摘要
氨还原赤铁矿是一种潜在的环保炼铁方法,有利于解决氢的运输和储存所面临的物流和能源问题。然而,先前研究中氨还原球团矿的样品质量通常仅为2.8 g,且缺乏对氨氢共同还原球团矿活化能的讨论。为进一步分析NH_(3)-H_(2)还原球团矿的还原动力学,本文采用50 g球团矿进行还原试验,讨论NH_(3)-H_(2)还原球团矿过程中的动力学行为,并通过热力学与XRD分析研究球团矿NH_(3)-H_(2)还原过程中的相结构组成与变化。研究结果表明,使用100%NH_(3)还原50 g球团矿的速率低于50%NH_(3)与50%H_(2)的混合气体,而后者又低于100%H_(2)。随着温度的升高,50%NH_(3)与50%H_(2)对球团矿的还原效果逐渐接近于100%H_(2)。从常见的气固反应数学模型中选取相边界控制模型中的收缩圆柱模型作为最概然反应机理函数,对于还原50 g球团矿,使用100%NH_(3)、50%NH_(3)与50%H_(2)和100%H_(2)的还原反应活化能分别为65.42、54.37 kJ/mol和29.17 kJ/mol。NH_(3)的分解反应对Fe_(2)O_(3)的还原具有负面影响。热力学与XRD分析结果表明:100%NH_(3)还原Fe_(2)O_(3)过程中会伴随有少量Fe_(4)N生成;由于NH_(3)分压之间的差异,使用50%NH_(3)与50%H_(2)还原球团矿会大幅减少Fe_(4)N的生成。本文研究成果可拓展氨还原球团矿动力学研究范围,为后续的工业应用提供理论基础。
Ammonia-reduced hematite is a potential environmentally friendly ironmaking method,which is beneficial to solve the logistics and energy problems faced by the transportation and storage of hydrogen.However,the sample mass of ammonia-reducing pellets in previous researches is usually only 2.8 g,and there is a lack of discussion on the activation energy of ammonia-hydrogen co-reduced pellets.In order to further analyze the reduction kinetics of NH_(3)-H_(2) reduced pellets,50 g pellets are used for reduction experiments,and the dynamic behavior of NH_(3)-H_(2) reduced pellets is discussed,and the phase structure composition and changes of NH_(3)-H_(2) pellets are studied by thermodynamics and XRD analysis.The results show that the rate of reduction of 50 g pellets with 100%NH_(3) is less than that of a mixture of 50%NH_(3) and 50%H_(2),and the latter is less than 100%H_(2).With the increase of temperature,the reduction effect of 50%NH_(3) and 50%H_(2) on pellets gradually approaches 100%H_(2).The shrinkage cylindrical model in the phase boundary control model is selected as the most general reaction mechanism function from the common mathematical models of gas-solid reaction,and the activation energies of 100%NH_(3),50%NH_(3),50%H_(2) and 100%H_(2) are 65.42 kJ/mol,54.37 kJ/mol and 29.17 kJ/mol,respectively.The decomposition reaction of NH_(3) has a negative effect on the reduction of Fe_(2)O_(3).The results of thermodynamics and XRD analysis show that a small amount of Fe_(4)N is formed during the reduction of Fe_(2)O_(3) by 100%NH_(3),and the formation of Fe_(4)N is greatly reduced by reducing pellets with 50%NH_(3) and 50%H_(2) due to the difference between the partial pressure of NH_(3).The results can expand the research scope of ammonia reduction pellet dynamics and provide a theoretical basis for subsequent industrial applications.
作者
杨佳龙
米澳
张晓萍
从俊强
胡正洪
李家新
温宝良
YANG Jialong;MI Ao;ZHANG Xiaoping;CONG Junqiang;HU Zhenghong;LI Jiaxin;WEN Baoliang(School of Metallurgical and Engineering,Anhui University of Technology,Ma’anshan 243032,Anhui,China;Technology Center,Ma’anshan Iron and Steel Co.,Ltd.,Ma’anshan 243003,Anhui,China)
出处
《烧结球团》
北大核心
2025年第4期40-47,72,共9页
Sintering and Pelletizing
基金
安徽省重大产业创新计划资助项目(AHZDCYCX-LSDT2023-01)
国家自然科学基金青年基金资助项目(52204330)。
关键词
可持续炼铁
氨还原
氢还原
球团矿
还原动力学
sustainable ironmaking
ammonia reduction
hydrogen reduction
pellets
reduction kinetics
