Corrosion Mechanism and Wear Prediction of the Sole of an Electric Arc Furnace

摘要

There are many alternatives for the refractory lining in the sole of an electric arc furnace that produces refined ferromanganese, Fe-Mn (80% with low carbon content, %C<1.5). Empiric approaches have usually been used for the design. Even though they allowed increasing the number of tapping, they are not base in a quantitative prediction of the wearing from the knowledge of a corrosion mechanism. This paper presents a quantitative prediction for the corrosion processes in two basic soles using the mathematical formulation of the Nodal Wear Model (NWM). In both cases, the equations that describe the corrosion are established and applied, according to the control mechanism of the corrosion, in each node of a Finite Element Model (FEM) grid of the refractory lining is in contact interface with the liquid ferroalloy. When the sole formed by a magnesite castable refractory (with a minimum content of 95% periclase), the penetration of the molten phase through the open porosity of the refractory controls the corrosion. In the case of a dolomitic sole (75% MgO, 20% CaO, 0.60% SiO_2, 3.80% Fe_2O_3, Al_2O_3=0.30%), the corrosion rate is controlled by the diffusion of silicon, one of the active components of the refractory matrix, from each interfacial node in the sole to the molten phase.