Loading…

Kinetic study of chalcopyrite dissolution with iron(III) chloride in methanesulfonic acid

•MSA/ferric leaching of chalcopyrite was surface chemical-reaction controlled.•MSA may prevent iron hydrolysis.•Similar leaching results to hydrochloric acid but with environmental advantages.•Leach kinetics dependent on temperature and particle size.•Constant activation energy (101 kJ mol−1) found...

Full description

Saved in:
Bibliographic Details
Published in:Minerals engineering 2018-08, Vol.125, p.66-74
Main Authors: Hidalgo, Tania, Kuhar, Laura, Beinlich, Andreas, Putnis, Andrew
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•MSA/ferric leaching of chalcopyrite was surface chemical-reaction controlled.•MSA may prevent iron hydrolysis.•Similar leaching results to hydrochloric acid but with environmental advantages.•Leach kinetics dependent on temperature and particle size.•Constant activation energy (101 kJ mol−1) found for chalcopyrite dissolution. The suitability of methanesulfonic acid as a copper lixiviant with ferric chloride as an oxidant was studied by analysing the leaching kinetics and by characterising solid residues from leach tests on a chalcopyrite-rich ore sample. The effects of temperature, initial acidity, ferric-ion concentration and particle size were determined. The leach kinetics were dependent on the temperature and particle size, whereas the acid and ferric concentrations had a minimal impact on the leaching rate within the ranges studied. Although a sulfur layer formed on the solid residue, the reaction mechanism could be modeled with the shrinking-core model with surface chemical-reaction control, which implies that lixiviant flow through the sulfur layer did not control the reaction rate. The apparent activation energy was 101 kJ mol−1 as calculated by the Arrhenius and 'time-to-a-given-fraction' methods. The activation parameters of the reaction were an enthalpy (ΔH++) of 99.4 kJ mol−1, and an entropy (ΔS++) of −197 J mol−1 K−1 as calculated by using transition state theory and the Eyring equation.
ISSN:0892-6875
1872-9444
DOI:10.1016/j.mineng.2018.05.025