Magnesium three-layer composite brick and preparation method thereof

Abstract

The invention provides a magnesium three-layer composite brick with high wear resistance, fire resistance, structural strength and heat preservation and thermal insulation properties and a preparation method thereof. The fire-resistant and thermal insulation integrated functions of the composite brick are realized, and the energy-saving effect of a rotary kiln is improved. The magnesium three-layer composite brick comprises a heavy working layer prepared from a magnesium material, a light thermal insulation layer prepared from electro-fused hollow spheres, and a transition layer which is positioned between the heavy working layer and the light thermal insulation layer and prepared from spinel or magnesium-aluminum-chromium or magnesium-aluminum-titanium or magnesium-spinel-zirconium. The transition layer is introduced into the magnesium three-layer composite brick, so that the heavy working layer and the light thermal insulation layer can be prevented from reacting, and a product has high fire-resistant and thermal insulation effects under the condition that the service life of a material is not shortened; and therefore, the effect of reducing energy consumption, material consumption and the using amount of a fire-resistant material of the rotary kiln is achieved, and the service life of equipment can be effectively prolonged.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a magnesia three-layer composite brick and a preparation method thereof. Background technique [0002] With the continuous emergence of new technologies for cement production, the main equipment of cement production is developing in the direction of large-scale, increasing production, improving quality, saving energy, reducing consumption, and reducing costs have become the key to increasing efficiency in production management. Most of the existing refractory bricks and heat insulation bricks are made of a single material. When using them, bricks with various properties need to be used together. If they are used on relatively fixed equipment, such as tunnel kilns and downdraft kilns, they can meet the requirements. , but on some relatively moving equipment, such as a rotary kiln, it is difficult to meet the requirements when used together. Some manufactu...

AI Technical Summary

Problems solved by technology

Most of the existing refractory bricks and heat insulation bricks are made of a single material. When using them, bricks with various properties need to be used together. If they are used on relatively fixed equipment, such as tunnel kilns and downdraft kilns, they can meet the requirements. , but on some relatively moving equipment, such as a rotary kiln, it is difficult to meet the requirements when used together

Some manufacturers and research units have conducted research and research on this, and have introduced some composite bricks that combine heavy materials and light materials. However, due to the low structural strength of the light parts, they cannot meet the requirements for use, and the The light part is easy to react due to material problems, which affects product performance and use effect, so it has not been widely promoted, and heavy bricks are still the main ones

[0003] Taking the 10,000t / d rotary kiln of Conch Group as an example, spinel bricks are used in the front transition zone, and magnesia-chrome bricks are used in the firing zone. Due to the large thermal conductivity of spinel bricks in the front transition zone and magnesia-chrome bricks in the firing zone (≥ 2.7W / m·K), so that the temperature of the outer wall of the kiln shell is relatively high (about 380°C, and it can reach 420°C at high temperature), which will increase the heat dissipation of the kiln shell on the one hand, thereby increasing the heat consumption of clinker. It will cause an increase in the unit cost of clinker; on the other hand, it is very easy to cause the cylinder to expand due to heat, resulting in an increase in the temperature of the supporting wheel in the middle of the kiln, especially in the later period of use or in summer, which will bring great hidden dangers to the normal operation of the equipment.

The overheating of the cylinder increases the damage probability of mechanical equipment and accelerates the deformation of the cylinder, and the deformation of the cylinder accelerates the mechanical damage of the inner lining. The result is brick falling and kiln shutdown, which affects the operation rate of the cement rotary kiln

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