Magnesium chrome three-layer composite brick and preparation method thereof

Abstract

The invention provides a magnesium chrome three-layer composite brick with good abrasive resistance, high degree of fire resistance, high structural strength and good heat-preservation and heat-insulation performance, and a preparation method of the magnesium chrome three-layer composite brick. With the adoption of the magnesium chrome three-layer composite brick and the preparation method, the integrated function of fire resistance and heat insulation of the composite brick is realized, and the energy-saving effect of a rotary kiln is improved. The magnesium chrome three-layer composite brick comprises a heavy work layer prepared by taking a magnesium zirconium material as a raw material, a soft heat-insulation layer prepared by taking an electric melting hollow ball as a raw material and a transition layer between the heavy work layer and the soft heat-insulation layer. The transition layer is prepared by taking spinel, or magnesium aluminum chromium, or magnesium aluminum titanium, or magnesium spinel zirconium as a raw material. According to the magnesium chrome three-layer composite brick, the transition layer is introduced, the heavy work layer and the soft heat-insulation layer can be avoided to be reacted, a product can have good fire-resistance and heat-insulation performances without reducing the service life of the material, and therefore, the roles of saving energy consumption, reducing material consumption and reducing dosage of a fire resistance material of the rotary kiln are played, 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-chrome 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 ma...

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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