Investigation of mass transfer processes between metal and slag at film stage of ESR process

Abstract

In this work the results of theoretical and experimental studies the mechanism of refining the metal under ESR are presented, in particular, the role of the different stages of droplet transfer in removing of the harmful impurities and the ways of intensification the most slow phase of the process. The physics and chemical processes of refining are complicated by fluid-flow phenomena, which are connected with capillary formation and gravity waves on the stage of forming the film on butt end of the electrode. This is practically excludes the possibility of the analytical description of hydrodynamics as a single physics and chemical process. By the method of physical modeling, particularities of the mechanism of droplet transfer during ESR are established. Using of the method of integral analogue has allowed obtaining the criteria, which allows to evaluate quantitatively the simulation criterion of the process on physical model. By means of these criterions (Fourier, Fraud, Weber and phase transformation) the physical model is calculated and the scale factors are determined, which are allowed to transfer the results of modeling on real process. It is installed that under melting the consumable electrode yet before the moment of the droplet forming, the break of the film of electrode metal occurs and quick ascent of it‘s part upwards on surface of the electrode that provides intensive liquids mixing in film. It is shown that duration of the metallic film forming on butt end of the steel electrode and direct generations and detachment of droplet consists accordingly 80% and 20% from the time of general cycle of droplet formation. For conditions of ESR by analytical way with use of the Highby diffusion renovation model the equations for determination factors of mass transfer component in system "film of electrode metal-slag" are received, dependence of intensities of mass transfer on velocity of electrode melting is found, part of separate stages in general refining process is determined and the recommendations upon their speedup are given. On the base of the theoretical researches method is designed and equations are received for determination of apparent activation energy of physics and chemical process, which are running in diffusion mode in two-phase system that allows to elaborate the mechanism of passing the refining processes, define the limiting stages and develop scientifically motivated actions upon their speedup