The anodic behaviour of chalcopyrite in chloride solutions

Voltammetry

Michael Nicol, Hajime Miki, Suchun Zhang

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

This paper summarizes the results of a voltammetric study of the anodic characteristics of chalcopyrite in the potential region relevant to heap leaching in concentrated chloride solutions. Distinct peaks in the potential region of 0.7 to 0.85 V have been observed in the voltammograms, the magnitude of which depend on the chloride concentration and, particularly, the pH in the range 1 to 3. Three peaks are observed at low chloride concentrations that merge into one peak at higher concentrations. The anodic reactivity increases with increasing pH but shows a complex dependence on the chloride concentration while in the presence of added copper(II) ions, the mixed potential shifts to more positive potentials and only one peak is observed. Hysteresis between the forward and backward-going sweeps has confirmed the transient nature of the processes except at potentials below about 0.75 V in which region the system approaches steady-state behaviour. The voltammetric characteristics of chalcopyrite in this system appear to be very similar to those of covellite. Measurements of the initial rates of dissolution (in the range 1–5 × 10− 10 mol cm− 2 s− 1 depending on the conditions) have been made that confirm the voltammetric trends and compare well with previously published rates. Linear free energy relationships have been used to estimate the thermodynamic properties (Gibbs free energy − 100.7 kJ/mol) of the simplest polysulfide, namely CuS2 and possible mechanisms for the various steps in the anodic dissolution and passivation of chalcopyrite have been suggested that are consistent with the thermodynamic predictions.

Original languageEnglish
Pages (from-to)198-205
Number of pages8
JournalHydrometallurgy
Volume171
DOIs
Publication statusPublished - Aug 1 2017

Fingerprint

Voltammetry
Chlorides
Dissolution
Polysulfides
Gibbs free energy
Passivation
Leaching
Free energy
Hysteresis
Thermodynamic properties
Thermodynamics
Copper
Ions
chalcopyrite

All Science Journal Classification (ASJC) codes

  • Industrial and Manufacturing Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

The anodic behaviour of chalcopyrite in chloride solutions : Voltammetry. / Nicol, Michael; Miki, Hajime; Zhang, Suchun.

In: Hydrometallurgy, Vol. 171, 01.08.2017, p. 198-205.

Research output: Contribution to journalArticle

Nicol, Michael ; Miki, Hajime ; Zhang, Suchun. / The anodic behaviour of chalcopyrite in chloride solutions : Voltammetry. In: Hydrometallurgy. 2017 ; Vol. 171. pp. 198-205.
@article{b40438f3bc16499080ee2499bca9cdc2,
title = "The anodic behaviour of chalcopyrite in chloride solutions: Voltammetry",
abstract = "This paper summarizes the results of a voltammetric study of the anodic characteristics of chalcopyrite in the potential region relevant to heap leaching in concentrated chloride solutions. Distinct peaks in the potential region of 0.7 to 0.85 V have been observed in the voltammograms, the magnitude of which depend on the chloride concentration and, particularly, the pH in the range 1 to 3. Three peaks are observed at low chloride concentrations that merge into one peak at higher concentrations. The anodic reactivity increases with increasing pH but shows a complex dependence on the chloride concentration while in the presence of added copper(II) ions, the mixed potential shifts to more positive potentials and only one peak is observed. Hysteresis between the forward and backward-going sweeps has confirmed the transient nature of the processes except at potentials below about 0.75 V in which region the system approaches steady-state behaviour. The voltammetric characteristics of chalcopyrite in this system appear to be very similar to those of covellite. Measurements of the initial rates of dissolution (in the range 1–5 × 10− 10 mol cm− 2 s− 1 depending on the conditions) have been made that confirm the voltammetric trends and compare well with previously published rates. Linear free energy relationships have been used to estimate the thermodynamic properties (Gibbs free energy − 100.7 kJ/mol) of the simplest polysulfide, namely CuS2 and possible mechanisms for the various steps in the anodic dissolution and passivation of chalcopyrite have been suggested that are consistent with the thermodynamic predictions.",
author = "Michael Nicol and Hajime Miki and Suchun Zhang",
year = "2017",
month = "8",
day = "1",
doi = "10.1016/j.hydromet.2017.05.016",
language = "English",
volume = "171",
pages = "198--205",
journal = "Hydrometallurgy",
issn = "0304-386X",
publisher = "Elsevier",

