VERFAHREN UND VORRICHTUNG ZUR DIREKTREDUKTION VON METALLOXYDEN

A method and apparatus is disclosed for direct reduction of metal oxides, using a rotary kiln, fed with greenball pellets, the kiln having a feed-end and a discharge end. A first chamber within the kiln, and adjacent to the feed-end, is used for drying, preheating and indurating the greenball pellets. Greenball pellets are fed into the first chamber using a conventional mechanism. The feed-end is sealed to prevent egress of process gas from the kiln into the atmosphere and ingress of the atmosphere into the kiln. A first burner is used for drying, preheating and indurating the greenball pellets within the first chamber. A second chamber within the kiln, adjacent to and connected with the first chamber, having a diameter greater than the first chamber, is used for reducing the pellets, the second chamber being adjacent to the discharge end. A second burner may be used for reducing the pellets within the second chamber. Reduced pellets are discharged from the discharge end. The axial angle of the kiln is varied to regulate the flow rate of the greenball pellets from the first chamber to the second chamber.