A SODIUM-FREE FLUX FOR REMOVING MAGNESIUM IMPURITY FROM MOLTEN ALUMINIUM OR ALUMINIUM ALLOY AND THE REMOVING METHOD OF MAGNESIUM IMPURITY FROM MOLTEN ALUMINIUM OR ALUMINIUM ALLOY USING THE SAME

摘要

PURPOSE: A sodium-free flux for removing magnesium impurity from molten aluminium or aluminium alloy and a method of removing magnesium impurity from molten aluminium or aluminium alloy using the same are provided to control the reaction heat of a flux by using two or more kinds of sodium-free metal fluoride as main components. CONSTITUTION: A sodium-free flux for removing magnesium impurity from molten aluminium or aluminium alloy comprises 60-100 weight% of a eutectic mixture of sodium-free metal fluoride which contains different two kinds of sodium-free metal fluoride. The melting point of the first or/and second sodium-free metal fluoride is 800 C or higher, and the melting point of the eutectic mixture is 700 C or lower. The metal fluoride of the eutectic mixture includes two or more selected from the group consisting of AlF3, KAlF4, K2AlF5, K3AlF6, KF, and K2SiF6.