Process of directly reducing iron oxide containing materials in a rotary kiln

US4369059A · kind A · utility

Assignee

• Metallgesellschaft AG · DE

Inventors

• Gerd Elsenheimer · Frankfurt am Main, DE
• Wolfram Schnabel · Idstein, DE

Key dates

• Filing date: Jan 21, 1981
• Grant date: Jan 18, 1983
• Expiry date: Jan 21, 2001

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/134
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Before iron oxide-containing materials is reduced in a rotary kiln by a treatment with solid carbonaceous reducing agents below the melting point of the charge, the iron oxide containing material and carbonaceous reducing agent are preheated in a multiple-hearth furnace, in which the reducing agent is subjected to an at least partial coking or an at least partial low-temperature carbonization. To prevent a partial reduction and sintering, the iron oxide-containing material is preheated in the upper part of the multiple-hearth furnace and the solid carbonaceous reducing agent is separately preheated in the lower part of the multiple-hearth furnace. At least part of the gases produced by the low-temperature carbonization in the lower part of the multiple-furnace is caused to flow in the upper part of said furnace in a countercurrent to the iron oxide-containing material to supply the heat required in said upper part.