FIELD: nonferrous metallurgy. SUBSTANCE: in a processing method comprising crushing slag, separating it into fractions, water leaching of crushed slag, filtration of solution into salt solution and solid residue, evaporation of salt solution, drying and firing of solid residue, salt solution, prior to be evaporated, is subjected to additional fine filtration and solid residue, prior to be dried and fired, is washed to remove salts, whereas water leaching is performed at water temperature 25-50 C and 1:1 water-to-crushed slag weight ratio. Thus obtained alumina-containing raw material contains, wt %: alumina 55-80, silica 6-14, aluminum metal up to 8, ferric oxide 4-10, magnesium oxide 2-10, sodium and potassium chlorides up to 3. EFFECT: improved environmental condition, quality of flux and alumina-containing raw material. 2 cl
