Abstract: | In order to examine the possibility of utilizing Mn ore in the pretreatment process of liquid iron, experiments were carried out in a system with liquid iron and CaO‐SiO2‐MgO‐Al2O3‐FeO slag with additives (Mn ore and Fe2O3+MnO2) in a magnesia crucible at 1673K. When Mn ore was added to the pretreatment slag, decarburization, desiliconization, dephosphorization and desulphurization proceeded simultaneously with the reduction of Mn ore. The reduction rate of MnO and the Mn concentration in the melt increased with increasing initial Si content. The maximum dephosphorization was obtained when the additive consisted of 66.6 mass% Fe2O3 and 33.4 mass% MnO2. The desulphurization ratio increased with increasing the relative amount of MnO2 in the additives. The amount of additives comprising Fe2O3 and MnO2 required for a targeted manganese content could be predicted using the mass balance. Effects of the additives on dephosphorization were also estimated. |