Abstract
The previous work on the ladle refining of MG-Si has first been reviewed. Because of the nature of ladle refining process, i.e. the highly dispersed, strongly stirred liquid at high temperatures, the system is closed to the equilibrium. The local equilibrium assumption can be applied to simulate the ladle refining of MG-Si process. The chemical kinetic analysis has shown that the diffusivity of ionic Al in the slag phase and transportation of impurities (Al and Ca) from bulk melt to the gas/metal/slag interface are probably the main rate steps in the process. A thermodynamic analysis provides the following two main contributions: - Equilibrium distributions of SiO and SiO2 as function of temperature and initial gas compositions; - Equilibrium partition coefficients of Al and Ca between metal and slag phases.The thermophysical properties for modelling of the process, e.g. density, viscosity, thermal conductivity and surface tension of gas mixture, liquid metal and molten slag, have finally been evaluated and mathematical expressed in the present report.
