Preliminary Study on the Reductive Leaching of Manganese Ores using FeSO₄/Iron Powder as Reducing Agents under Room Temperature

Abstract

The leaching of manganese (Mn) ore in sulphuric acid (H2SO4) under reductive conditions has been studied. The effects of leaching parameters such as ore/reductant mass ratio, acid concentration, ore particle size, solid/liquid ratio, leaching time and different reductant potential on the maximum recovery of manganese have been investigated. The optimal leaching conditions were ore/reductant mass ratio of 1:3.4, acid concentration of 10% v/v H2SO4, ore particle size of 63-200 µm, particle size of iron powder of –150 µm, solid/liquid ratio of 1:20, and leaching time of 1.5 hours at room temperature. A comparative analysis on the recovery of manganese ore was also investigated under the optimal leaching conditions for two different reductants, iron sulphate (FeSO4) and iron powder. The maximum manganese recoveries at the optimal leaching conditions in the presence of FeSO4 and iron powder are 80.6% and 95%, respectively. The results indicate that manganese can readily be leached during short time at room temperature. Furthermore, iron powder has a stronger reducing power compared to FeSO4 with respect to manganese ore recovery.