Elimination of tramp elements in molten metal using electromagnetic force

J. P. Park - Y. Tanaka - K. Sassa - S. Asai

Department of Materials Processing Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-01, Japan

Abstract
Two new electromagnetic methods for eliminating tramp elements are proposed. The first one makes use of the electromagnetic force induced by imposing a direct electric current and a steady magnetic field, and the second makes use of the force induced by a travelling magnetic field. The key point of the methods is the adoption of a bundle of thin pipes or a filter brick so as to suppress the electromagnetically driven fluid motion which makes the electromagnetic separation meaningless. It was confirmed by visualizing the movement of polystyrene particles dispersed in a transparent aqueous solution that the fluid motion in a thin pipe was substantially constrained. The usefulness of the methods were also demonstrated in the experimental works using molten aluminum alloys including iron as a tramp element and a molten tin including an intermetallic compound. The elimination of the iron molten in aluminum will be an indispensable technology for recycling aluminum scraps. Figs 12, refs 5.