Abstract: A method and means for maximizing the use of the kiln capacity in a rotary kiln, directly reducing metal oxides using solid carbonaceous materials as the source of fuel and reducant, is disclosed involving the creation of an annular dam arrangement within the kiln at a selected position between the feed end and the discharge end dams, which arrangement is located and dimensioned with respect to the end dams, such that the materials in the charge bed suitably fill the kiln volume and have sufficient residence time in the feed end portion of the kiln, to permit adequate heat transfer thereto, thus minimizing the portion of the kiln needed for preheating and maximizing the remaining portion of the kiln available for reduction.

Abstract: A method and means for improved control of the process for directly reducing materials containing iron oxides in a rotary kiln using a solid carbonaceous reducing agent, such as coal, introduced from the charge feed and discharge ends of the kiln, as the source of both fuel and reductant, and oxygen-containing gas introduced along the kiln length, is disclosed wherein the portion of the reducing agent fed at the discharge end is injected in the form of two or more streams through the discharge end of the kiln onto the charge bed in such manner as to permit close and efficient control of the process, particularly when carried out in larger kilns.