METHOD OF ALUMINOTHERMIC REFINING OF DUST-LIKE ZINC DROSS FRACTION Russian patent published in 2000 - IPC

FIELD: nonferrous metallurgy. SUBSTANCE: aluminum is melted in melting unit crucible at aluminum-to-dross ratio 1:(4-5), after which flux with melting point by 210-280 C superior to melting point of zinc is scattered (poured) onto its surface to form a layer with height 0.2-0.3 that of crucible height. Introduction of dust-like zinc dross fraction is accomplished by admixing it to flux at 720-760 C. As working space of crucible is filled with metal and flux melts, temperature is lowered to 430-500 C and the total is allowed to stand for 0.4 to 12 h. Before settling, a portion of aluminum cuttings is added to flux in quantity corresponding to 1-3% of the metal melt weight in order to reduce residual zinc in flux. EFFECT: increased yield of valuable product at lower cost. 3 cl, 1 tbl