Novel Process of Reduction Roasting Manganese Ore with Sulfur Waste and Extraction of Mn by Acid Leaching

Manganese dioxide is typically reduced to a bivalent state before being extracted; here, sulfur considered an efficient reductant and sulfur–based reduction has been industrialized in China. In this study, the reaction mechanism between MnO2 gaseous was investigated. Thermodynamically, of by feasible. The predominant phase diagram as functions temperature input S2(g) fraction S2–MnO2 system calculated. Experimental validation showed that stepwise low-valence manganese oxides sulfate. composition roasted products complex, MnS inevitably formed. valence well microstructure during roasting were also investigated X-ray photoelectron spectroscopy (XPS) scanning electron microscopy–energy-dispersive (SEM–EDS). process could be described unreacted nuclear model. extracted sulfuric acid solution after waste. acid, 95.2 wt% Mn extraction achieved, using 450 °C, time 30 min, S2/MnO2 molar ratio 0.40. With same conditions, low Fe achieved. On other hand, deionized water, 24.3 confirming formation MnSO4.