Abstract: A filter system for removing solid impurities from molten metal is described comprising a housing containing vertically disposed rigid coarse filter facing the incoming flow of molten metal and capable of removing solids having a particle size of at least 10 microns and a rigid fine filter mounted vertically behind the coarse filter and capable of removing solids having a particle size as small as 1 micron. The apparatus further includes a heater for maintaining the temperature of the molten metal and a sparger mounted adjacent the front face of one filter to provide an intermittent gas flow over the face of the filter to dislodge solids on the filter as filter cake. In a preferred embodiment, the rigid filters are nested cylinders, and the molten metal is directed to the center of the smaller coarse filter cylinder from which it then flows through the coarse filter outward to and through the fine filter cylinder and then from the fine filter out of the filter housing.

Abstract: An apparatus for improving the surface characteristics of a continuously cast metal ingot comprises: a skim dam having outer lateral edges which diverge downwardly into an upper molten surface of the ingot during casting in a mold; and means for suspending the skim dam in the upper molten surface. Preferably, the outer lateral edges intersect the upper molten surface at an angle between about 105.degree. and 150.degree., and more preferably at about a 120.degree. angle. The outer lateral edges maintain an acutely angled meniscus inwardly of the meniscus between the upper molten surface and the side surfaces of the ingot. A method for inhibiting the formation of vertical folds and oxide releases on a metal ingot continuously cast in an electromagnetic mold comprises suspending a skim dam in an upper molten surface of the ingot during casting, said skim dam having outer lateral edges which are not wetted by the upper molten surface and diverge downwardly into same.