Iodide-assisted leaching of chalcopyrite in acidic ferric sulfate media

G. Granata, A. Miura, W. Liu, F. Pagnanelli, Chiharu Tokoro

Research output: Contribution to journalArticle

Abstract

Chalcopyrite leaching in acidic ferric sulfate media at ambient temperature exhibits slow kinetics due to the formation of passivation layers on chalcopyrite surfaces. In this study, we investigated the use of potassium iodide to assist chalcopyrite leaching and proposed mechanisms by which iodide enhanced the leaching efficiency. The effect of ferric concentration, temperature and iodide concentration on chalcopyrite leaching was studied by factorial experimental design and statistical analysis of data using the analysis of variance (ANOVA) method. The addition of 0.5 g/L of potassium iodide to the leaching media containing Fe(III) resulted in the production of I 2 and led to an increase of copper extraction by 47% at 50 °C. Controlled potential experiments highlighted an optimal potential window for leaching at 700–800 mV, thus suggesting that tri-iodide might play a significant role in leaching enhancement. Mineral liberation analysis (MLA) highlighted that elemental sulfur was the surface product generated from the oxidation of chalcopyrite. The rate parameters in the presence of KI were significantly higher, especially at lower temperature, and consistent with those observed for the H 2 SO 4 -I 2 leaching media. The addition of potassium iodide into the leaching media led to a decrease of activation energy from 81.4 to 33.8 kJ/mol.

Original languageEnglish
Pages (from-to)244-251
Number of pages8
JournalHydrometallurgy
Volume186
DOIs
Publication statusPublished - 2019 Jun 1

Fingerprint

Iodides
Leaching
Potassium iodide
Potassium Iodide
chalcopyrite
ferric sulfate
Sulfates
Analysis of variance (ANOVA)
Sulfur
Passivation
Design of experiments
Temperature
Minerals
Copper
Statistical methods
Activation energy
Oxidation
Kinetics

Keywords

  • Chalcopyrite
  • Copper leaching
  • Iodine
  • MLA
  • Shrinking-core
  • Sulfur

ASJC Scopus subject areas

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

Cite this

Iodide-assisted leaching of chalcopyrite in acidic ferric sulfate media. / Granata, G.; Miura, A.; Liu, W.; Pagnanelli, F.; Tokoro, Chiharu.

In: Hydrometallurgy, Vol. 186, 01.06.2019, p. 244-251.

Research output: Contribution to journalArticle

Granata, G. ; Miura, A. ; Liu, W. ; Pagnanelli, F. ; Tokoro, Chiharu. / Iodide-assisted leaching of chalcopyrite in acidic ferric sulfate media. In: Hydrometallurgy. 2019 ; Vol. 186. pp. 244-251.
@article{785d479d57214dcb8654a68373597026,
title = "Iodide-assisted leaching of chalcopyrite in acidic ferric sulfate media",
abstract = "Chalcopyrite leaching in acidic ferric sulfate media at ambient temperature exhibits slow kinetics due to the formation of passivation layers on chalcopyrite surfaces. In this study, we investigated the use of potassium iodide to assist chalcopyrite leaching and proposed mechanisms by which iodide enhanced the leaching efficiency. The effect of ferric concentration, temperature and iodide concentration on chalcopyrite leaching was studied by factorial experimental design and statistical analysis of data using the analysis of variance (ANOVA) method. The addition of 0.5 g/L of potassium iodide to the leaching media containing Fe(III) resulted in the production of I 2 and led to an increase of copper extraction by 47{\%} at 50 °C. Controlled potential experiments highlighted an optimal potential window for leaching at 700–800 mV, thus suggesting that tri-iodide might play a significant role in leaching enhancement. Mineral liberation analysis (MLA) highlighted that elemental sulfur was the surface product generated from the oxidation of chalcopyrite. The rate parameters in the presence of KI were significantly higher, especially at lower temperature, and consistent with those observed for the H 2 SO 4 -I 2 leaching media. The addition of potassium iodide into the leaching media led to a decrease of activation energy from 81.4 to 33.8 kJ/mol.",
keywords = "Chalcopyrite, Copper leaching, Iodine, MLA, Shrinking-core, Sulfur",
author = "G. Granata and A. Miura and W. Liu and F. Pagnanelli and Chiharu Tokoro",
year = "2019",
month = "6",
day = "1",
doi = "10.1016/j.hydromet.2019.04.019",
language = "English",
volume = "186",
pages = "244--251",
journal = "Hydrometallurgy",
issn = "0304-386X",
publisher = "Elsevier",

