Describe the application fields and basic requirements of refractory materials

1. Main fields of application of refractory

     Materials among them, the most common application is as a structural material and lining to resist high temperature in various thermal equipment and high temperature containers.

     In the iron&steel metallurgical industry, coke ovens are mainly composed of refractory materials. Iron-making blast furnaces and hot blast furnaces, various steel-making furnaces, soaking furnaces, heating furnaces, etc. are absolutely indispensable for all kinds of refractory materials that meet the requirements. Not only does the die casting of molten steel consume a lot of refractory materials, but continuous casting also requires some high-quality refractory materials.
Out-of-furnace refining cannot be achieved without high-quality refractory materials. Statistics show that the iron and steel industry is the sector that needs the most refractory materials, accounting for about 60% of the total output of refractory materials.

     Pyrometallurgy and thermal processing of non-ferrous metals are also inseparable from refractory materials. The building materials industry and other high-temperature operating sectors that produce silicate products, such as the glass industry, the cement industry, and the ceramic industry, all high-temperature furnaces or their linings must be constructed of refractory materials.
Others such as chemical industry, power, machinery manufacturing, etc. all require refractory materials.

     In short, when a certain structure, device, equipment or container is used or operated at a high temperature above about 1000°C, due to physical, chemical, mechanical and other effects, the material may be deformed, softened, melted or eroded, eroded, or The occurrence of cracking damage and other phenomena may not only make the operation unsustainable, interrupt the service period of the material, affect the production, but also pollute the processing object and affect the quality of the product. Therefore, such a refractory material with high temperature resistance must be used. 

2. Basic requirements for refractory materials 

    High temperature operation departments all require refractory materials to have the performance of resisting high temperature heat load. Due to different operation departments, even in different parts of the same kiln, the working conditions are not the same. Therefore, the requirements for refractory materials are also different. Based on the general working conditions of ordinary industrial kilns, the following requirements are generally put forward for the performance of refractory materials: resistance to thermal and high temperature composite action, no softening, no melting, and refractory materials with relatively high refractoriness are required.



     Resistant to high temperature thermal load, no volume shrinkage and only uniform expansion, the material is required to have high volume stability, small residual shrinkage and residual expansion, and no crystal transformation and serious volume effects. Resistant to the combined action of high temperature rapid heat load and heavy load, without loss of strength, creep and collapse, the material is required to have relatively high normal temperature strength and high temperature thermal strength, high load softening temperature, high creep resistance . Resistant to rapid changes in temperature or uneven heating, no cracking, no peeling, and requires materials to have good thermal shock resistance. Resistant to chemical attack by molten liquid, dust and gas, without deterioration and corrosion, the material is required to have good slag resistance. Resist the erosion, impact and wear of flame and charge, Liao Chen, and the surface is not lost, requiring materials with low vapor pressure and high chemical stability. In addition, in order to ensure the overall quality of the structure or lining made of block refractory materials, good slag resistance and air tightness, and easy construction, it is also required that the material has a neat shape, accurate dimensions, and a certain tolerance. existing defects. In order to withstand the impact and possible mechanical vibration and extrusion during handling, the material must have a relatively high normal temperature strength. For some special requirements, sometimes also consider its thermal conductivity and electrical conductivity. It should be noted that although the above points can be used as a basis for evaluating the quality of refractory materials, no single refractory material can fully meet all the above requirements. When selecting or evaluating refractory materials, the outstanding characteristics of the materials must be adapted to the conditions of use and make the best use of them. while taking into account economic accounting