Patent ID: 7892318
Filing Date: 2011-02-22
Classification: C22B,Y02P

Abstract:
1. Method for the purification of a molten metal, the molten metal having a specific density and comprising one or more foreign elements, the method comprises the steps of: (a) a cooling step wherein the molten metal is cooled to a eutectic temperature to simultaneously form purified metal crystals and crystals comprising at least one foreign element, and (b) a separation step wherein at least some of the purified metal crystals are separated from the crystals comprising the at least one foreign element by adjusting the specific density of the molten metal within a range delimited by a lower value being the specific density of the purified metal crystals and by an upper limit being the specific density of the crystals comprising at least one foreign element, and wherein the specific density of the molten metal is adjusted to this range by the addition of a metal to the molten metal and wherein the specific density of the molten metal is maintained within this range during separation.