Production of (Mn,Fe)-Carbide Containing Low Phosphorus by Carbothermic Reduction of Mn Oxide and Fe Oxide

Abstract

The dephosphorization process for high phosphorus iron ores have recently been studied employing several methods. However, few researches of phosphorus removal from high phosphorus manganese ores have been carried out compared with those about the high phosphorus iron ores. As a potential approach for the removal of phosphorus contained in the composite, the formation of (Mn,Fe)-carbide by the carbothermic reduction of the oxides of manganese and iron was investigated at 1200 degrees C in H-2 atmosphere employing thermogravimetric analysis (TGA). It was confirmed that the phosphorus did not dissolve into the manganese iron carbide, (Mn,Fe)(7)C-3 even though it has the high reactivity with Fe and Mn. Instead, the phosphorus generated by the decomposition of Ca-3(PO4)(2) reacted with Fe and Mn to form (Fe,Mn)(3)P. According to EPMA line mapping, (Mn,Fe)-carbide and (Fe,Mn)-phosphide coexist in the reduced particle. The current results could be applied for a promising treatment of dephosphorization of high phosphorous ores due to the low solubility of phosphorus in carbide.