Patent ID: 6602318
Filing Date: 2003-08-05
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 comprising a circular plate with a series of spaced blades extending from a surface of said plate with the blades having a cross-sectional area perpendicular to the movement of the blades such that the ratio of the volume swept by the blades to the area of the impeller plate perpendicular to the axis of rotation is in the range of 0.002 to 0.06 meters, 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 below the surface of the molten metal in a region between the axis and the periphery of the impeller, whereby a high shearing action is created causing the treating agent to be quickly formed into finely divided droplets within the molten metal.