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

Given the surging demand for nickel and cobalt fueled by the rapid expansion of the electric vehicle industry, it is imperative to develop efficient and eco-friendly metallurgical routes for extracting these metals. This work introduces a sustainable and effective method for nickel and cobalt extraction from Ni-Co-Fe alloy powder, which was obtained from a limonitic laterite ore through selective reduction-magnetic separation. The leaching efficiencies of Ni, Co and Fe were 89.4%, 94.8% and 96.5%, respectively, under the leaching conditions of 3M H2SO4, 85°C and a liquid-to-solid ratio of 10 mL/g for 90 min. The incorporation of H2O2 enhanced the leaching efficiencies of Ni, Co and Fe. The redox potential of the solution plays a crucial role in the acid dissolution, with H2O2 modification enhancing Ni and Co dissolution. Phosphate precipitation facilitated the removal of iron from the leachate, achieving 96.1% iron removal ratio with only a 2.26% nickel loss.