Gasificating Dephosphorization During the Carbothermic Reduction of Medium Phosphorus Iron Ore Concentrate in the Presence of Na2CO3 and SiO2

To relieve the increasing lack of high-quality iron ore, the medium and high phosphorus refractory mineral resources are being developed worldwide due to the rich storage. The novel method of pre-reducing sinter process was applied to remove phosphorus, characterized by reduced atmosphere, high temperature, and negative pressure. For medium phosphorus Bayan Obo iron ore concentrate, the effect of the carbon mixing ratio, reduction temperature, and time on phosphorous gasification and iron metallization during carbothermic reduction was investigated using XRD, FESEM-EDS, and FactSage software, in the presence of Na2CO3 and SiO2. The optimal carbothermic reduction is conducted at 1050 ℃ for 60 min with 20 wt% carbon mixing ratio. The corresponding gasificating dephosphorization and iron metallization are 31% and 96%, respectively. Moreover, the further increased carbon mixing ratio and reduction temperature causes the large absorption of reduced phosphorus gas into metallic iron. Notably, the above result provides data support for pre-reducing sinter process.