Carbon-free alumina-magnesia unburned brick and preparation method and application thereof

Abstract

The invention relates to a carbon-free alumina-magnesia unburned brick and a preparation method and application thereof. The carbon-free alumina-magnesia unburned brick is characterized by comprising particle size distribution electro-fused white corundum, electro-fused magnesite, magnesia micro powder, alumina ultramicro powder and a small amount of plasticizer and wetting agent. The unburned brick is applied to 300-ton refined steel ladles and has high heat-insulating property, and the service life of the steel ladles exceeds that (90 to 100 furnaces) of the conventional alumina-magnesia brick greatly.

Description

technical field [0001] The present invention relates to a carbon-free aluminum-magnesium unburned brick, its preparation method and its application. More precisely, the invention relates to a high-quality variety of clean steel smelting ladle lining working layer molten iron zone refractory aluminum-magnesium unburned brick, Preparation method and application, especially related to a kind of carbon-free magnesia unfired brick, which is prepared by gradation and preparation of superfine powder particles such as fused corundum sand, fused magnesia, pre-synthesized fused spinel sand, alumina, etc. made. It belongs to the field of refractories for smelting high-quality crystalline steel. Background technique [0002] With the continuous improvement of the market's quality requirements for steel products, the technical level of the modern steel industry must continue to improve. Low-carbon and ultra-low-carbon clean steel has become the focus of development. Among them, the ladl...

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Problems solved by technology

[0003] At present, the refractory materials in the molten iron area of ​​the refining ladle are mainly shaped aluminum-magnesium-carbon bricks and aluminum-magnesium castables. Because the aluminum-magnesia-carbon bricks contain a relatively high content of carbon, it is easy to cause carburization of the molten steel, and the thermal conductivity is high. 10-20W / (m·K), the heat transfer is fast, the heat loss is too large, which affects the normal pouring of molten steel and thus limits its use; aluminum-magnesium castables are prone to occurrence due to high quality control requirements for pouring and baking. Unsafe events such as baking cracks and local abnormal ring damage are not convenient for on-site production management, and SiO in aluminum-magnesium castables 2 The content is usually high, so at high temperature, it is easy to combine with Al 2 o 3 , MgO, CaO and other components form low-melting materials, which is unfavorable to the high-temperature performance of refractory materials. Its high-temperature strength and load softening temperature will decrease, and its corrosion resistance is poor, so it has a certain impact on service life.

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