铁精粉单颗粒高温还原过程中的演化特征

孙爽; 沈中杰; 朱玉龙; 梁钦峰; 刘海峰

doi:10.14135/j.cnki.1006-3080.20201127006

铁精粉单颗粒高温还原过程中的演化特征

doi: 10.14135/j.cnki.1006-3080.20201127006

华东理工大学上海煤气化工程技术研究中心，上海 200237

基金项目: 国家自然科学基金青年基金项目（21908063）；中央高校基本科研业务费专项资金（222201814052）

详细信息

作者简介:
孙爽：孙　爽（1996—），男，硕士生，研究方向为高温气固反应

通讯作者:
沈中杰，zjshen@ecust.edu.cn

中图分类号: TF557
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- 被引次数: 0
出版历程
- 收稿日期: 2020-11-27
- 网络出版日期: 2021-01-07

Evolution Characteristics of Single Iron Concentrate Particle During the High-Temperature Reduction Process

Shanghai Engineering Research Center of Coal Gasification, East China University of Science and Technology, Shanghai 200237, China

摘要

摘要: 采用高温热台显微镜原位研究了铁精粉单颗粒在高温及CO气氛下还原过程的演化特征。通过原位实验记录了铁精粉单颗粒的高温还原过程，并利用拉曼光谱仪验证了还原反应产物（单质铁）。结果表明，颗粒表面出现单质铁的时间受温度影响显著，气体流量影响小。其中，单质铁的生成时间从1 100 ℃至1 300 ℃减小约75%，温度从1 300 ℃至1 400 ℃，单质铁生成时间基本不变。铁精粉颗粒在1 100 ℃到1 350 ℃之间还原过程中表面会产生瘤状物，且瘤状物尺寸随着温度升高而增大，引入长宽和平均值为特征尺度l，l由1 100 ℃的6 μm增至1 350 ℃的15 μm。还原温度大于1 400 ℃时，铁精粉颗粒出现熔融态的产物分层现象：内层为还原铁，中层为熔融氧化亚铁被还原的树根状金属铁，外层为含有Al、Ca和Si等元素集聚的铁渣。
- 铁精粉 /
- 高温还原 /
- 颗粒演化 /
- 一氧化碳 /
- 显微结构
Abstract: The evolution characteristics of the reduction process of single iron concentrate particles under high temperature and CO atmospheres were studied in the in-situ experiment of a high temperature stage microscope. The high-temperature reduction process of single iron concentrate was recorded via in-situ experiment, and the reduced product (elemental iron) was verified by using Raman spectrometer. The results showed that the initial formation time of the elemental iron on the particle surface was mainly affected by temperature, and this influence from the gas flowrate was smaller. The initial formation time decreased 75% when the reducing temperature reduced from 1 100 ℃ to 1 300 ℃. But a unchanged result of this formation time was found in the temperature range from 1 300 ℃ to 1 400 ℃. Nodular structures were found on the surface of iron concentrate particles during the reduction process between 1 100 ℃ and 1 350 ℃, and their sizes increased with the rising reduction temperature. A characteristic number l, which was self-defined as the mean value of the length and width, increased from 6 μm at 1 100 ℃ to 15 μm at 1 350 ℃. When the reduction temperature was above 1 400 ℃, layered melting products were observed for the iron concentrate particle: the product on the core is reduced iron, the second layer was the root-shaped metal iron with reduced molten ferrous oxide, and the outer layer was the iron slag containing Al, Ca, Si, and other elements.
- iron concentrate particle /
- high temperature reduction /
- particle evolution /
- CO /
- microstructure

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图 1 铁精粉XRD

Figure 1. XRD of iron concentrate powder

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图 2 高温热台结构图

Figure 2. Structure diagram of HTSM

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图 3 1 300 ℃和1 100 ℃下200 mL/min还原10 min后与反应前拉曼对比图

Figure 3. Comparison of Raman after and before reduction at 1 300 ℃ and 1 100 ℃ at 200 mL/min for 10 min

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图 4 不同温度下CO（200 mL/min）还原铁精粉的过程

Figure 4. Process of reducing iron concentrate particle by CO (200 mL/min) at different temperatures

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图 5 铁精粉颗粒在不同的CO流量下生成单质铁随的温度变化

Figure 5. Change of elemental iron produced by iron concentrate particles with temperature under different CO flow rates

