Selective leaching of zinc from zinc fer

The hydrometallurgical extraction of zinc from electric arc furnace (EAF) dust and steel-making sludge was investigated to address the hazardous nature of these materials due to heavy metals present. This study aimed to optimize the recovery of zinc using sulphuric acid under elevated pressure and microwave heating conditions. Experimental methods involved treating EAF dust and steel-making sludge with a 0.3 M sulphuric acid solution at 260 °C. Results indicated that over 92% of zinc could be leached from the waste materials, while iron (Fe(II)) remained soluble and Fe(III) precipitated as hematite. The addition of hydrogen peroxide significantly enhanced zinc extraction, reaching nearly 99%. Furthermore, the hydrolytic precipitation of ferric sulphate was examined at 200 °C for low iron concentrations, revealing a first-order reaction with respect to Fe(III) with an apparent rate constant of 0.001 min−1. These findings suggest a viable hydrometallurgical approach for zinc recovery from steel-making wastes, contributing to waste valorization and resource recycling in metallurgical processes.