Carbon-free high-purity aluminum magnesium machine pressing brick for refining steel ladles as well as preparation method thereof

Abstract

The invention discloses a carbon-free high-purity aluminum magnesium machine pressing brick for refining steel ladles as well as a preparation method thereof. The carbon-free high-purity aluminum magnesium machine pressing brick comprises the following raw materials in parts by weight: 50 to 75 parts of corundum particles, 15 to 35 parts of a corundum fine powder, 1 to 5 parts of an activated aluminum oxide powder, 1 to 55 parts of a calcined aluminum oxide powder, 3 to 7 parts of a metal powder additive, 4 to 10 parts of a magnesium aluminum ultrafine powder binding agent and 1.5 to 4 parts of water. The carbon-free high-purity aluminum magnesium machine pressing brick prepared by the method has the characteristics of compact structure, high normal-temperature, medium-temperature and high-temperature strength, high thermal shock stability, slag erosion resistance, excellent permeability and the like, and can greatly prolong the service life when serving as a steel ladle work lining resistant material.

Description

Technical field [0001] The invention belongs to the technical field of refractory materials for steelmaking, and mainly relates to a carbon-free high-purity aluminum-magnesium press brick for refining ladle and a preparation method thereof. Background technique [0002] The ladle is an important thermal equipment in the metallurgical industry, and its most primitive and basic function is to hold, transfer and pour molten steel. With the rapid development and technological progress of the metallurgical industry, various industries and fields have higher and higher requirements for the quality and performance of steel. The molten steel is generally subjected to secondary refining outside the furnace before pouring, which mainly includes desulfurization, degassing, and removal. Inclusions, adjustment of the composition and temperature of molten steel, etc., the main steelmaking processes involved are LF, RH, RH+OB, VD, VOD, LATS, etc. The above refining process is basically complet...

AI Technical Summary

Problems solved by technology

At present, the working lining of refining ladles at home and abroad is mostly cement or gel-bonded aluminum-magnesium or corundum spinel prefabricated blocks or castables. The main disadvantages in the production and use process are as follows: 1) Carbon-free Prefabricated blocks are labor-intensive in the production process, with low production efficiency, high noise, and a large amount of molds, which brings great inconvenience to the production management process; 2) For castables, there are high requirements for on-site construction operations and environmental The influence of factors fluctuates greatly, the early baking period is long, and the problem of bursting is prone to occur. Under abnormal conditions, it will cause problems such as unfavorable ladle turnover; 3) Both prefabricated blocks and castables have high apparent porosity and relatively low volume density. Molten steel and molten slag are prone to permeation process at high temperature during use, resulting in the problem of structural spalling at the hot end in the middle and late stages of use

The inorganic binder can make carbon-free machine pressed bricks obtain better strength at room temperature, and the inorganic binder decomposes at medium and high temperatures, making the strength of the material lower

At the same time, the above-mentioned inorganic binders will bring in corrosive or toxic volatile components (such as Cl, P and other elements), and will also introduce K into the material. 2 O, N 2 O, CaO, SiO 2 and other impurities, and Al in carbon-free machine pressed bricks 2 o 3 , MgO and other reactions form a low melting phase, thereby reducing the high temperature performance of the material and the corrosion resistance of molten steel and slag

On the other hand, traditional carbon-free machine-pressed bricks generally introduce magnesia particles or fine powder to improve slag erosion resistance and permeability. 2 micronized powder for mitigation, SiO 2 The introduction will form Al in the material 2 o 3 -MgO-SiO 2 and other low melting point phases, which also reduces the high temperature performance of the material and the corrosion resistance of molten steel and slag

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