller than 5 mm, 5-30 parts of fused magnesite with the particle size greater than or equal to 1 mm but smaller than 3 mm, 10-20 parts of fused magnesite with the particle size smaller than 1 mm, 5-20 parts of magnesite-carbon waste brick fine powder, 12-16 parts of flaky graphite, 1-3 parts of bonding agent and 4 parts or less of additive. The slag line brick has the advantages that the problem that an existing slag line brick frequently produces a steamed bun shape in the using process is solved, the slag line brick for the steel ladle adopts phenolic resin having better wettability and moisture retention property, the pug temperature is strictly controlled, the phenomenon that mixed pug is dried too fast due to too high temperature is avoided, the adding amount of metal or alloy powder is appropriately controlled by increasing critical particle size, the graphite adding amount is increased, a heat stress is buffered by introducing a trace amount of additive, and the thermal shock resistance stability of the slag line brick is improved.

Description

technical field [0001] The invention belongs to the field of refractory materials, and in particular relates to a slag wire brick for a ladle and a preparation method thereof. Background technique [0002] Magnesia-carbon brick is a kind of high-quality refractory material. Because this kind of carbon-containing refractory product has the advantages of high refractoriness, good slag erosion resistance, strong thermal shock resistance and low high temperature creep, it is widely used in electric furnaces, converters and ladles. application, and the service life has been greatly improved. At the same time, magnesia carbon bricks do not need to be fired at high temperature, saving energy, and the manufacturing process is simple, so they are quickly popularized and used. A simple tool for storing and transporting molten steel has been transformed into a generating device that can perform vacuum treatment, argon blowing, heating, composition fine-tuning, etc. in the ladle, making...

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Problems solved by technology

[0002] Magnesia-carbon brick is a kind of high-quality refractory material. Because this kind of carbon-containing refractory product has the advantages of high refractoriness, good slag erosion resistance, strong thermal shock resistance and low high temperature creep, it is widely used in electric furnaces, converters and ladles. application, and the service life has been greatly improved. At the same time, magnesia carbon bricks do not need to be fired at high temperature, saving energy, and the manufacturing process is simple, so they are quickly popularized and used. A simple tool for storing and transporting molten steel has been transformed into a generating device that can perform vacuum treatment, argon blowing, heating, composition fine-tuning, etc. in the ladle, making the use of the ladle extremely harsh, especially in the slag line of the ladle, making the slag line Bricks with slag lines frequently appear steamed bun-shaped, that is, the edge erodes faster than the middle of the brick, which seriously affects the later batching of ladles, resulting in frequent off-line ladles during use, which not only affects the production rhythm, but also buryes hidden dangers for safety. It has become a restrictive link in the development of variety steel

[0003] After research, it was found that the main factors affecting the appearance of steamed buns in ladle slag line bricks: 1) The expansion coefficients of the magnesia aggregate and the matrix are inconsistent, and the relative expansion coefficient of the aggregate is greater than that of the matrix, resulting in irreversible expansion after heating; 2) due to the Introduce a large amount of flake graphite, and the graphite will have the phenomenon of "heating stretching and hardening" after heating; 3) After heating, the magnesia carbon brick will not expand freely due to the limitation of the steel shell, but excessive expansion will lead to excessive thermal stress , resulting in reduced thermal shock resistance, and the corners may be crushed

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