Effect of Temperature on Dephosphorization of Ferrosilicon using Electromagnetic Levitation Technology under Vacuum

Abstract

Electromagnetic levitation (EML) is a novel contact-less process which avoids the contaminant from the crucible at high temperature. EML is also praised for providing great kinetics condition. The technology plays a very good role in the dephosphorization of ferrosilicon for the photovoltaic industry. In this research, the influence of the magnetic field on the temperature field under levitated conditions is studied. Building the coupling model of magnetic field and temperature field. The research uncovered that the magnetic field where the specimens are changed corresponding to the shape of specimens. The range of the temperature of the temperature field where the specimens does not vary a lot. It’s due to the Joule heat generated by electromagnetic stirring inside the sample, which makes the temperature uniform. Based on this, the effect of temperature on dephosphorization is researched. The experimental researches have shown that when the levitated ferrosilicon alloy (24% Fe-76% Si) is placed in the flow of argon-hydrogen gas, the phosphorus removal increases with both time and temperature. Upon approaching the equilibrium time point, the reaction becomes mass transfer limited in the liquid phase. It’s observed that an equilibrium time point exists at approximately 45 minutes, for which the concentration of phosphorus remains constant, independent of increasing refining time. Higher processing temperature results in lower final [P] content, with a 72% rate of removal achieved after 40 minutes of levitation at 1720°C.