Thermodynamics Study for Selective Leaching of Copper and Zinc from Complex Secondary Raw Materials Using Oxidative Sulfuric Acid Leaching

Abstract

This study focuses on evaluating the optimal process conditions for selectively leaching copper and zinc from complex secondary raw materials using the oxidative sulfuric acid leaching process. The research includes both physical and chemical characterization of the materials and a comprehensive thermodynamic analysis to assess the thermodynamic properties and behaviors of the system under investigation. The physical characterization involves determining parameters such as bulk density, moisture content, and granulometric composition of the samples. Elemental composition analysis is performed using X-ray fluorescence spectrometry (XRF) and energy dispersion spectroscopy (EDX), while the phase composition is determined through X-ray diffraction (XRD) analysis. Additionally, the materials' morphology is examined using scanning electron microscopy (SEM). Fraction diagrams are created using Hydra/Medusa software to assess the phase distributions of zinc and copper during the leaching process. The stability of the metals and potential chemical reactions within a defined temperature range is analyzed using Eh-pH diagrams with the HSC 9 Chemistry Software. Based on the thermodynamic analysis conducted, it is determined that effective leaching of copper and zinc from the complex secondary raw materials is achievable. Furthermore, the results indicate that the leaching process is relatively insensitive to temperature variations. The optimization of the leaching process should primarily focus on achieving optimized consumption of the oxidizing agent.