A kinetic model for halogenation of the zinc content in franklinite

Mohammednoor Altarawneh, Oday H. Ahmed, Mohammad Al-Harahsheh, Zhong Tao Jiang, Bogdan Z. Dlugogorski

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

Electric arc furnace dust (EAFD) signifies a major source of recyclable zinc. Most of the zinc load in EAFD exists as zincite (ZnO) and franklinite (ZnFe2O4). The heterogenous mixture of EAFD renders it technologically challenging to extract the valuable zinc content in EAFD via commonly utilized hydrometallurgical and pyrometallurgical operations. Co-pyrolysis of EAFD with halogen-containing polymers (most notably polyvinyl chloride, PVC, and brominated flame retardants, BFRs) is currently deployed as a potent approach in the selective extraction of zinc from EAFD. A robust optimization of this process necessitates acquiring accurate and representative kinetic parameters of involved chemical reactions. Herein, we construct a microkinetic model that accounts the surface halogenation of zinc ions in franklinite into zinc halides (ZnCl2/ZnBr2). Governing reaction and activation energies for the dissociative adsorption of hydrogen halides and alkyl halides with a franklinite surface were computed with the DFT + U formalism. Products profiles from the constructed kinetic model are discussed in the context of literature available experimental measurements pertinent to transformation of zinc into zinc halides. The predicted temperature window for the synthesis of surface ZnCl2/ZnBr2 moieties coincides with analogous results inferred from pyrolysis experiments. Uptake of HCl and HBr by franklinite commences at 600 K and 500 K, respectively. The model satisfactorily illustrates chemical phenomena that dictate the mass loss curves in EAFD-PVC/BFRs formulations, most notably dehalogenation of halogenated alkanes, evaporation of zinc halides evaporation, and water evolution.

Original languageEnglish
Article number150105
JournalApplied Surface Science
Volume562
DOIs
Publication statusPublished - Oct 1 2021

Keywords

  • Electric arc furnace dust
  • Halogenation
  • Kinetic model
  • Zinc

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

Fingerprint

Dive into the research topics of 'A kinetic model for halogenation of the zinc content in franklinite'. Together they form a unique fingerprint.

Cite this