Continuous elimination of Al2O3 particles in molten aluminium using electromagnetic force

Abstract

A new method for continuous elimination of inclusions by using electromagnetic force was designed in this study. The principle is that as the electromagnetic force induced in metal scarcely acts on inclusions owing to their low electric conductivity; they are moved in the direction opposite electromagnetic force and can be separated from the melt. To do this, numerical analysis was conducted by employing the principle of electromagnetic braking. Numerical results agreed well with the experimental ones. Using the continuous electromagnetic separation system designed in this study, it was determined that Al2O3 particles whose size was larger than ~ 14 μm immersed in flowing aluminium melt could be removed under the electromagnetic conditions (electric current density 7.96 × 105 A m-2, magnetic flux density 0.35 T) when the flow velocity was ~ 150 mm s-1.