Electrochemical Insights into the Direct Dissolution of Impure Sphalerites and Their Partial Oxidation in an Acidic Environment

Author

Gholamreza Khodadadmahmoudi
Saeid Karimi
Hadi Abdollahi
Milad Karimi
Ali Rezaei
Lana Alagha, Missouri University of Science and TechnologyFollow

Abstract

This study examined the electro dissolution mechanism of five impure sphalerite samples, which differ significantly in purity levels, along with their partially oxidized counterparts in a 0.5 M H₂SO₄. Partially oxidized samples were prepared through an incomplete leaching of sphalerite using H₂SO₄ with Fe₂(SO₄)₃.H₂O as an oxidizing agent. The original sphalerite samples and the partially oxidized samples were referred to as SP and POS samples, respectively. Analyses using XRD, SEM, Raman spectroscopy, and electrochemical techniques suggested presence of elemental sulfur and a metal-deficient layer on the surface of the POS samples. Cyclic voltammetry revealed that the sample with the highest iron content exhibited the highest electrochemical response, while the sphalerite with the highest lead concentration had the lowest activity. Electrochemical impedance spectroscopy (EIS) studies showed that impedance values were higher in the POS samples compared to the PS samples, indicating a correlation within the passivation phenomenon. In conclusion, these findings suggested that the sphalerite dissolution process is primarily controlled by charge transfer and kinetic polarization. This understanding can lead to the development of more selective and sustainable extraction methods and improving the overall economic viability of zinc hydrometallurgical operations.

Recommended Citation

G. Khodadadmahmoudi et al., "Electrochemical Insights into the Direct Dissolution of Impure Sphalerites and Their Partial Oxidation in an Acidic Environment," Scientific reports, vol. 15, no. 1, p. 3005, Nature Research, Jan 2025.

The definitive version is available at https://doi.org/10.1038/s41598-025-87270-7

Department(s)

Mining Engineering

Publication Status

Open Access

Keywords and Phrases

Cyclic voltammetry; Electrochemical impedance spectroscopy; Electrometallurgy; Partial leaching; Sphalerite

International Standard Serial Number (ISSN)

2045-2322

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2025 The Authors, All rights reserved.

Creative Commons Licensing

This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

23 Jan 2025

PubMed ID

39849067