Process for treating metal oxide fines

A process for treating metal oxide fines to recover elemental iron from iron-bearing materials including iron-bearing ores, steel mill waste and other metallurgical process waste, the process comprising the steps of:

• a) providing a mixture of iron-bearing materials having iron oxides and oxides of zinc cadmium and lead therein and carbonaceous material containing less than about 20 wt. % volatile matter;
• b) blending an organic binder with the mixture;
• c) agglomerating the mixture to form green compacts;
• d) loading the green compacts into a zone of a preheated rotary hearth furnace, the rotary hearth furnace having a loading zone for receiving the green compacts, a reduction zone for reducing the compacts, and a discharge zone for discharging the reduced compacts;
• e) introducing preheated combustion air and an external fuel throughout the length of the furnace;
• f) heating the green compacts for about 5 to 12 minutes at a temperature of between about 2200-2500° F. and at a CO/CO2 ratio of between about 1.5-2.5 in the reduction zone to reduce the compacts and evolve undesirable oxides from the compacts;
• and
• g) discharging the reduced compacts from the rotary hearth furnace to a soaking pit at a temperature sufficient to complete the reduction of the iron oxide and remove over 99% of the zinc, cadmium and lead oxides from the compacts to provide a compact containing elemental iron and about 2-10 wt. % carbon.