Investigation of SiC formation on the graphite surface by CO-H2-SiO gas

Mintae Kim, Sangho Jeon, Junwoo Park, Jiwoo Park, Moo Eob Choi, Joonho Lee

Research output: Contribution to journalArticlepeer-review

Abstract

FINEX process, which utilizes hydrogen (H2) as a part of reductants, has emerged as an environmentally sustainable ironmaking process to meet the upcoming carbon-neutral era. In the H2-enriched atmosphere, local slag holdup in the carbonaceous particle bed may increase due to the increased melting temperature of slags by the rapid reduction of iron oxide and the resulting lower wettability of the carbonaceous materials by liquid slag. In-situ SiC formation on the carbon surface gains much attention as a method to reduce the slag holdup. In this study, as a fundamental study, we investigated the SiC formation on the surface of a graphite substrate under a CO-H2-SiO gas environment at 1873 K. It was found that as the partial pressure of H2 increased, the penetration depth of a SiC layer formed on the graphite surface increased, and the surface roughness became enhanced. A reaction rate analysis revealed that the H2-CO gas mixture accelerated the SiC formation on the graphite surface compared to the N2-CO gas mixture. This effect was attributed to the high bimolecular diffusivity of H2-CO. Our results demonstrate that under a CO-H2-SiO gas environment, the fast diffusion of H2 gas through micropores in the graphite significantly enhances the formation of SiC on the graphite surface. The results obtained in this study show that the acceleration of SiC formation under an H2-enriched atmosphere would improve the wettability of molten slag and reduce the slag holdup in the FINEX process.

Original languageEnglish
Pages (from-to)5373-5382
Number of pages10
JournalJournal of Materials Research and Technology
Volume26
DOIs
Publication statusPublished - 2023 Sept 1

Bibliographical note

Funding Information:
This work was supported by the Industrial Strategic Technology Development Program ( 20212010100040 , Development of hybrid ironmaking processes for lower CO2 emissions), funded by the Ministry of Trade, Industry & Energy in the Republic of Korea. MK and JP were supported by the Competency Development Program for Industry Specialists of Korea Institute for Advancement of Technology (grant no. P0002019 ) in the Republic of Korea. Jiwoo Park was supported by Korea Institute for Advancement of Technology grant funded by the Korea Government (MOTIE) (P0023676, HRD Program for Industrial Innovation). JL was supported by the Korea University Grant.

Publisher Copyright:
© 2023 The Authors

Keywords

  • CO emission
  • FINEX
  • Graphite
  • Hydrogen
  • Ironmaking
  • SiC formation

ASJC Scopus subject areas

  • Ceramics and Composites
  • Biomaterials
  • Surfaces, Coatings and Films
  • Metals and Alloys

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