Abstract: Method for purifying molten metal having a specific density and including one or more foreign elements to be removed, by (a) cooling the molten metal to a eutectic temperature to simultaneously form purified metal crystals and crystals including at least one foreign element, and (b) separating at least some of the purified metal crystals from the crystals including at least one foreign element by adjusting the molten metal specific density within a range delimited by a lower value being specific density of the purified metal crystals and an upper limit being specific density of the crystals including the at least one foreign element. The molten metal specific density is adjusted to this range by addition of a metal to alter the molten metal specific density and maintained within this range during separation. The method is advantageously applicable for purification of aluminium melts from recycle aluminium and aluminium scraps.
Abstract: A method and device for the purification and separation of purified metal from a metal mother liquid having a specific density and comprising one or more foreign element(s). The method includes: providing in a column device a starting material including metal crystals and a metal mother liquid including at least one foreign element; applying a temperature difference between a relatively hot zone at the upper end of the column and a relatively cool zone at the lower end of the column; a separation step wherein at least a part of the metal crystals is separated from the metal mother liquid by rising of the metal crystals to the upper surface of the metal mother liquid; and a further separation step wherein purified metal floating on the upper surface of the metal mother liquid is discharged from the column device.
Inventors:
Huibrecht Adriaan Wouters, Andreas Ten Cate, Elisabeth Maria Beunder, Willem Boender, Marcellus Albertus Hogenboom, Rene' Kieft, Joost Christiaan Storm