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图 6 1 400 ℃反应后铁精粉颗粒SEM-EDS

Figure 6. SEM-EDS of fine iron powder particles after reaction at 1 400 ℃

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图 7 1 400 ℃熔融部分面扫描

Figure 7. Melting part surface scanning of 1 400 ℃

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图 8 铁精粉颗粒在不同温度下SEM-EDS

Figure 8. SEM-EDS of fine iron concentrate particles at different temperatures

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图 9 瘤状物特征尺度在不同气量下随温度变化图

Figure 9. Characteristic scale of nodules varies with temperature under different air volumes

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图 10 低温（1 100 ~1 350 ℃）下铁精粉单颗粒还原生成铁单质的结构变化图

Figure 10. Structure change diagram of single-particle reduction of iron fine powder at low temperature (1 100 ~1 350 ℃)

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图 11 高温（1 400 ℃以上）下铁精粉单颗粒还原生成铁单质的结构变化图

Figure 11. Structure change diagram of iron concentrate particle reduction of iron fine powder at high temperature (above 1 400 ℃) to produce iron

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表 1 铁精粉的化学组成

Table 1. Chemical composition of iron concentrate powder

Sample w/%
TFe SiO₂ MgO CaO Al₂O₃

Iron powder 53.04 19.37 2.897 6.52 1.46

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表 2 各种铁氧化物拉曼频率对照表

Table 2. Raman frequency of different iron oxide^[26-27]

样品 Raman shift/cm^-1

α-Fe₂O₃ 227　246　293　411　497　612　1 320
Fe₃O₄ 302　513　534　663
γ-FeOOH 252　380　526　650　1 307

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参考文献(30)

