关键词: 高铁赤泥, 直接还原, 添加剂, 海绵铁

Abstract: The process of coal-based direct reduction-magnetic separation for producing sponge iron from ferric red mud can realize effective iron enrichment.In the reduction process, the generation of 2FeO·SiO₂ and FeO·Al₂O₃ can hinder the reduction of the iron oxides in red mud.Pre-roasting can promote the reduction of red mud, but in the presence of additives, the effect of pre-roasting will not be so evident.When used as additives in the reduction process, Na₂CO₃ will produce basic oxides that can react with acidic oxides, and CaF₂ can reduce the melting point and viscosity of compound generated through solid phase reaction, thus improving the reduction conditions.When 3% Na₂CO₃ and 3%CaF₂ are added, at a reduction temperature of 1 150 ℃ and a reduction time of 3 h, sponge iron can be produced with a metallization rate of 92.79%, an iron grade of 89.57% and an iron recovery of 91.15%.

Key words: Ferric red mud, Direct reduction, Additives, Sponge iron