As a material of traditional industries, refractory materials play an irreplaceable role in the development of the entire high-temperature industry and are one of the basic materials of the metallurgical industry. As a high-temperature container for steelmaking, the primary function of refractory materials is to withstand high temperatures. For the temperature changes and slag erosion in steelmaking, it is required to have the function of smelting molten steel safely and stably. Refractory materials are important basic and auxiliary materials for high-temperature technology. Although there are more or less problems, they have been continuously improved and optimized. As a ceramic material, the raw materials of refractory materials have undergone a series of improvements, and the formulas and finished products have become more diverse to meet various service conditions. The conditions of refractory materials in the production process have been improved, and the process is more in line with the actual environment, ensuring the high quality of refractory products; according to different high-temperature use conditions, the internal microstructure of refractory materials is improved to obtain the expected performance, mainly including the mechanical parameters, thermal shock stability and slag erosion resistance of refractory materials, so as to make its service effect more ideal.
With the birth of high-temperature industry, the refractory industry has emerged and is closely related to the high-temperature industry. Especially in the metallurgical industry, the refractory materials used and consumed each year account for more than half of the total refractory production. Therefore, the development of metallurgical technology can also drive the progress of refractory production technology. The relationship between refractory materials and the steel industry can be described as "prosperity and loss together"; however, with the development of metallurgical technology and changes in social needs, the types of steel products have become more and more abundant, and there are strict control standards for the quality of steel products. In order to meet the needs of high-temperature service conditions, refractory materials are generally mixed and sintered by multiple materials at high temperatures. Therefore, under high-temperature conditions, due to changes in their own physical properties, inclusions will be generated, thereby causing certain pollution to molten steel. In recent years, the problem of steel quality being polluted by refractory materials has attracted the attention of researchers. A lot of research has been carried out on the interaction between refractory materials and molten steel, aiming to analyze the degree and mechanism of the influence of refractory materials on steel quality, as well as how to develop new functional refractory materials that are friendly to molten steel and can even promote the removal of inclusions in molten steel, thereby improving steel quality.
Corresponding refractory materials are used in thermal equipment used in high-temperature sectors of many industries. There are many internal and external factors that affect the service life of refractory materials, but in general, they can be divided into the following two points:
(1) The thermodynamic stability of refractory materials is determined by the composition properties of the materials themselves, which affects the interaction between refractory materials and molten steel, including physical reactions and chemical reactions;
(2) The apparent porosity of refractory materials affects the interaction between refractory materials and molten steel. From a dynamic point of view, the larger the apparent porosity of refractory materials, the faster the interaction rate between refractory materials and molten steel.
Therefore, under the reference of the above conditions, we usually use refractory materials with lower porosity or dense protective layer in structural composition and more stable chemical composition to meet the harsh conditions in the actual steelmaking process. Although refractory materials can meet their stability from the perspective of dynamics and thermodynamics, when using refractory materials with dense structures, the temperature of refractory materials changes during operation due to the actual environment, and the temperature difference is large and the time is short. In addition, refractory materials are affected by the penetration of high-temperature gas, dust and molten steel, which will cause damage to the internal structure of refractory materials.
The development of refractory materials aims to research refractory materials that meet the needs of actual high-temperature environments. By changing the composition, the contact between refractory materials and high-temperature molten steel or slag is prevented, and the erosion of refractory materials is reduced, thereby reducing the damage of refractory materials in thermodynamics. From a kinetic point of view, the main factor of refractory damage is the melting loss of the material. Therefore, what needs to be considered is the structural composition of the material itself, reducing the contact area between the refractory material and the molten steel, and the rate at which the refractory material dissolves and diffuses into the molten steel after contact, thereby reducing the damage rate of the refractory material; for the use of refractory materials, first of all, it is necessary to meet the high-temperature harsh conditions and temperature differences of the refractory materials during service. Secondly, in the refractory materials that meet the above conditions, the structural composition of the refractory materials is improved, the porosity and the contact area between the refractory materials and the high-temperature solution are reduced, and the content of the components involved in the reaction is reduced, so as to research refractory materials that are more in line with social needs.
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