Direct reduction of iron oxide materials with solid carbonaceous reducing agents

US5433767A · kind A · utility

Assignee

• Metallgesellschaft AG · DE

Inventors

• Wolfgang Bresser · Großostheim, DE
• Martin Hirsch · Friedrichsdorf, DE
• Bernd Kosters · Frankfurt am Main, DE
• Fritz Rose · Bad Homburg vor der Höhe, DE

Key dates

• Filing date: Mar 9, 1994
• Grant date: Jul 18, 1995
• Expiry date: Mar 9, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

In a first fluidized bed vessel containing an expanded fluidized bed, iron oxide-containing materials are reduced under weakly reducing conditions with solid carbonaceous reducing agents to or to less than the FeO state. In a second fluidized bed vessel containing an expanding fluidized bed the gas-solids suspension discharged from the first fluidized bed vessel is treated with a highly reducing fluidizing gas whereby the material is reduced in part to iron metal. From the gas-solid suspension discharged from the second fluidized bed vessel the carbonized carbonaceous material is separated and is recycled to the first fluidized bed vessel. The exhaust gas from which the carbonized carbonaceous material has been removed is purified and CO.sub.2 is removed therefrom and the exhaust gas is subsequently fed as a fluidizing gas to the second fluidized bed vessel. A reduced material which has a degree of metallization from 50 to 80% and the remainder of the carbonized carbonaceous material are discharged from the second fluidized bed vessel and in a melting reactor are completely reduced and melted.