摘要
氢等离子熔融还原作为下一代氢冶金CO_(2)减排新技术受到广泛关注。以铁矿氧化球团为试验原料,系统地研究了气体流量和还原时间对氢等离子熔融还原过程的影响(气体流量为5、8、10 L/min,H_(2)的体积分数为10%),为氢等离子熔融还原铁矿氧化球团的研究提供理论依据。通过X射线粉末衍射、Rietveld精修、扫描电子显微镜和化学分析对铁矿氧化球团还原动力学、含铁物相演变、微观结构及生铁中杂质含量进行研究。结果表明,铁矿氧化球团最大转化速率从气体流量为5 L/min时的1.05 g/min升高至气体流量为8 L/min时的3.60 g/min,而继续增大气体流量至10 L/min,最大转化速率反而有所下降。氢等离子熔融还原符合相边界反应模型,其机理函数为f(α)=3(1-α)^(2/3)(α为铁转化率),不同气体流量下对应的反应速率常数分别为2.12×10^(-4)、7.29×10^(-4)、6.62×10^(-4)s^(-1),表观活化能约为21 kJ/mol,反应速率方程为ln r=-0.18-2856/T(r为比还原速率,T为反应温度)。铁矿氧化球团还原反应过程为Fe_(2)O_(3)→Fe_(3)O_(4)→Fe_(x)O→Fe_(2)SiO_(4)→Fe,完全还原后,生铁的纯度可达到3N级工业纯铁水平。
Hydrogen plasma smelting reduction has received wide attention as a new technology for CO_(2)reduction in next-generation hydrogen metallurgy.The effects of gas flow rate and reduction time on the hydrogen plasma smelting reduction process(gas flow rates 5,8,10 L/min,H_(2)volume fraction 10%)were systematically investigated using iron ore oxidized pellet as the experimental material to provide theoretical basis for the hydrogen plasma smelting reduction of iron ore oxidized pellet.The reduction kinetics,evolution of Fe-containing phases,microstructure and impurity content in pig iron were investigated by X-ray powder diffraction,Rietveld refinement,scanning electron microscopy and chemical analysis.The results show that the maximum conversion rate of iron oxidized pellet increases from 1.05 g/min at gas flow rate of 5 L/min to 3.60 g/min at gas flow rate of 8 L/min,while continue to increase the gas flow rate to 10 L/min,the maximum conversion rate decreases.The hydrogen plasma smelting reduction is consistent with the phase boundary reaction model with the mechanism function f(α)=3(1-α)^(2/3),αis conversion ratio of iron,and the corresponding reduction rate constants at different gas flow rate are 2.12×10^(-4),7.29×10^(-4),and 6.62×10^(-4)s^(-1),respectively.Apparent activation energy is about 21 kJ/mol,reaction rate equation is ln r=-0.18-2856/T,r is specific reduction rate,T is reaction temperature.The process of iron ore oxidized pellet reduction reaction is Fe_(2)O_(3)→Fe_(3)O_(4)→Fe_(x)O→Fe_(2)SiO_(4)→Fe.After complete reduction,the purity of pig iron can reach 3N grade of industrial pure iron.
作者
杨智文
余建波
张一帆
王江
任忠鸣
YANG Zhiwen;YU Jianbo;ZHANG Yifan;WANG Jiang;REN Zhongming(State Key Laboratory of Advanced Special Steel,Shanghai 200444,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)
出处
《中国冶金》
CAS
CSCD
北大核心
2023年第12期31-41,共11页
China Metallurgy
基金
国家科技重大专项资助项目(J2019-Ⅵ-0023)
上海市科委扬帆计划资助项目(21YF1413000)。
