Enhanced Recovery of Nickel and Cobalt from Limonitic Laterite Ore: Optimization and Kinetics of Atmospheric Sulfuric Acid Leaching

A practical process for extracting nickel and cobalt from limonitic laterite ore using sulfuric acid as a leaching agent is proposed. The objective is to enhance the efficiency and sustainability of the leaching process in the mining industry. The variables of particle size, temperature, and sulfuric acid concentration are optimized using Response Surface Methodology (RSM) analysis. The RSM analysis enabled identification of the optimal conditions for maximum metal recovery from laterite ore. The results show that under the optimal conditions of 10 M H<inf>2</inf>SO<inf>4</inf> and a temperature of 90 °C, achieving recovery percentages of 49.98 for nickel and 82.49 for cobalt. The stirring speed (400 rpm) and the solid-to-liquid ratio (0.1) were kept constant throughout the experiments. Additionally, the study of leaching kinetics reveals that the leaching process of Ni and Co in laterite ore materials was predominantly affected by internal diffusion control, specifically solid product layer diffusion. The study highlights the importance of optimizing operational parameters to improve laterite leaching efficiency. © The Minerals, Metals & Materials Society 2025.