As a special material that can maintain physical and chemical stability at high temperatures, refractories play a vital role in many industrial fields. Its wide application not only ensures the smooth progress of industrial production process, but also has significant significance in improving production efficiency, reducing costs and ensuring product quality.
1. Applications in the steel industry
In the process of steel production, refractory materials are indispensable. From blast furnace ironmaking to steelmaking to ingot casting, refractory materials are needed to withstand high temperatures, chemical erosion and mechanical wear.
1.1. Blast furnace
Blast furnace lining is mainly composed of refractory bricks, such as carbon bricks, high aluminum bricks, etc. Carbon brick has good thermal conductivity and corrosion resistance, and can withstand the high temperature and high pressure in the blast furnace and the wash of hot metal and slag. The high aluminum brick has high refractoriness and mechanical strength, and can keep the structure stable at high temperature to ensure the long-term stable operation of the blast furnace.
1.2. Steel furnace
Refractories are also used extensively in the linings of converter and electric furnaces. Magnesia carbon brick is widely used in the lining of converter because of its good thermal shock resistance and corrosion resistance. The top of the electric furnace is usually made of high aluminum or silicon refractory materials to adapt to the characteristics of high temperature and intermittent operation of the electric furnace.
1.3. Continuous casting
In the continuous casting process, refractory materials are used to make crystallizers, water ports and other parts. For example, the immersion nozzle uses aluminum-carbon materials, which can withstand the erosion and erosion of high-temperature molten steel, while ensuring the smooth outflow of molten steel, providing key technical support for continuous casting steel.
2. The application of nonferrous metal smelting
In the process of non-ferrous metal smelting, due to the high melting point and smelting temperature of the metal, and various corrosive substances may be produced in the smelting process, the requirements for refractories are also very strict.
2.1. Aluminum smelting
In aluminum electrolytic cells, refractory materials such as silicon carbide bricks and alumina bricks are usually used on the side and bottom. Silicon carbide brick has good corrosion resistance and thermal conductivity, and can adapt to the strong corrosive electrolyte environment in aluminum electrolytic cell. Alumina bricks have high refractoriness and chemical stability to ensure the structural integrity of the electrolytic cell.
2.2. Copper smelting
The furnace lining of copper smelting equipment such as flash furnace and reflex furnace often uses magnesia chrome brick, magnesia brick and other refractory materials. These materials can withstand the high temperature and complex chemical reactions in the copper smelting process, effectively resist the erosion of slag, and improve the service life of smelting equipment.
3. Application in cement industry
In the cement production process, the rotary kiln is the core equipment, and its operating temperature is above 1000 ° C, so high-quality refractory materials are needed to ensure the continuity and stability of production.
3.1. Rotary kiln lining
The cylinder of rotary kiln is generally constructed with refractory brick, commonly used are high aluminum brick, magnesia-aluminum spinel brick, etc. These refractory bricks have good high temperature resistance and mechanical strength, and can withstand the wear of materials in the rotary kiln and the erosion of high temperature air flow. At the same time, in order to improve the heat insulation effect, a heat insulation layer will be set on the outer layer of the refractory brick to reduce heat loss.
3.2. Preheater and calciner
The temperature inside the preheater and calciner is also higher and is usually insulated and lined with materials such as ceramic fibers and lightweight firebricks. Ceramic fiber has excellent thermal insulation performance and flexibility, which can effectively reduce the temperature of the equipment housing and reduce heat loss. On the premise of ensuring a certain degree of refractoriness, the light firebrick reduces the weight of the equipment and reduces the construction cost.
4.Applications in the glass industry
In the process of glass production, the furnace is the key equipment, and the quality of refractory materials directly affects the output and quality of glass.
4.1. Glass furnace
Refractory materials are required for the pool wall, bottom and top of the furnace of the glass furnace. The wall of the pool is generally fused zirconium corundum brick or zirconium containing refractory materials, which have good resistance to glass corrosion and high temperature strength, and can withstand chemical erosion and high temperature erosion of glass liquid. Dense chrome or magnesium bricks are often used for the bottom of the pool to ensure the structural stability of the furnace bottom. The furnace top is usually made of silicon brick or high aluminum brick, which is adapted to the high temperature environment at the top of the furnace.
4.2. Glass molding equipment
Refractories are also used in key parts of equipment such as wire drawing machines and bottle making machines during the glass forming process. For example, the molybdenum electrode of the wire drawing machine will be protected by zirconia refractory materials to prevent the electrode from being oxidized and eroded by glass liquid to ensure the smooth production of glass fiber.
5.Application in the power industry
In the power industry, the boilers and other equipment of thermal power stations need to use refractory materials to withstand high temperatures and corrosion.
5.1. Boiler lining
The furnace, flue and other parts of the boiler are usually lined with refractory castable, refractory brick, etc. Refractory castable has the advantages of convenient construction and good integrity, and can adapt to the complex shape and thermal stress changes in the boiler. Refractory bricks are used in some high temperature and serious wear parts, such as near the burner, to improve the wear resistance and refractoriness of the lining.
5.2. Circulating fluidized bed boiler
The wear problem of circulating fluidized bed boilers is more prominent, so special wear-resistant refractory materials, such as silicon carbide wear-resistant bricks and wear-resistant castables, will be used in its furnace, separator and other parts. These materials can effectively resist the erosion and wear of the material and extend the service life of the boiler.
Refractory materials are widely used in many industrial fields such as steel, non-ferrous metals, cement, glass, and electric power. With the continuous development and progress of industrial technology, higher requirements have been put forward for the performance and quality of refractory materials. In the future, the refractory industry will continue to innovate and develop more high-performance, multi-functional refractory materials to meet the growing needs of different industrial fields, and provide a solid guarantee for the efficient, stable and sustainable development of industrial production. At the same time, reasonable selection and use of refractory materials, strengthening the maintenance and management of refractory materials, is also an important measure to improve industrial production efficiency and reduce costs.
