1 School of Metallurgical Engineering, Anhui University of Technology, Ma’anshan 243002, Anhui, China 2 Key Laboratory of Metallurgical Emission Reduction and Resources Recycling Anhui University of Technology, Ministry of Education, Ma’anshan 243002, Anhui, China 3 Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 3K7, Canad
Effects of gangue compositions on reduction process of carbon-bearing iron ore pellets
1 School of Metallurgical Engineering, Anhui University of Technology, Ma’anshan 243002, Anhui, China 2 Key Laboratory of Metallurgical Emission Reduction and Resources Recycling Anhui University of Technology, Ministry of Education, Ma’anshan 243002, Anhui, China 3 Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 3K7, Canad
摘要 The influence of gangue compositions (mainly composed of SiO2, CaO, MgO and Al2O3) on the reduction kinetics of carbon-bearing iron ore pellets was estimated at 1373–1473 K in N2 atmosphere. The results showed that gangue content and each component distribution affected the pellets reduction process. The reduction rate was found to follow a linear correlation with quaternary basicity R4 [mass ratio of (CaO+MgO) to (SiO2+Al2O3)] of the carbon-bearing iron ore pellets; also, the content of SiO2 solid solution in iron oxide had a significant impact on the reduction rate. At the same reduction temperature, a higher R4 resulted in a lower SiO2 free content, weakening its inhibitory effect on the Boudouard reaction. The reduction temperature of Fe2SiO4 could be reduced by increasing the contents of CaO and MgO, improving the iron oxide reduction as well as the precipitation and growth of the iron grains. The gangue content and component distribution showed no effect on the rate-controlling step of the reduction; however, the apparent activation energy of reaction decreased with increasing quaternary basicity. When R4 increased from 0.15 to 0.67, the apparent activation energy decreased from 228.51 to 193.66 kJ/mol.
Abstract:The influence of gangue compositions (mainly composed of SiO2, CaO, MgO and Al2O3) on the reduction kinetics of carbon-bearing iron ore pellets was estimated at 1373–1473 K in N2 atmosphere. The results showed that gangue content and each component distribution affected the pellets reduction process. The reduction rate was found to follow a linear correlation with quaternary basicity R4 [mass ratio of (CaO+MgO) to (SiO2+Al2O3)] of the carbon-bearing iron ore pellets; also, the content of SiO2 solid solution in iron oxide had a significant impact on the reduction rate. At the same reduction temperature, a higher R4 resulted in a lower SiO2 free content, weakening its inhibitory effect on the Boudouard reaction. The reduction temperature of Fe2SiO4 could be reduced by increasing the contents of CaO and MgO, improving the iron oxide reduction as well as the precipitation and growth of the iron grains. The gangue content and component distribution showed no effect on the rate-controlling step of the reduction; however, the apparent activation energy of reaction decreased with increasing quaternary basicity. When R4 increased from 0.15 to 0.67, the apparent activation energy decreased from 228.51 to 193.66 kJ/mol.
MENG Qiang-Min,LI Jia-Xin,WEI Ru-Fei, et al. Effects of gangue compositions on reduction process of carbon-bearing iron ore pellets[J]. Journal of Iron and Steel Research International, 2018, 25(11): 1105-1112.