A Kinetic Study on Carbothermic Reduction of Hematite with Graphite Employing Thermogravimetry and Quadruple Mass Spectrometry. Issue 9 (12th March 2013)

• Record Type: Journal Article
• Authors: Jung, Sung‐Mo; Yi, Sang Ho
• Is Part Of: Steel research international. Volume 84:Issue 9(2013:Sep.)
• Page Start: 908
• Page End: 916
• Publication Date: 2013-03-12
• Subjects: carbon gasification -- direct reduced iron (DRI) -- quadruple mass spectrometry (QMS) -- rate‐controlling step -- thermogravimetric analysis; Steel -- Periodicals; Steel -- Metallurgy -- Periodicals; 669.142
• DOI: 10.1002/srin.201200310
• Languages: English
• ISSNs: 1611-3683

Abstract

Abstract: The reduction of hematite–graphite pellet was investigated from a kinetic viewpoint in the temperature range of 1173–1473 K (900–1200°C). The experimental procedure included thermogravimetric analysis (TGA) for measuring the weight change of the pellet and quadruple mass spectrometry (QMS) for monitoring the compositional change of the product gases. By applying a uniform internal reduction model to the current system, the activation energies for the reduction of Fe3 O4 to wustite and for that of wustite to Fe were evaluated to be 91.0 and 25.9 kJ mol −1, respectively. Due to the product gas analyses by QMS, it was observed that the reduction rate of hematite–graphite pellet was accelerated up to the equilibrium concentration of CO determined by the carbon gasification curve. Changeover of reduction mechanism with increasing reduction degree was explained in terms of a schematic diagram based on the results obtained in the current study. Abstract : Recently, great attention has been paid to the technology of direct reduced iron (DRI) production using low grade of ores and noncoking coals for alternative iron source. The carbothermic reduction of hematite in an Ar atmosphere has been investigated by employing thermogravimetry and quadruple mass spectrometry (QMS) gas analysis with the intention of understanding in detail the reduction phenomena of carbon composite iron ore agglomerates in the rotary kilns.