PROCEDE DE REDUCTION DIRECTE DE MATIERES CONTENANT DE L'OXYDE DE FER AU FOUR TUBULAIRE ROTATIF

a. Procédé de réduction directe de matières contenant de l'oxyde de fer au four tubulaire rotatif. b. Dans la zone de chauffage qui commence avec l'apparition de particules d'agent réducteur solide susceptibles d'être allumées et qui se termine en amont de la zone de réduction, on insuffle en des quantités réglées des gaz contenant de l'oxygène à l'aide d'ajutages dans le chargement se trouvant au-dessus des ajutages et on insuffle en des quantités réglées dans l'espace libre du four des gaz contenant de l'oxygène à l'aide de tubes de chemisage. c. Traitement du minerai de fer. A process for directly reducing iron oxide-containing materials to provide sponge iron by heating said iron oxide-containing materials in a rotary kiln while employing a solid carbonaceous reducing agent having a high content of volatile combustible components, wherein oxygen-containing gases are injected into the rotary kiln at a controlled rate through shell pipes into the free kiln space and the charge is moved through the rotary kiln countercurrently to the flow of the kiln atmosphere, is described. The invention lies in injecting oxygen-containing gases at controlled rates through nozzle blocks into the charge disposed over said nozzle blocks and in injecting oxygen-containing gases at controlled rates through shell pipes into the free kiln space in that region of the heating-up zone defined by a point along the length of the heating-up zone where ignitable particles of the solid reducing agent first appear and a second point before the reducing zone.