The slag resistance of zirconium dioxide refractories refers to their ability to resist slag erosion at high temperatures, which is one of the important indicators for evaluating the performance of refractory materials. The following is a detailed analysis of the slag resistance of zirconium dioxide refractories:
I. Overview of slag resistance
Slag resistance is mainly affected by the chemical composition, mineral composition, organizational structure of the refractory itself, and the properties and interaction conditions of the slag (such as temperature, time, flow rate, etc.). The mechanism of slag erosion and destruction of refractory materials is complex, including physical and chemical effects such as penetration, dissolution, and melt scouring.
II. Characteristics of zirconium dioxide refractories
Chemical stability: Zirconium dioxide (ZrO2) has excellent chemical stability, can maintain its structural stability at high temperatures, and is not easy to react chemically with slag.
High melting point: ZrO2 has a high melting point, which allows it to maintain good physical properties under high temperature conditions.
Metal erosion resistance: Zirconium dioxide refractories have good erosion resistance to metals, which makes it have a wide range of application prospects in specific high-temperature metallurgical environments.
3. Slag resistance of zirconium dioxide refractories
Experimental verification: Studies have shown that the cubic phase of ZrO2 in ZrO2-MgO refractory materials made from baddeleyite concentrates does not decompose at high temperatures (1500~1600℃) and in the presence of highly alkaline slag-forming agents. This indicates that the material can resist the erosion of slags of different compositions at high temperatures and has excellent slag resistance.
Application example: Due to the slag resistance of zirconium dioxide refractories, it is widely used to manufacture sizing nozzles for continuous casting machines and embedded layers for sliding nozzle slides for casting special grades of steel. In these applications, the refractory needs to be in contact with the slag at high temperatures for a long time without serious erosion.
4. Factors affecting slag resistance
Chemical composition: When the chemical composition of the refractory is similar to that of the slag, high-temperature melting is likely to occur, thereby accelerating the chemical reaction and erosion process. Therefore, selecting the right refractory to match the specific slag composition is the key to improving slag resistance.
Mineral composition and structure: When there are many high-melting-point crystalline minerals in the refractory, the liquid phase viscosity is large and evenly distributed, its slag resistance is usually good. In addition, reducing the impurity content in the matrix or increasing the direct bonding rate can also improve the slag resistance of the refractory.
Temperature: High temperature will increase the liquid phase volume of the refractory and slag and reduce the liquid phase viscosity, thereby accelerating the reaction rate of chemical corrosion. Therefore, refractory materials used in high temperature environments need to have higher slag resistance.
Zirconia refractory materials have broad application prospects in the field of high-temperature metallurgy due to their excellent chemical stability, high melting point and resistance to metal corrosion. Its slag resistance has been proven to be reliable through experimental verification and practical application. However, in practical applications, it is also necessary to select suitable refractory materials according to the specific slag composition and working environment conditions to improve its slag resistance and service life.
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