摘要 |
When in the direct reduction of iron-oxide-containing materials in a rotary kiln solid, carbonaceous reducing agents having a high content of volatile constituents are charged to the rotary kiln at its charging end, a reoxidation of the sponge iron can readily occur in the final portion of the reduction zone unless a definite surplus of solid reducing agent is there maintained. To reduce the required surplus while still positively avoiding reoxidation, reducing gases and/or liquid hydrocarbons are introduced in said final portion by means of tubular air nozzles at least partially into the charge located above the air nozzles beginning with at least 75 percent metallization. |