TY - GEN
T1 - Reduction disintegration mechanism of iron ore sinter under high H 2 and H2o condition at 773K
AU - Murakami, Taichi
AU - Kamiy, Yousuke
AU - Kodaira, Takeyuki
AU - Kasai, Eiki
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Reduction of CO2 emission is recognized as an urgent issue in the iron and steel industry. One feasible method may be the utilization of H2 gas as a reducing agent in blast furnace (BF) ironmaking. In order to keep the BF condition stable under high H2 operation, it is necessary to understand the effect of H2 and H2O gas on the disintegration behavior of iron ore sinter in the upper part of a BF. Therefore, the reduction disintegration mechanism of iron ore sinter at 773 K under N2-CO-CO2- H2-H2O gas was evaluated. Reduction experiments were carried out under N2- 20%CO-20%CO2 (0% H2) and N2-12%CO-17.7%CO 2-8%H2-2.3%H2O (8% H2) using a 25 g sinter sample, varying the reduction time between 1.8 and 7.2 ks. Reduction degree of the sinter was calculated in terms of the mass difference between before and after the reduction. A tumbling drum test was carried out for 1.8 ks to evaluate the strength of the reduced sinter. Reduction degree of the sinter by 8% H2 gas steadily increased with time. On the other hand, it was retarded once when reduced under 0% H2. At the same reduction time, the reduction degree obtained by 0% H2 showed a lower value than that by 8% H2. At the same reduction degree, however, the RDI value of the sinter reduced by 0% H2 gas is higher than that by 8% H 2. This is because CO gas reduction proceeds mainly near the surface of the sinter particles, while H2 gas reduction tends to proceed inside the particles.
AB - Reduction of CO2 emission is recognized as an urgent issue in the iron and steel industry. One feasible method may be the utilization of H2 gas as a reducing agent in blast furnace (BF) ironmaking. In order to keep the BF condition stable under high H2 operation, it is necessary to understand the effect of H2 and H2O gas on the disintegration behavior of iron ore sinter in the upper part of a BF. Therefore, the reduction disintegration mechanism of iron ore sinter at 773 K under N2-CO-CO2- H2-H2O gas was evaluated. Reduction experiments were carried out under N2- 20%CO-20%CO2 (0% H2) and N2-12%CO-17.7%CO 2-8%H2-2.3%H2O (8% H2) using a 25 g sinter sample, varying the reduction time between 1.8 and 7.2 ks. Reduction degree of the sinter was calculated in terms of the mass difference between before and after the reduction. A tumbling drum test was carried out for 1.8 ks to evaluate the strength of the reduced sinter. Reduction degree of the sinter by 8% H2 gas steadily increased with time. On the other hand, it was retarded once when reduced under 0% H2. At the same reduction time, the reduction degree obtained by 0% H2 showed a lower value than that by 8% H2. At the same reduction degree, however, the RDI value of the sinter reduced by 0% H2 gas is higher than that by 8% H 2. This is because CO gas reduction proceeds mainly near the surface of the sinter particles, while H2 gas reduction tends to proceed inside the particles.
KW - Crack density
KW - Disintegration
KW - Hematite
KW - Hydrogen
KW - Magnetite
KW - Reduction
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M3 - Conference contribution
AN - SCOPUS:84883669166
SN - 9781627480215
T3 - 6th Int. Congress on the Science and Technology of Ironmaking 2012, ICSTI 2012 - Including Proceedings from the 42nd Ironmaking and Raw Materials Seminar, and the 13th Brazilian Symp. on Iron Ore
SP - 1225
EP - 1232
BT - 6th Int. Congress on the Science and Technology of Ironmaking 2012, ICSTI 2012 - Including Proceedings from the 42nd Ironmaking and Raw Materials Seminar, and the 13th Brazilian Symp. on Iron Ore
T2 - 6th International Congress on the Science and Technology of Ironmaking 2012, ICSTI 2012
Y2 - 14 October 2012 through 18 October 2012
ER -