Oxidative acid leaching behavior of Fe–Ni–Co alloy powder derived from a laterite ore

The demand for Ni and Co has surged due to the rapid expansion of the electric vehicle industry. Thus, developing efficient and eco-friendly metallurgical routes for extracting these metals has become imperative. This study introduces a sustainable and effective method for extracting Ni and Co from Ni–Co–Fe alloy powder obtained from limonitic laterite ores through selective reduction and magnetic separation. The leaching efficiency for Ni, Co, and Fe was 89.4%, 94.8%, and 96.5%, respectively, under the following conditions for leaching: 3 mol/L H₂SO₄, 85°C, 10 mL/g liquid–solid ratio, and 90 min leaching time. The incorporation of H₂O₂ enhanced the leaching efficiency for Ni, Co, and Fe. The redox potential of the solution plays a crucial role in acid dissolution, and H₂O₂ enhances Ni and Co dissolution. Phosphate precipitation facilitated the removal of Fe from the leachate, affording a 96.1% Fe removal ratio and 2.29% Ni loss.