METHOD AND APPARATUS FOR DIRECT REDUCTION OF A MATERIAL CONTAINING IRON OXIDE IN A PARTICULATE FORM

• Main Authors: REIDETSCHLAGER, JOHANN, SCHENK, JOHANNES, MILIONIS, KONSTANTIN, KEPPLINGER, LEOPOLD WERNER, WHIPP, ROY HUBERT JR, ZIRNGAST, JOHANN, ZELLER, SIEGFRIED
• Format: Patent
• Language: English; French
• Published: 27.04.2010
• Subjects: CHEMISTRY; MANUFACTURE OF IRON OR STEEL; METALLURGY; METALLURGY OF IRON

The present invention relates to a method that uses fluidised bed techniques for the direct reduction of a material containing iron oxide in a particulate form. According to the method of the present invention, a synthetic gas used as reducing gas is fed into a plurality of fluidised bed areas which are arranged serially one after the other for receiving said gas, wherein said gas is fed from one fluidised bed area to the other in a direction opposite to that of the material containing iron oxide in a particulate form. In order to reduce the operation costs and more particularly the power consumption, the temperature of the material containing iron oxide in the first fluidised bed area is set at a value lower than 400 °C, preferably lower than 350 °C, or at a value exceeding 580 °C, preferably about 650 °C, or else in a range of between 400 °C and 580 °C. When the temperature is set at a value lower than 400 °C, the temperature range of between 400 °C and 580 °C in the fluidised bed area located downstream form the first area in the flow direction of the material containing iron oxide is exceeded within 10 minutes and preferably 5 minutes. When the temperature is set at a value exceeding 580 °C, the temperature range of between 400 °C and 580 °C is exceeded within 10 minutes and preferably 5 minutes. When the temperature is set in the range of between 400 °C and 580 °C, the material containing the iron oxide is kept within this range of temperature for a duration not exceeding 10 minutes, preferably 5 minutes. Immediately after the target temperature is reached, the material containing the iron oxide is transferred into the next fluidised bed area.