Electric furnace integral casting furnace cover and refractory prefabricated technology
At present, basically all the refractory prefabricated blocks have been used in the triangle area of the electric furnace cover in China. The main materials are corundum, chrome corundum, high alumina, and mullite. The refractory prefabricated block has good integrity and erosion resistance, simple and convenient masonry construction and relatively guaranteed construction quality, which greatly improves the overall quality of the electric furnace cover. Corundum (chrome corundum) prefabricated parts are generally used in the triangular area of the ultra-high power furnace cover.
The products we produce mainly use fused white alumina or dense alumina, the critical particle is 5mm, and alumina cement (Al2O3> 80%) is used as the binder. In order to improve the sintering performance of corundum products, a certain amount of ultrafine powder and additives are added. Chrome corundum products are added with some high-quality chromium oxide powder (Cr203> 95%) or chromium corundum powder (Cr2O3 content is about 13%) to increase the viscosity of the slag during high temperature use, reduce the slag penetration layer, and improve the product's resistance. Corrosive. This corundum and chrome corundum prefabricated block is used in the triangle area of the ultra-high power electric furnace cover, and the service life is about 150 furnaces.
The main raw material of corundum castable is corundum (Al203> 98.9%), and fused pure calcium aluminate cement as binder (Al2O3> 80%, Fe2O37%, SiO20.5%). In order to increase the medium temperature strength of the castable and improve its fluidity, a part of -Al2O3, ultra-fine powder (less than 1 micron occupying more than 60%) is added, and its specific surface area is 6.8m2 / g. In order to increase the dispersibility of cement, reduce the amount of water added to the castable, add an organic water reducing agent, and add 5.5% water. The sample calcined at 1500 Celsius for 5h is observed under a microscope. The structure of the product is compact, the particles are uniformly distributed, and the fine particles in the matrix phase are surrounded by fine powder. It has good resistance to alkali steam erosion, spalling resistance and sufficient medium temperature strength. The castable is used in the triangle area of the ultra-high power electric furnace, with a maximum service life of 120 furnaces, a minimum of 90 furnaces, and an average service life of 103 furnaces, which has met the technical requirements of steel plants and replaced imported products.