}

TY - JOUR

T1 - Iodide-assisted leaching of chalcopyrite in acidic ferric sulfate media

AU - Granata, G.

AU - Miura, A.

AU - Liu, W.

AU - Pagnanelli, F.

AU - Tokoro, Chiharu

PY - 2019/6/1

Y1 - 2019/6/1

N2 - Chalcopyrite leaching in acidic ferric sulfate media at ambient temperature exhibits slow kinetics due to the formation of passivation layers on chalcopyrite surfaces. In this study, we investigated the use of potassium iodide to assist chalcopyrite leaching and proposed mechanisms by which iodide enhanced the leaching efficiency. The effect of ferric concentration, temperature and iodide concentration on chalcopyrite leaching was studied by factorial experimental design and statistical analysis of data using the analysis of variance (ANOVA) method. The addition of 0.5 g/L of potassium iodide to the leaching media containing Fe(III) resulted in the production of I 2 and led to an increase of copper extraction by 47% at 50 °C. Controlled potential experiments highlighted an optimal potential window for leaching at 700–800 mV, thus suggesting that tri-iodide might play a significant role in leaching enhancement. Mineral liberation analysis (MLA) highlighted that elemental sulfur was the surface product generated from the oxidation of chalcopyrite. The rate parameters in the presence of KI were significantly higher, especially at lower temperature, and consistent with those observed for the H 2 SO 4 -I 2 leaching media. The addition of potassium iodide into the leaching media led to a decrease of activation energy from 81.4 to 33.8 kJ/mol.

AB - Chalcopyrite leaching in acidic ferric sulfate media at ambient temperature exhibits slow kinetics due to the formation of passivation layers on chalcopyrite surfaces. In this study, we investigated the use of potassium iodide to assist chalcopyrite leaching and proposed mechanisms by which iodide enhanced the leaching efficiency. The effect of ferric concentration, temperature and iodide concentration on chalcopyrite leaching was studied by factorial experimental design and statistical analysis of data using the analysis of variance (ANOVA) method. The addition of 0.5 g/L of potassium iodide to the leaching media containing Fe(III) resulted in the production of I 2 and led to an increase of copper extraction by 47% at 50 °C. Controlled potential experiments highlighted an optimal potential window for leaching at 700–800 mV, thus suggesting that tri-iodide might play a significant role in leaching enhancement. Mineral liberation analysis (MLA) highlighted that elemental sulfur was the surface product generated from the oxidation of chalcopyrite. The rate parameters in the presence of KI were significantly higher, especially at lower temperature, and consistent with those observed for the H 2 SO 4 -I 2 leaching media. The addition of potassium iodide into the leaching media led to a decrease of activation energy from 81.4 to 33.8 kJ/mol.

KW - Chalcopyrite

KW - Copper leaching

KW - Iodine

KW - MLA

KW - Shrinking-core

KW - Sulfur

UR - http://www.scopus.com/inward/record.url?scp=85064616647&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85064616647&partnerID=8YFLogxK

U2 - 10.1016/j.hydromet.2019.04.019

DO - 10.1016/j.hydromet.2019.04.019

M3 - Article

VL - 186

SP - 244

EP - 251

JO - Hydrometallurgy

JF - Hydrometallurgy

SN - 0304-386X

ER -