2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 6: Yagi Intl. Symp. / Metals & Alloys Processing
| Editors: | Kongoli F, Akiyama T, Nogami H, Saito K, Fujibayashi A |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 480 pages |
| ISBN: | 978-1-987820-46-1 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
CD shopping page
Acceleration Mechanism of Reduction of Iron Ore-Carbon Composite by Increasing Pressure
Taichi Murakami1; Hiroyuki Nagashima1; Qi Zhou1; Eiki Kasai2;1TOHOKU UNIVERSITY, Sendai, Japan; 2GRADUATE SCHOOL OF ENVIRONMENTAL STUDIES, TOHOKU UNIVERSITY, Sendai, Japan;
Type of Paper: Keynote
Id Paper: 61
Topic: 3
Abstract:
Utilization of iron ore-carbon composite enables to play a significant role in reducing CO2 emission from the ironmaking process. However, its efficiency seems to be limited under the condition of the blast furnace. In this study, the effect of pressure from 0.1 to 8.0 MPa on the gasification and reduction of the composite was evaluated, and acceleration mechanism of reduction was discussed by mathematical simulation. The composite sample prepared using hematite reagent and graphite powder was heated up to different target temperatures at a heating rate of 0.167 ºC/s under different pressures. Under atmospheric pressure, reduction of composite sample started at approximately 900 ºC and completed at 1200 ºC. Starting temperature of reduction decreased with increasing pressure. At 1050 ºC, the effect of pressure on the reduction was most significant because gasification of graphite activated. To discuss the behavior, a mathematical simulation was carried out using Langmuir-Hinshelwood type gasification and unreacted-core models assuming that the temperature distribution in the composite sample can be neglected. Using the experimental data under atmospheric pressure, all parameters were decided, and the effect of pressure on the reduction was evaluated. Below 3.0 MPa, the calculated results were coincident with the measured one. It seems that reduction acceleration by increasing pressure is caused by an increase in the amount of adsorbed CO and O on carbon. Above 5.0 MPa and 1000 ºC, however, the latter was higher than the former. The reason may be that the temperature distribution cannot be neglected under higher pressure.
Keywords:
CO2; Composite; Iron;References:
[1] M. Kundak, L. Lazić and J. Črnko: CO2 Emissions in the Steel Industry, Metalurgija, 48(2009), 193-197[2] S. Watakabe, K. Takeda, H. Nishimura, S. Goto, N. Nishimura, T. Uchida and M. Kiguchi: Development of High Ratio Coke Mixed Charging Technique to the Blast Furnace, Tetsu-to-Hagané, 92 (2006), 901-910
[3] A. Kasai, M. Naito, Y. Matsui and Y. Yamagata: Reduction and Carburization of Carbon Composite Iron Ore Hot Briquet on Condition of Increasing in Temperature, Tetsu-to-Hagané, 89 (2003), 1212-1219
[4] W. M. Mckewan: Reduction Kinetics of Magnetite in Hydrogen at High Pressures, Trans. Met. Soc. AIME, 224 (1962), 387-393
[5] S. Kurozu, R. Takahashi and Y. Takahashi: Reduction Rates of Iron Oxide Pellet with Hydrogen at High Pressures, Tetsu-to-Hagané, 66 (1980), 23-32
[6] Y. Ueda, K. Sato, Y. Nishikawa, Y. Suzuki, S. Sayama and T. Sato: Hydrogen Reduction of Pulverized Iron Ore by High Pressure Fluidized Bed, Tetsu-to-Hagané, 67(1981), 1925-1933
[7] Y. Suzuki, S. Sayama, Y. Nishikawa, Y. Ueda, K. Sato and T. Sato: Correlation of Kinetic Parameters of High Pressure Reduction of Iron Ore Examined with 8mm and 60mm Fluidized Bed Reactor, Tetsu-to-Hagané, 68(1982), 930-935
[8] E. Kasai, K. Mae and F. Saito: Effect of Mixed-grinding on Reduction Process of Carbonaceous Material and Iron Oxide Composite, ISIJ Int., 35 (1995), 1444-1451
[9] S. Ueda, K. Yanagiya, K. Watanabe, T. Murakami, R. Inoue, and T. Ariyama: Reaction Model and Reduction Behavior of Carbon Iron Ore Composite in Blast Furnace, ISIJ Int., 49(2009), 827-836
[10] J. D. Blackwood and A. J. Ingeme: The Reaction of Carbon with Carbon Dioxide at High Pressure, Aust. J. Chem. 13(1960), 194-209
[11] F. Meng, Y. Iguchi and S. Hayashi: Tetsu-to-Hagané, 88(2002), 479-486
[12] T. Murakami, T. Nishimura, N. Tsuda and E. Kasai: Quantitative Analysis on Contribution of Direct Reduction of Iron Oxide in Carbon Composite, ISIJ Int., 53(2013), 1763-1769