Preparation process for refractory brick on ladle slag line

Abstract

The invention discloses a preparation process for a refractory brick on a ladle slag line. The preparation process comprises the following steps of (1) placing waste magnesia bricks, fused magnesia, silicon carbide, zirconia, fused millite and magnesite powder into a mixer to be mixed for about 45-60 minutes; (2) adding graphite powder, asbestos fibers, Suzhou bentonite, zirconium boride, boron nitride and cerium oxide, and mixing for about 120-135 minutes; (3) adding asphalt powder, phenol formaldehyde resin, sodium hexametaphosphate and water, and further mixing for about 150-180 minutes; (4) molding by using a press machine, and drying a green brick at the temperature of 200 DEG C for 24 hours; and (5) calcining at the temperature of about 1800-1840 DEG C, and preserving the heat for about 16-18 hours. The refractory brick prepared by using the preparation method has the following excellent performances: molten steel is recarburized by at most 2.3ppm, the volume density is 3.05-3.15g / cm<3>, the apparent porosity is 1.5-2.5%, the normal-temperature compressive strength is larger than or equal to 45MPa, the 1400-DEG C high-temperature bending strength of buried carbon is larger than or equal to 33Mpa, and the 1400-DEG C linear expansion coefficient is 1.35-1.45%. Through measuring the thermal shock resistance of the refractory brick prepared by using the preparation process disclosed by the invention by using an air quenching method comprising the step of carrying out air cooling once at the temperature 1100 DEG C, the residual strength retention rate is measured to be 74-76%.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a preparation process of a ladle slag line refractory brick. Background technique [0002] At present, the total carbon content of ordinary magnesia-carbon bricks for ladle slag line is generally 10-18wt%, and one of the main reasons for the damage of magnesia-carbon bricks is due to the oxidation of carbon in the bricks, so that steel slag is easy to penetrate, which makes the erosion intensified, but it has been The research carried out on low-carbon magnesia-carbon bricks mainly focuses on the research of binders and carbon raw materials, such as: "Magnesia-carbon bricks containing antioxidant C-TiN composite powder and its production method" disclosed in the Chinese patent application number 200610046434.0 "C-TiN composite powder is used as antioxidant and graphite, fused magnesia, and binder respectively after mixing, molding, and heat treatment to improve ...

AI Technical Summary

Problems solved by technology

[0002] At present, the total carbon content of ordinary magnesia-carbon bricks for ladle slag line is generally 10-18wt%, and one of the main reasons for the damage of magnesia-carbon bricks is due to the oxidation of carbon in the bricks, so that steel slag is easy to penetrate, which makes the erosion intensified, but it has been The research carried out on low-carbon magnesia-carbon bricks mainly focuses on the research of binders and carbon raw materials, such as: "Magnesia-carbon bricks containing antioxidant C-TiN composite powder and its production method" disclosed in the Chinese patent application number 200610046434.0 "C-TiN composite powder is used as antioxidant and graphite, fused magnesia, and binder respectively after mixing, molding, and heat treatment to improve the slag resistance and prolong the service life. However, due to the high cost of titanium raw materials High, it is difficult to popularize and use, and the carbon content of the magnesia-carbon brick is high, it will add carbon to the molten steel; the application number is 200710019767.9 Chinese patent "a non-oxide composite low-carbon magnesia-carbon brick" introduces the magnesia-carbon Introducing non-oxides (nitrides or borides) into the bricks to prepare low-carbon magnesia-carbon bricks with a carbon content of less than 6%, which maintains the performance of high-carbon magnesia-carbon bricks, because it adds pre-synthesized non-oxidized The cost is high, and the hydration reaction may occur, and the performance improvement is not obvious; the application number is 99107800.4 Chinese patent "antioxidant for carbon-containing refractory materials" introduces an antioxidant, which consists of 0.15 to 10% (weight) Zinc powder or zinc powder and at least one of aluminum, magnesium, silicon, silicon calcium powder, silicon carbide, boron carbide, magnesium aluminum alloy powder, silicon nitride powder, wherein the zinc powder is ≥0.15%, and the particle size is less than 0.5mm , the addition of metal powder is only used to prevent the oxidation of carbon in carbon-containing refractory materials, and has no effect on the high-temperature mechanical properties of refractory materials