Selective Reduction of Phosphorus from Manganese Ore to Produce Ferromanganese Alloy with Low Phosphorus Content

The authors proposed the selective reduction of P from steelmaking slag to enable the recycling of steelmaking slag for the sintering process, and for the extraction of P and Mn separately. By decreasing the basicity of the slag and increasing the temperature of the reduction, Fe and P were reduced to the metal, while most of the Mn remained in the slag. In this study, this selective reduction technique was applied to a kind of Mn ore to remove P. The influences of the different mixing ratios of graphite, SiO₂, and pig iron as well as the temperature on the reduction behavior were investigated. By adding SiO₂ as a slag modifier to produce an acidic slag with a low melting temperature and adding graphite and pig iron as a reductant and receiver, respectively, the selective reduction of P without the reduction of Mn was achieved for Mn ore. When the slag obtained after the selective reduction of Mn ore was used in the smelting reduction process to produce the ferromanganese alloy, a significant decrease in the P content of ferromanganese was estimated through a mass balance calculation. Therefore, the selective reduction of P from Mn ore has the potential to produce high-grade ferromanganese alloys with low P content.