| Summary: | Manganese nodules are an attractive source of base metals and critical and rare elements and are required to meet a high demand of today’s industry. In previous studies, it has been shown that high concentrations of reducing agent (Fe) in the system are beneficial for the rapid extraction of manganese. However, it is necessary to optimize the operational parameters in order to maximize Mn recovery. In this study, a statistical analysis was carried out using factorial experimental design for the main parameters, including time, MnO<sub>2</sub>/Fe<sub>2</sub>O<sub>3</sub> ratio, and H<sub>2</sub>SO<sub>4</sub> concentration. After this, Mn recovery tests were carried out over time at different ratios of MnO<sub>2</sub>/Fe<sub>2</sub>O<sub>3</sub> and H<sub>2</sub>SO<sub>4</sub> concentrations, where the potential and pH of the system were measured. Finally, it is concluded that high concentrations of FeSO<sub>4</sub> in the system allow operating in potential and pH ranges (−0.2 to 1.2 V and −1.8 to 0.1) that favor the formation of Fe<sup>2+</sup> and Fe<sup>3+</sup>, which enable high extractions of Mn (73%) in short periods of time (5 to 20 min) operating with an optimum MnO<sub>2</sub>/Fe<sub>2</sub>O<sub>3</sub> ratio of 1:3 and a concentration of 0.1 mol/L of H<sub>2</sub>SO<sub>4</sub>.
|
|---|
