High-calcium homogenized magnesia carbon brick and preparation method thereof

Abstract

The invention discloses a high-calcium homogenized magnesia carbon brick and a preparation method thereof. The method is used for preparing a high-calcium fused magnesite brick. The high-calcium homogenized magnesia carbon brick is prepared from the following components in parts by mass: 800 to 900 parts of high-calcium fused magnesia, 10 to 80 parts of crystalline flake graphite, 30 to 40 parts of phenolic resin, 5 to 30 parts of antioxidant and 30 to 80 parts of an additive, wherein the additive is a mixture of calcium aluminate with a chemical formula of CaO.Al2O3 and calcium dialuminate with a chemical formula of CaO.2Al2O3, and the particle size of the mixture is 0.5 to 0.045 mm. According to a technical scheme in the invention, the preparation method comprises the following steps: crushing the fused magnesite, feeding the crushed fused magnesite into a closed material box, spraying water for wetting, conducting standing for 24 hours, performing drying, and conducting screening to obtain crushed fused magnesite with three granularities for later use; premixing the additive and the antioxidant for later use; mixing the sieved granular materials, the phenolic resin, the crystalline flake graphite and the premix; performing compression molding to obtain a green brick; and conducting drying. The problems that a low-carbon brick is low in thermal shock resistance and easy to peel off at high temperature and a magnesium-calcium-carbon brick is easy to hydrate are solved in the invention.

Description

technical field [0001] The invention relates to the technical field of refractory materials for iron and steel enterprises, in particular to a calcium-magnesia-carbon brick and a preparation method thereof. Background technique [0002] The traditional production of low-carbon steel, stainless steel and other ladle refractories mainly use MgO-C bricks, that is, magnesia-carbon bricks. With the rapid development of clean steel and ultra-low carbon steel smelting technology, low-carbon magnesia-carbon bricks have begun to be used by reducing the Graphite content to reduce carbon addition to molten steel. Low-carbon magnesia-carbon bricks generally reduce the graphite content on the basis of ordinary magnesia-carbon bricks, and control the carbon content between 4-8. However, after the graphite content is reduced, the thermal shock resistance of magnesia-carbon bricks will inevitably lead to poor thermal shock resistance. It is easy to peel off, resulting in a reduction in the...

AI Technical Summary

Problems solved by technology

[0004] However, due to the existence of free CaO, the raw materials used in the preparation process of MgO-CaO-C bricks are very easy to absorb moisture and hydrate in the atmosphere to form hydroxides, resulting in reduced product strength and even collapse.

It is difficult to avoid the hydration of calcium in the process of production, storage and transportation, which leads to problems such as low yield, short storage time or unusable products

In order to avoid the hydration of magnesia-calcium-carbon bricks, measures such as wax dipping or vacuum packaging of magnesia-calcium-carbon bricks are required, resulting in high production costs, and the hydration problem cannot be completely solved in the whole process of production, sales, storage and transportation.

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