}

TY - JOUR

T1 - The anodic behaviour of chalcopyrite in chloride solutions

T2 - Voltammetry

AU - Nicol, Michael

AU - Miki, Hajime

AU - Zhang, Suchun

PY - 2017/8/1

Y1 - 2017/8/1

N2 - This paper summarizes the results of a voltammetric study of the anodic characteristics of chalcopyrite in the potential region relevant to heap leaching in concentrated chloride solutions. Distinct peaks in the potential region of 0.7 to 0.85 V have been observed in the voltammograms, the magnitude of which depend on the chloride concentration and, particularly, the pH in the range 1 to 3. Three peaks are observed at low chloride concentrations that merge into one peak at higher concentrations. The anodic reactivity increases with increasing pH but shows a complex dependence on the chloride concentration while in the presence of added copper(II) ions, the mixed potential shifts to more positive potentials and only one peak is observed. Hysteresis between the forward and backward-going sweeps has confirmed the transient nature of the processes except at potentials below about 0.75 V in which region the system approaches steady-state behaviour. The voltammetric characteristics of chalcopyrite in this system appear to be very similar to those of covellite. Measurements of the initial rates of dissolution (in the range 1–5 × 10− 10 mol cm− 2 s− 1 depending on the conditions) have been made that confirm the voltammetric trends and compare well with previously published rates. Linear free energy relationships have been used to estimate the thermodynamic properties (Gibbs free energy − 100.7 kJ/mol) of the simplest polysulfide, namely CuS2 and possible mechanisms for the various steps in the anodic dissolution and passivation of chalcopyrite have been suggested that are consistent with the thermodynamic predictions.

AB - This paper summarizes the results of a voltammetric study of the anodic characteristics of chalcopyrite in the potential region relevant to heap leaching in concentrated chloride solutions. Distinct peaks in the potential region of 0.7 to 0.85 V have been observed in the voltammograms, the magnitude of which depend on the chloride concentration and, particularly, the pH in the range 1 to 3. Three peaks are observed at low chloride concentrations that merge into one peak at higher concentrations. The anodic reactivity increases with increasing pH but shows a complex dependence on the chloride concentration while in the presence of added copper(II) ions, the mixed potential shifts to more positive potentials and only one peak is observed. Hysteresis between the forward and backward-going sweeps has confirmed the transient nature of the processes except at potentials below about 0.75 V in which region the system approaches steady-state behaviour. The voltammetric characteristics of chalcopyrite in this system appear to be very similar to those of covellite. Measurements of the initial rates of dissolution (in the range 1–5 × 10− 10 mol cm− 2 s− 1 depending on the conditions) have been made that confirm the voltammetric trends and compare well with previously published rates. Linear free energy relationships have been used to estimate the thermodynamic properties (Gibbs free energy − 100.7 kJ/mol) of the simplest polysulfide, namely CuS2 and possible mechanisms for the various steps in the anodic dissolution and passivation of chalcopyrite have been suggested that are consistent with the thermodynamic predictions.

UR - http://www.scopus.com/inward/record.url?scp=85019573515&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85019573515&partnerID=8YFLogxK

U2 - 10.1016/j.hydromet.2017.05.016

DO - 10.1016/j.hydromet.2017.05.016

M3 - Article

VL - 171

SP - 198

EP - 205

JO - Hydrometallurgy

JF - Hydrometallurgy

SN - 0304-386X

ER -