Development of a process to produce manganese nanomaterials from low grade ferruginous manganese ores

Abstract

This study has been carried out to explore the feasibility to use the low-grade ferruginous manganese ores to produce manganese nanomaterials (Mn ferrites and ϒ-MnO₂). Ore samples were collected from mines and were ground into <250 μm particle size. These samples were leached using a 1.5 M solution of oxalic acid for 6 h at 90°C. The recovered solution was processed through two different routes. In the first method, leachate was photo-reduced for 8 h and the precipitate was roasted at 350–700°C to produce Mn nano ferrites of magnetic saturation of 18.71 emu/g. In the other route, iron was removed by pH adjustment, and MnCO₃ was produced using NaHCO₃. MnCO₃ was roasted and producing 200 nm manganese oxides nanorods. These results show that the low-grade manganese ore resources can be a potential source for production of manganese nanomaterials to fulfil the growing demand.