Microwave-Assisted Reduction of Electric Arc Furnace Dust with Biochar

An Examination of Transition of Heating Mechanism

Qing Ye, Zhiwei Peng, Guanghui Li, Joonho Lee, Yong Liu, Mudan Liu, Liancheng Wang, Mingjun Rao, Yuanbo Zhang, Tao Jiang

Research output: Contribution to journalArticle

Abstract

This present study aimed to investigate the reduction behavior of hazardous electric arc furnace (EAF) dust in the presence of biochar (reducing agent) based on self-reduction of their composites under microwave irradiation with an emphasis on the microwave heating mechanism. The experimental results showed that after microwave-assisted reduction the iron metallization degree of the product reached 94.7%, much higher than that (67.6%) by conventional heating. It was revealed that the "lens effect" promoted the directional migration of the gangue elements and the newly generated metallic iron component in the microwave field. Further analysis of electromagnetic characteristics of the composite system demonstrated that its self-reduction relied heavily on the microwave heating mechanism, which underwent multiple transitions during the reduction process. The dielectric polarization and magnetic loss dominated the initial stage of microwave heating (stage I, <873 K), promoting volumetric heating. In the following stage (stage II, 873-1073 K), the dielectric polarization intensified as the dielectric parameters kept increasing due to the strong reduction reactions of Fe3O4 and ZnFe2O4. In stage III (>1073 K), the conductive loss became more apparent because of the release of volatiles and increase of the newly generated metallic iron phase, producing enhanced electronic conduction that was expected to speed up the reduction process.

Original languageEnglish
Pages (from-to)9515-9524
Number of pages10
JournalACS Sustainable Chemistry and Engineering
Volume7
Issue number10
DOIs
Publication statusPublished - 2019 May 20

Fingerprint

Electric arcs
Dust
Furnaces
Microwaves
dust
heating
Heating
Microwave heating
Iron
iron
Magnetic leakage
Microwave irradiation
gangue
Reducing Agents
Reducing agents
Metallizing
biochar
furnace
microwave
Large scale systems

Keywords

  • Biochar
  • Electric arc furnace dust
  • Microwave heating mechanism
  • Permeability
  • Permittivity

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Renewable Energy, Sustainability and the Environment

Cite this

Microwave-Assisted Reduction of Electric Arc Furnace Dust with Biochar : An Examination of Transition of Heating Mechanism. / Ye, Qing; Peng, Zhiwei; Li, Guanghui; Lee, Joonho; Liu, Yong; Liu, Mudan; Wang, Liancheng; Rao, Mingjun; Zhang, Yuanbo; Jiang, Tao.

In: ACS Sustainable Chemistry and Engineering, Vol. 7, No. 10, 20.05.2019, p. 9515-9524.

Research output: Contribution to journalArticle

Ye, Qing ; Peng, Zhiwei ; Li, Guanghui ; Lee, Joonho ; Liu, Yong ; Liu, Mudan ; Wang, Liancheng ; Rao, Mingjun ; Zhang, Yuanbo ; Jiang, Tao. / Microwave-Assisted Reduction of Electric Arc Furnace Dust with Biochar : An Examination of Transition of Heating Mechanism. In: ACS Sustainable Chemistry and Engineering. 2019 ; Vol. 7, No. 10. pp. 9515-9524.
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