Process for separating iron from other metals in iron containing feed stocks

A method of separating iron from zinc and other metals in iron and zinc containing feed stocks comprising the steps of:

• reduction roasting the feed stocks at a volatizing temperature sufficient to volatilize the other metals into metal fumes but insufficient to volatize iron;
• collecting the metal fumes as a metal dust;
• leaching the metal dust with a leaching liquid to form a leach liquor and a leach residue;
• purifying the leach liquor using zinc dust cementation to form a purified liquor and a zinc dust cement residue;
• separating the purified liquor from the zinc dust cement residue, and
• subjecting the purified liquor to a zinc recovery step.

A method of separating iron from zinc and other metals in iron and zinc containing feed stocks comprising the steps of:

• water washing the iron and zinc containing feed stocks and then leaching the washed feed stocks with a preliminary leach liquid to form a preliminary leach residue and a preliminary leach liquor, separating the preliminary leach liquor from the preliminary leach residue, water washing the preliminary leach residue, mixing the washed preliminary leach residue with a feed stock mixture to form a treated mix, the feed stock mixture selected from the group consisting of BOF sludge, mill scale, tire dust, pellet fines and sinter fines;
• reduction roasting the treated mix at a volatizing temperature sufficient to volatilize the other metals into metal fumes but insufficient to volatize iron;
• collecting the metal fumes as a metal dust;
• leaching the metal dust with the preliminary leach liquor to form a second leach liquor and a second leach residue;
• purifying the second leach liquor using zinc dust cementation to form a purified liquor and a zinc dust cement residue;
• separating the purified liquor from the zinc dust cement residue, and
• subjecting the purified liquor to a zinc recovery step.