Electrochemical Kinetics Study of Ultrasound-Assisted Chalcopyrite Oxidation
Lin Li, Aaron A. King, Krystal Davis, Ben Yu
Abstract
Abstract Ultrasound-assisted chalcopyrite leaching has been reported previously, showing a noticeable improvement in leaching kinetics. However, the effect of ultrasound on the chalcopyrite oxidation kinetics from an electrochemical perspective has not been addressed. This study examines the ultrasonic enhancement of chalcopyrite oxidation kinetics in sulfuric acid solution from both conventional leaching and electrochemistry aspects. Electrochemical techniques, including linear sweep voltammetry (LSV) and chronoamperometry (CA), were used to illustrate the kinetics of chalcopyrite ultrasound-assisted leaching. Tafel analysis by LSV showed that 20% amplitude ultrasound power had increased the chalcopyrite electrochemical dissolution rate by about 20% in both Fe 3+ -free and 10 mM Fe 3+ -containing 0.5 M sulfuric acid solution. The CA tests indicated a drastic increase in the Fe 3+ reduction reaction when ultrasound was applied (20% amplitude). At 0.5 V, the Fe 3+ to Fe 2+ reduction current density at 30 min drastically increased from − 65.54 without ultrasound to − 1165.84 µA cm −2 with ultrasound. Graphical Abstract