Removal of non-metallic inclusions from aluminum by electroslag refining

Abstract

Experiments to remove non-metallic inclusions from aluminum were conducted on a laboratory-scale apparatus by electroslag refining using KCl-NaCl-Na 3AlF 6 flux. It was found that the removal efficiency of electroslag refining for alumina inclusions increases with the decrement of the remelting speed and the removal efficiency can exceed 97% under the remelting speed of 108 g·min -1. The reaction of the molten slag to capture inclusions in the electroslag refining process was the main reason for the removal of inclusions. The Gibbs energy calculation of the inclusion-melt-slag system accounts for the transfer of inclusions from the aluminum melt to the molten slag thermodynamically. © 2011 The Japan Institute of Metals.