Sulfuric Acid Leaching оf Zinc Ferrite Residue

Biserka Lucheva, Peter Iliev, Nadezhda Kazakova, Vladislava Stefanova and Hristo Ivanov

DOI: https://doi.org/10.64486/m.65.1.6
Online publication date: September 11, 2025

Abstract: Zinc ferrite residue, a by-product from the hydrometallurgical processing of zinc calcine, contains significant amounts of zinc, iron, lead, copper, and silver, often locked in complex oxide and spinel phases. This study aims to characterize zinc ferrite residue using ICP-OES analysis, XRD, and SEM/EDS, and to evaluate its behavior during sulfuric acid leaching under controlled laboratory conditions. Thermodynamic modeling with HSC Chemistry software was used to construct Eh–pH diagrams and predict phase stability across different temperatures and redox conditions. The experimental results confirmed efficient leaching of zinc, copper and iron, while lead and silver were largely retained in the insoluble resi-due. These findings highlight the potential for selective zinc extraction and con-centration of lead and silver in the solid phase, offering a promising route for sus-tainable ZFR processing.

Keywords: zinc ferrite residue, sulfuric acid leaching, thermodynamic modeling

This article is published online first and will appear in Metalurgija, Vol. 65, Issue 1 (2026).