METHOD FOR PROCESSING ALUMINIUM WASTES Russian patent published in 1995 - IPC

FIELD: production of aluminum. SUBSTANCE: method for processing aluminum wastes includes deposition of molten salt fluxes, introduction into salt melt at 690-750 C of aluminum wastes, their melting with stirring and saturation of salt melt with solid inclusions, separate tapping of metal and salt, separation of solid inclusions from salt melt with its subsequent direction for processing new lot of wastes. Solid inclusions are separated from salt melt by centrifugal filtration on slotted centrifuges. Solid inclusions are separated, either, directly in remelting furnace before or after tapping of metal, or during tapping of salt melt from furnace, or in mixer-fore-hearth after tapping into it of salt melt from remelting furnace. Aluminum wastes are melted at salt melt-to-aluminum wastes mass ratio of (1.5-2.5):1. Supply of aluminium wastes into salt is accomplished when salt melt is rotated by any known method to form funnel on the surface of melt. Funnel depth equals 0.05-0.15 diameter of crucible for waste melting. In case of separation of solid inclusions in remelting furnace or in mixer-forehearth, operation is carried out with use of immersion centrifuge. In so doing, filtration is effected with separation factor of 5-50, and centrifuging, with separation factor of 100-300. When solid inclusions are separated during overflow of salt melt, operation is carried out with application of special centrifuge with separation factor of 80-350. In this case, separation factor is uniformly increased from 80 at the beginning of the process up to 350 in the end of filtration. EFFECT: higher recovery of metal, reduced consumption of salt flux and decreased amount of wastes. 8 cl, 1 tbl