Study of electromagnetic separation of nometallic inclusions from aluminum melt

Abstract

Several methods using the concept of electromagnetic separation of nonmetallic inclusions from an aluminum melt were analytically studied and compared in this article. The migration rate of inclusion particles for each method by exerting different types of electromagnetic field, viz. DC electric field with steady magnetic field, AC magnetic field, and AC electric field, was calculated and compared with the gravity settling velocity. Effects of various operating parameters, such as the imposing time of electromagnetic field, the radius of circular pipe, and the magnitude of electromagnetic force, on inclusion removal efficiency were analyzed and illustrated for each case. It was found that the removal efficiency increases with the increase of imposing time and decreases dramatically with the increase of pipe radius, especially for the AC electric field method. As far as the removal of small inclusions is concerned, the AC magnetic field method is the most favorable one because it has the least dependence of removal efficiency upon the particle size. However, high frequency is needed in order to get the optimum results, and the best values of a/␦ are in the range of 2 to 3.

Electromagnetic Separation of Nonmetallic Inclusion from Liquid Metal by Imposition of High Frequency Magnetic Field

“…The methods of the imposition of the electromagnetic force are classified into the following six types: (a) simultaneous imposition of direct current and stationary magnetic field, [1][2][3] (b) imposition of alternating current, 4) (c) imposition of alternating magnetic field, [5][6][7][8] (d) imposition of traveling magnetic field, 9) (e) simultaneous imposition of alternating current and alternating magnetic field, 10,11) (f) imposition of stationary magnetic field. 12) In addition to these studies, Shu et al 13) and Makarov et al 14) recently investigated the availability of the electromagnetic separation theoretically.…”

Effects of Secondary Flow on the Electromagnetic Separation of Inclusions from Aluminum Melt in a Square Channel by a Solenoid.

“…15) Experimental results 11) show that the electromagnetic separation is effective even in the case with strong electromagnetic stirring for this scheme. Although a stationary liquid model and a complete mixing model 9) were presented to calculate the separation efficiency of inclusions, effects of the induced flow on the particle behavior and the overall separation efficiency are yet to be investigated in such separators.…”

Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes

“…[57] Larger particle size, longer treatment time, larger effective magnetic flux density and smaller cross section area of the channel favor the removal of inclusions from the molten silicon.…”