Patent ID: 6755889
Filing Date: 2004-06-29
Classification: C22B,F27D

Abstract:
A process for treating molten metal with a particulate treating agent which comprises the steps of:(a) providing a melt of a metal in a treatment vessel, (b) providing a mixing impeller within the treatment vessel beneath the surface of the molten metal, the impeller being selected from the group consisting of a plate with a series of spaced blades extending upwards from a surface of said plate and a flat plate with a series of spaced blades extending downwards from the surface of said flat plate, said impeller being adapted to provide high shear mixing with minimum vortex, and (c) while rotating the impeller on a substantially vertical axis, feeding particulate treating agent together with a small flow of inert gas downwardly through an injection tube below the surface of the molten metal adjacent the upper or lower surface of the impeller in a region between the axis and the periphery of the impeller, whereby the treating agent in the form of molten or partially molten droplets is subjected to a high shearing action causing the treating agent to be quickly formed into finely divided droplets within the molten metal.