ORALS

SESSION: IronThuPM2-R8	Usui International Symposium on Advanced Sustainable Iron and Steel Making (7th Intl. Symp. on Advanced Sustainable Iron and Steel Making)
Thu Oct, 24 2019 / Room: Ambrosia B (77/RF)
Session Chairs: Moritoshi Mizutani; Shunsuke Hori; Session Monitor: TBA

16:45: [IronThuPM211] Invited
Effect of Ore Contraction Behavior on Permeability of Coke Slit Layer in Cohesive Zone
Kazuhira Ichikawa¹ ; Toshiyuki Hirosawa² ; Takeshi Sato³ ; Taihei Nouchi³ ; Kiyoshi Fukada² ; ¹, Chiba, Japan; ²JFE Steel Corporation, Fukuyama, Japan; ³JFE Steel Corporation, Chiba, Japan;
Paper Id: 87 [Abstract]

Recently, due to increases in the price of ironmaking coal, low coke rate operations in the blast furnaces have been necessary. Because coke works as a spacer in the blast furnace, however, low coke ratio operation causes deterioration of furnace permeability [1]. This is remarkable in the cohesive zone. The results of measurements of the shape of the cohesive zone in dissected blast furnaces revealed that the ore layer and coke slit layer were alternately layered [2]. Therefore, in the cohesive zone, gas is expected to flow horizontally along the coke slit layer. Thus, the permeability of the coke slit layer in cohesive zone is important. The authors developed a new simulator called the Cohesive Zone Simulator for quantifying the effect of the coke slit layer thickness on permeability. The authors revealed that this is because of the decrease in void fraction of the coke slit layer, caused by the increasing thickness of the penetration layer of melting the ore layer [3]. On the other hand, the effect of ore melting behavior on the permeability of the coke slit layer was not studied enough. Ore properties, i.e. reduction ratio and effect on the melting behavior, however, are known [4]. Based on the background outlined above, the effects of the contraction ratio of the melting ore layer to permeability were studied by using the cohesive zone simulator.

References:
[1] M.Ichida, S.Matsuzaki, T.Tanaka and F.Koizumi: Tetsu-to-Hagane, 87(2001), 342.\n[2] Y.Togino, M.Sugata, I.Abe and M.Nakamura: Tetsu-to-Hagane, 65(1979), 1526.\n[3] K.Ichikawa, Y.Kashihara, N.Oyama, T.Hirosawa, J.Ishii, M.Sato and H.Matsuno: Tetsu-to-Hagane, 102(2016), 1.\n[4] T.Nishimura, K.Higuchi, K.Ohno and K.Kunitomo: Tetsu-to-Hagane, 102(2016), 61.

SESSION: IronFriPM2-R8	Usui International Symposium on Advanced Sustainable Iron and Steel Making (7th Intl. Symp. on Advanced Sustainable Iron and Steel Making)
Fri Oct, 25 2019 / Room: Ambrosia B (77/RF)
Session Chairs: Taichi Murakami; Cyro Takano; Session Monitor: TBA

15:55: [IronFriPM209] Plenary
Evaluation of Ferro-coke Reaction Behavior in Blast Furnace
Yuki Iwai¹ ; Hideki Fujimoto² ; Takashi Anyashiki² ; Takeshi Sato³ ; Michitaka Sato² ; ¹JFE Steel Corporation, Fukuyama, Japan; ²JFE Steel, Fukuyama, Japan; ³JFE Steel Corporation, Chiba, Japan;
Paper Id: 419 [Abstract]

In recent years, development of innovative energy saving technologies for preventing global warming becomes more important for the steel industry. Ferro-coke is an innovative ironmaking process for energy saving in terms of realizing the low reducing agent ratio (RAR) operation in the blast furnace. In the Ferro-coke process, coal and iron ore were mixed and formed by a briquetting machine, and carbonized in a vertical type carbonization furnace. Ferro-coke causes lower thermal reserve zone temperature in a blast furnace because of its high gasification reactivity by Fe catalytic effect. In this study, the reactivity of ferro-coke was measured under the condition simulated a blast furnace. As a result, it was found that ferro-coke has remarkably higher reactivity and lower reaction starting temperature than normal coke and in the case of mixing sinter, the reduction of sinter was enhanced. In the former NEDO project, 2000 ton of ferro-coke was produced by the pilot plant with a capacity of 30 ton/day and the effect on RAR was confirmed in the actual blast furnace. For the next step, NEDO began the project “Environmentally Harmonized Steelmaking Process Technology Development (Ironmaking Process Technology Using Ferro-coke)” with a 6 year schedule from FY 2017. In this project, a ferro-coke production technology is to be established through a medium-scale plant producing 300 ton/day of ferro-coke with the aim of a 10% reduction in energy consumption in the ironmaking process by around the year 2022.