Abstract: Molten aluminum or other metals are purified by contacting with a fluorocarbon, such as CCl.sub.2 F.sub.2, in order to decrease the amount of impurity metal elements along with gas and inclusions therein preferably in the presence of an agitator to enhance efficiency. An oxidizer, such as oxygen, is employed to prevent the carbon in the fluorocarbon from forming carbide inclusions. Oxidizing the carbon to carbon monoxide is preferred in treating aluminum since the monoxide effectively removes the carbon from the system without oxidizing aluminum. Preferably, a fluorine acceptor is employed to temporarily combine with the fluorine in the fluorocarbon and prevent it from reacting with carbon such that the fluoride is still available to treat the molten metal. The gases employed to treat the molten metal can be passed over a bed of carbon immediately prior to introduction into the melt.

Abstract: A method of removing skim from molten metal comprises providing a body of molten metal and passing a fluxing gas therethrough to carry skim to the surface of the metal. The skim on the surface is treated to substantially reduce the amount of molten metal contained therein and to provide the skim in a substantially powdery form. A portion of the treated skim in finely divided form is removed to a collector.

Abstract: A method is provided for substantially completely removing volatilizable and combustible impurities from the surface of metallic scrap comprising the steps of continuously depositing surface contaminated scrap onto the surface of a stream of molten metal, directly propelling the floating scrap along the molten surface for a time sufficient for the heat from the molten metal to effectuate substantially complete removal of the contaminants from the scrap and forcibly submerging the remaining decontaminated scrap into the molten metal stream. A system is also provided for removing impurities from the surface of scrap comprising a trough of molten metal, means for moving the molten metal through the trough, means for continuously depositing contaminated scrap onto the molten metal surface, means for propelling the floating scrap through the trough and means for forcibly submerging the remaining floating scrap into the molten metal after the contaminants are substantially completely removed.