Concurrent leaching of copper and cobalt from a copper–cobalt ore using sulfuric and organic acids

•Higher temperatures and H₂O₂ concentrations improved Cu and Co leaching efficiencies.•Citric acid and oxalic acid increased Cu and Co leaching efficiencies respectively.•Oxalic acid leaching was superior to citric acid due to ionisation and dissociation differences.•H₂SO₄-H₂O₂ was best for Cu, while organic acids-H₂O₂ gave higher Co yields.•Cu leaching is diffusion-controlled below 35 °C and reaction-controlled above 35 °C. A study involving the leaching of Cu and Co from a CuCo ore in sulfuric acid (H2SO4), citric acid (CA) and oxalic acid (OA) using hydrogen peroxide (H2O2) as oxidant, was carried out. The ore was characterised by x-ray fluorescence (XRF), x-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDX). The results obtained indicate that increasing the time, temperature, and concentration of the leaching agent/oxidant enhanced the leaching efficiencies of Cu and Co, while a reduction in particle size (large surface area) favours the leaching of Cu and Co. The highest leaching efficiencies of 99.2 % and 94.0 % were obtained for Cu and Co, respectively, in a leaching system constituted by 1.0 M H2SO4 and 3.0 M H2O2 within 4 h at 65 °C. In contrast, the 0.8 M OA leaching system demonstrated a 97.1 % efficiency for Cu and 100.0 % efficiency for Co. The estimated activation energy in the temperature range of 25–65 °C is 40.7 kJmol−1 for Cu, while that of Co is 64.0 kJmol−1, which implies that the leaching is controlled by a surface chemical reaction. A comprehensive analysis demonstrated that the reaction mechanism for Cu leaching is diffusion-controlled at lower temperatures (