Study On Wettability And Corrosion Of Coal Ash On The Surface Of Different Refractories

Coal is essential fuel to high temperature applications including blast furnace, boiler and gasifler. Refractory lining material in high temperature applications could not avoid corrosion and damage of coal ash during the process of sintering. The corrosion and damage not only affect the service life of refractory material, but also influence the safe operation of the high temperature applications. According to the problems mentioned above, the thesis analyzes the wettability and corrosion of molten slag on refractory material so as to provide theoretical basis for choosing refractory lining material.Shen Mu and Sheng Li, two varieties of coal ash, are chosen to analyze the wettability and corrosion on five different refractory materials. In the test of wettability of molten slag on refractory materials, coal ash is made into coal ash cylinder first, and then contact angle changes and moiphological changes of coal ash cylinder are observed as the surface temperature of refractory materials increase. That aims to judge and compare the wettability of two coal ash on the surface of different refractory materials. In the test of corrosion of molten slag on refractory materials, erosion morphology features of different refractory materials made by coal ash at various temperatures are observed and SEM and EDS are adopted to observe and test permeation and corrosion of coal ash on refractory materials. Further more, scanned image and element curve of morphology of ash and cross section of refractory materials are analyzed and studied. In addition, Al2O3and CaO are added to change components of coal ash in order to analyze the corrosion of coal ash on refractory materials.The results of experiments show that:temperature, coal ash type and refractory materials varieties are important factors which influence the wettability and corrosion of coal ash on refractory materials. In fact, the corrosion of coal ash on refractory materials is the result of corrosion and permeation between coal ash and mineral elements of refractory materials. During the process of corrosion, chemical reaction inhibits or promotes the corrosion. The corrosion and wettability of molten slag on refractory materials are basically consistent.