[1]	KARALI N, PARK W Y, MCNEIL M. Modeling technological change and its impact on energy savings in the U.S. iron and steel sector[J]. Applied Energy, 2017, 202: 447-458. doi: 10.1016/j.apenergy.2017.05.173
[2]	WU X, ZHAO L, ZHANG Y, et. al Cost and potential of energy conservation and collaborative pollutant reduction in the iron and steel industry in China[J]. Applied Energy, 2016, 184: 171-183. doi: 10.1016/j.apenergy.2016.09.094
[3]	HASANBEIGI A, ARENS M, PRICE L. Alternative emerging ironmaking technologies for energy-efficiency and carbon dioxide emissions reduction: A technical review[J]. Renewable and Sustainable Energy Reviews, 2014, 33: 645-658. doi: 10.1016/j.rser.2014.02.031
[4]	LU W K, JiANG X, YANG J L. Smelting reduction and direct reduction for alternative ironmaking[C]// 5th International Conference on Science and Technology of Ironmaking. Beijing: Journal of and Iron Steel Research, 2009, 16: 79-86.
[5]	CONSIDINE T J, JABLONOWSKI C, CONSIDINE D. The environment and new technology adoption in the US steel industry[J]. University Park, 2001, 5(3): 47-59.
[6]	CHEN H, ZHENG Z, CHEN Z, et al. Reduction of hematite (Fe₂O₃) to metallic iron (Fe) by CO in a micro fluidized bed reaction analyzer: A multistep kinetics study[J]. Powder Technology, 2017, 316: 410-420.
[7]	OH J, NOH D. The reduction kinetics of hematite particles in H₂ and CO atmospheres[J]. Fuel, 2017, 196: 144-153. doi: 10.1016/j.fuel.2016.10.125
[8]	BOHN C D, CLEETON J P, MÜLLER C R, et al. The kinetics of the reduction of iron oxide by carbon monoxide mixed with carbon dioxide[J]. AIChE Journal, 2010, 56(4): 1016-1029.
[9]	CHEN F, MOHASSAB Y, JIANG T, et al. Hydrogen reduction kinetics of hematite concentrate particles relevant to a novel flash ironmaking process[J]. Metallurgical and Materials Transactions B, 2015, 46: 1133-1145. doi: 10.1007/s11663-015-0332-z
[10]	CHEN F, MOHASSAB Y, ZHANG S, et al. Kinetics of the Reduction of Hematite Concentrate Particles by Carbon Monoxide Relevant to a Novel Flash Ironmaking Process[J]. Metallurgical and Materials Transactions B, 2015, 46: 1716-1728. doi: 10.1007/s11663-015-0345-7
[11]	CHOI M E, SOHN H Y. Development of green suspension ironmaking technology based on hydrogen reduction of iron oxide concentrate: rate measurements[J]. Ironmaking & Steelmaking, 2010, 37: 81-88.
[12]	ZUO H, WANG C, DONG J, et al. Reduction kinetics of iron oxide pellets with H₂ and CO mixtures[J]. International Journal of Minerals, Metallurgy, and Materials, 2015, 22: 688-696. doi: 10.1007/s12613-015-1123-x
[13]	LIN Y H, GUO Z C, TANG H Q. Reduction behavior with co under micro-fluidized bed conditions[J]. Journal of Iron and Steel Research International, 2013, 20(2): 8-13. doi: 10.1016/S1006-706X(13)60049-7
[14]	WONG P L M, KIM M J, KIM H S, et al. Sticking behaviour in direct reduction of iron ore[J]. Ironmaking & Steelmaking, 2013, 26(1): 53-57.
[15]	赵志龙, 唐惠庆, 郭占成. CO还原Fe₂O₃过程中金属铁析出的微观行为[J]. 钢铁研究学报, 2012, 24(11): 23-28.
[16]	赵志龙, 唐惠庆, 郭占成. CO气氛下还原Fe₂O₃过程中铁晶须生长的原位观察[C]// 2010年全国冶金物理化学学术会议专辑(上册), 2010: 5.
[17]	朱凯荪, 王建军. 二步法熔融还原中流态化预还原过程的粘结机理及其预防的研究[J]. 华东冶金学院学报, 1989, 1(3): 47-54.
[18]	齐渊洪, 许海川. 还原流化床内铁的析出形态与铁矿粉的粘结行为[J]. 钢铁研究学报, 1996, 2(5): 7-11.
[19]	WAGNER D, DEVISME O, PATISSON F, et al. A laboratory study of the reduction of iron oxides by hydrogen[J]. Physics, 2008, 43(44): 3302-3303.
[20]	HAYASHI S, IGUCHI Y. Factors affecting the sticking of fine iron ores during fluidized bed reduction[J]. Transactions of the Iron & Steel Institute of Japan, 1992, 32(9): 962-971.
[21]	钟昇平, 郭磊, 丁智勇, 等. 铁矿粉气基直接还原过程中铁晶须生长观察[J]. 有色金属科学与工程, 2018, 9(01): 15-21.
[22]	金永丽, 韩福铁, 于海, 等. 磁场对含SiO₂和CaO的铁氧化物还原的影响[J]. 钢铁钒钛, 2018, 39(06): 103-109.
[23]	YIRU Y, LEI G, DONG Y L, et al. Numerical analysis of gasification characteristics in combined coal gasification and flash ironmaking process[J]. Applied Thermal Engineering, 2020, 171.
[24]	YIRU Y, LEI G, DO NG, et al. Numerical simulation of the gasification-reduction coupling process in the innovative multi-generation system[J]. Applied Thermal Engineering, 2020, 168(C).
[25]	ELZOHIERY M, SOHN H Y, MOHASSAB Y. Kinetics of hydrogen reduction of magnetite concentrate particles in solid state relevant to flash ironmaking[J]. Steel research international, 2017, 88: 1600133. doi: 10.1002/srin.201600133
[26]	胡涛, 路欣, 阎研, 等. 用纯铁氧化法生长的铁氧化物样品的拉曼光谱研究[J]. 光谱学与光谱分析, 2004, 09: 1072-1074. doi: 10.3321/j.issn:1000-0593.2004.09.013
[27]	THIBEAU R J, BROWN C W, HEIDERSBACH R H. Application Spectrosc[M]. 1978, 32: 532.
[28]	YI L, HUANG Z, JIANG T. Sticking of iron ore pellets during reduction with hydrogen and carbon monoxide mixtures: Behavior and mechanism[J]. Powder Technology, 2013, 235(2): 1001-1007.
[29]	HALIM K S A, BAHGAT M, EL-KELESH H A, et al. Metallic iron whisker formation and growth during iron oxide reduction: Basicity effect[J]. Ironmaking & Steelmaking, 2009, 36(8): 631-640.
[30]	YANG X B, XIAO H U, CHEN Z Y, et al. Structure evolution in the reduction process of FeO powder by hydrogen[J]. Chinese Journal of Engineering, 2015, 1(5): 356-364.