自然科学版 英文版
自然科学版 英文版
自然科学版 英文版
自然科学版 英文版
英文版编委
自然科学版 英文版
英文版首届青年编委

您目前所在的位置:首页 - 期刊简介 - 详细页面

中南大学学报(自然科学版)

Journal of Central South University

第49卷    第11期    总第291期    2018年11月

[PDF全文下载]    [Flash在线阅读]

    

文章编号:1672-7207(2018)11-2643-06
赤铁矿流化床还原过程中磁铁矿的形成与生长规律
余建文,韩跃新,李艳军,高鹏

(东北大学 资源与土木工程学院,辽宁 沈阳,110819)

摘 要: 以20% CO-80% CO2(质量分数)为还原流化气体,借助光学显微镜、扫描电镜研究赤铁矿流化床还原过程中磁铁矿的形成与生长规律。研究结果表明:新生磁铁矿晶核呈针状,长度不一且优先在赤铁矿颗粒的边缘处形成;还原温度和焙烧时间对产物磁铁矿层的厚度影响显著,随着还原温度升高和焙烧时间延长,产物磁铁矿层厚度增加;磁铁矿的生长过程可分为2个不同的阶段即诱导期和生长期,且产物磁铁矿层厚度增长与还原时间的关系符合抛物线定律;在诱导期,生长过程的指前因子k0=1.95×105 μm2/min,活化能ΔEa=60.86 kJ/mol;在生长期,生长过程的指前因子k0=9.77×104 μm2/min,活化能ΔEa=35.71 kJ/mol。

 

关键词: 赤铁矿;悬浮磁化焙烧;磁铁矿;生长动力学

Formation and growth mechanism of magnetite during the fluidized reduction of hematite
YU Jianwen, HAN Yuexin, LI Yanjun, GAO Peng

School of Resources & Civil Engineering, Northeastern University, Shenyang 110819, China

Abstract:A gas mixture of 20% CO-80% CO2 was used as reducing and fluidizing agent, and the formation and growth mechanism of magnetite phase during the fluidized reduction of hematite was investigated by optical microscopy and scanning electron microscopy(SEM). The results show that the fresh magnetite nucleus are needle-like with different lengths, and are preferentially formed at the edges of original hematite particle. The reduction temperature and roasting time have significant effect on thickness of the magnetite product layer. With the increase of reduction temperature and roasting time, the thickness of magnetite layer increases. The growth process of magnetite phase can be divided into two different stages which includes induction period and growth period, and the growth mechanism of magnetite phase coincides with the parabolic law. In the induction and growth periods, the pre-exponential factor k0 is 1.95×105μm2/min and 9.77×104 μm2/min, the activation energy ΔEa is 60.86 kJ/mol and 35.71 kJ/mol, respectively.

 

Key words: hematite; fluidized magnetization roasting; magnetite; growth kinetics

中南大学学报(自然科学版)
  ISSN 1672-7207
CN 43-1426/N
ZDXZAC
中南大学学报(英文版)
  ISSN 2095-2899
CN 43-1516/TB
JCSTFT
版权所有:《中南大学学报(自然科学版、英文版)》编辑部
地 址:湖南省长沙市中南大学 邮编: 410083
电 话: 0731-88879765(中) 88836963(英) 传真: 0731-88877727
电子邮箱:zngdxb@csu.edu.cn 湘ICP备09001153号