METHOD OF REFINING ALUMINUM MELTS TO REMOVE MAGNESIUM Russian patent published in 1998 - IPC

FIELD: aluminum production. SUBSTANCE: aluminum refining includes removal of magnesium, hydrogen, and nonmetal inclusions from secondary aluminum melts and consists in treating the latter with metal chloride melts followed by separating metal and reaction products. As metal chloride, cuprous chloride fusion cake with sylvinite at ratio 1:(2.5-3) is used and added to aluminum melt at temperature constituting 1.07-1.15 melting temperature of cuprous chloride fusion cake and with intake ensuring 0.35-0.4 stoichiometric quantity of cuprous chloride. Invention eliminates transfer of iron impurity into melt and, when primary and secondary copper-containing alloys are refined, transfer of copper metal into melt is economically favorable factor. Required degree of magnesium removal without iron pollution of melt is twice as low as in prototype method, metallurgical yield is increased more than by 10%, and degree of removal of hydrogen and nonmetal inclusions is not below than in prototype method. EFFECT: reduced operational expenses. 1 tbl