Leaching Kinetics of Lead from Galena Using Hydrogen Peroxide and Trichloroacetic Acid

Abstract

The leaching kinetics of lead (Pb) from galena using hydrogen peroxide (H2O2) in trichloroacetic acid (TCA) solution will be explored in this study. The influence of temperature, stirring speed, concentrations of H2O2 and TCA as well as particle size, will be analyzed. The dissolution kinetics followed a shrinking core model, with the diffusion of some species as the rate-determining step. The value of activation energy obtained in this study was 39.89 kJ/mol, which meant that the leaching of Pb was controlled by a surface chemical reaction. The reaction order for H2O2 was 0.55 and the order of reaction for TCA was 0.44. Overall, the leaching of Pb from galena relied mainly on the concentrations of TCA and H2O2, temperature, particle size, and stirring speed. The combination of TCA and H2O2 leached substantial amounts of Pb from galena.