Electro-remediation of tailings from a multi-metal sulphide mine: comparing removal efficiencies of Pb, Zn, Cu and Cd

Zhaoyu Zhang, Lisbeth M. Ottosen, Tairan Wu*, Pernille E. Jensen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Sulphidic mine tailings characterised by high concentrations of heavy metals (Pb 3532 ± 97 mg/kg, Zn 8450 ± 154 mg/kg, Cu 239 ± 18 mg/kg and Cd 14.1 ± 0.3 mg/kg) and abundant carbonate (17%) were subjected to eight lab-scale electrodialytic remediation (EDR) experiments to investigate the influence of current density, treatment time and particle size on removal efficiency. Pb and Cu removal improved when increasing current density, while Zn and Cd removal did not. In contrast Zn and Cd removal improved by grinding the tailings, while Pb and Cu removal did not. At the highest current density (1.2 mA/cm2), 94%, 75%, 71% and 67% removal of Pb, Zn, Cu and Cd could be achieved, respectively, on grinded tailings in 28 days. Sequential chemical extraction made before and after EDR revealed larger oxidisable fractions of Zn, Cu and Cd, representing large fractions of sulphides, which was likely to be the main barrier to be removed as efficiently as Pb. This was in accordance with acid/base extraction tests in which Pb showed high solubility at both high and low pH (up to 65% and 86% of extraction, respectively), while considerable extraction of Zn (55%) happened only at low pH; and very limited extraction (<20%) of Cu and Cd occurred at any pH.

Original languageEnglish
JournalChemistry and Ecology
Volume35
Issue number1
Pages (from-to)54-68
ISSN0275-7540
DOIs
Publication statusPublished - 2019

Keywords

  • Electrodialytic remediation
  • Heavy metals
  • Mine tailings
  • Sequential extraction

Cite this

@article{aabd697e094b45f293f45c33af6e0fdd,
title = "Electro-remediation of tailings from a multi-metal sulphide mine: comparing removal efficiencies of Pb, Zn, Cu and Cd",
abstract = "Sulphidic mine tailings characterised by high concentrations of heavy metals (Pb 3532 ± 97 mg/kg, Zn 8450 ± 154 mg/kg, Cu 239 ± 18 mg/kg and Cd 14.1 ± 0.3 mg/kg) and abundant carbonate (17{\%}) were subjected to eight lab-scale electrodialytic remediation (EDR) experiments to investigate the influence of current density, treatment time and particle size on removal efficiency. Pb and Cu removal improved when increasing current density, while Zn and Cd removal did not. In contrast Zn and Cd removal improved by grinding the tailings, while Pb and Cu removal did not. At the highest current density (1.2 mA/cm2), 94{\%}, 75{\%}, 71{\%} and 67{\%} removal of Pb, Zn, Cu and Cd could be achieved, respectively, on grinded tailings in 28 days. Sequential chemical extraction made before and after EDR revealed larger oxidisable fractions of Zn, Cu and Cd, representing large fractions of sulphides, which was likely to be the main barrier to be removed as efficiently as Pb. This was in accordance with acid/base extraction tests in which Pb showed high solubility at both high and low pH (up to 65{\%} and 86{\%} of extraction, respectively), while considerable extraction of Zn (55{\%}) happened only at low pH; and very limited extraction (<20{\%}) of Cu and Cd occurred at any pH.",
keywords = "Electrodialytic remediation, Heavy metals, Mine tailings, Sequential extraction",
author = "Zhaoyu Zhang and Ottosen, {Lisbeth M.} and Tairan Wu and Jensen, {Pernille E.}",
year = "2019",
doi = "10.1080/02757540.2018.1529173",
language = "English",
volume = "35",
pages = "54--68",
journal = "Chemistry and Ecology",
issn = "0275-7540",
publisher = "CRC Press/Balkema",
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}

Electro-remediation of tailings from a multi-metal sulphide mine: comparing removal efficiencies of Pb, Zn, Cu and Cd. / Zhang, Zhaoyu; Ottosen, Lisbeth M.; Wu, Tairan; Jensen, Pernille E.

In: Chemistry and Ecology, Vol. 35, No. 1, 2019, p. 54-68.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Electro-remediation of tailings from a multi-metal sulphide mine: comparing removal efficiencies of Pb, Zn, Cu and Cd

AU - Zhang, Zhaoyu

AU - Ottosen, Lisbeth M.

AU - Wu, Tairan

AU - Jensen, Pernille E.

PY - 2019

Y1 - 2019

N2 - Sulphidic mine tailings characterised by high concentrations of heavy metals (Pb 3532 ± 97 mg/kg, Zn 8450 ± 154 mg/kg, Cu 239 ± 18 mg/kg and Cd 14.1 ± 0.3 mg/kg) and abundant carbonate (17%) were subjected to eight lab-scale electrodialytic remediation (EDR) experiments to investigate the influence of current density, treatment time and particle size on removal efficiency. Pb and Cu removal improved when increasing current density, while Zn and Cd removal did not. In contrast Zn and Cd removal improved by grinding the tailings, while Pb and Cu removal did not. At the highest current density (1.2 mA/cm2), 94%, 75%, 71% and 67% removal of Pb, Zn, Cu and Cd could be achieved, respectively, on grinded tailings in 28 days. Sequential chemical extraction made before and after EDR revealed larger oxidisable fractions of Zn, Cu and Cd, representing large fractions of sulphides, which was likely to be the main barrier to be removed as efficiently as Pb. This was in accordance with acid/base extraction tests in which Pb showed high solubility at both high and low pH (up to 65% and 86% of extraction, respectively), while considerable extraction of Zn (55%) happened only at low pH; and very limited extraction (<20%) of Cu and Cd occurred at any pH.

AB - Sulphidic mine tailings characterised by high concentrations of heavy metals (Pb 3532 ± 97 mg/kg, Zn 8450 ± 154 mg/kg, Cu 239 ± 18 mg/kg and Cd 14.1 ± 0.3 mg/kg) and abundant carbonate (17%) were subjected to eight lab-scale electrodialytic remediation (EDR) experiments to investigate the influence of current density, treatment time and particle size on removal efficiency. Pb and Cu removal improved when increasing current density, while Zn and Cd removal did not. In contrast Zn and Cd removal improved by grinding the tailings, while Pb and Cu removal did not. At the highest current density (1.2 mA/cm2), 94%, 75%, 71% and 67% removal of Pb, Zn, Cu and Cd could be achieved, respectively, on grinded tailings in 28 days. Sequential chemical extraction made before and after EDR revealed larger oxidisable fractions of Zn, Cu and Cd, representing large fractions of sulphides, which was likely to be the main barrier to be removed as efficiently as Pb. This was in accordance with acid/base extraction tests in which Pb showed high solubility at both high and low pH (up to 65% and 86% of extraction, respectively), while considerable extraction of Zn (55%) happened only at low pH; and very limited extraction (<20%) of Cu and Cd occurred at any pH.

KW - Electrodialytic remediation

KW - Heavy metals

KW - Mine tailings

KW - Sequential extraction

U2 - 10.1080/02757540.2018.1529173

DO - 10.1080/02757540.2018.1529173

M3 - Journal article

AN - SCOPUS:85057321482

VL - 35

SP - 54

EP - 68

JO - Chemistry and Ecology

JF - Chemistry and Ecology

SN - 0275-7540

IS - 1

ER -