The electric furnace cover lining is the weak link of the whole furnace body. Due to the influence of operating factors and structural factors, it puts forward harsh requirements on the resistant material. Factors affecting the life of the furnace cover are mainly: 1, thermal shock. Arc heating, temperature changes caused by the discharge of steel and cover movement; 2, chemical erosion. Slag steel splash to the surface, causing chemical erosion, as well as the furnace CO, CO2, SiO2, etc.; 3, arc radiation. Arc heating heat radiation caused by the melt loss; 4, high-speed dust extraction in the furnace to form a high-speed airflow wear; Therefore, the refractory materials used in the furnace cover requires good thermal shock, the slag high-temperature splashing resistance to erosion, as well as the integrity of a good, solid structure does not crack and so on.

According to the requirements, our company utilizes the modern material science and technology, according to the principle of compound phase modification, scientific configuration and elaborate production, and successfully developed a long-life type castable prefabricated block, which contains two series: one is Aluminum - Chromium system. It can be used in all kinds of high-power or ultra-high-power electric furnaces. 　　The other series is aluminum-spinel system, which is especially useful for the triangle area at the top of the furnace. 　　This kind of castable material is cited to the intermediate package flow stabilizer, impact brick and slag wall has achieved good results.