Abstract: High-phosphorus oolitic hematite treated with coal-based reduction technology can have good technical-economic indicators， but the role of additives such as CaO and Na₂CO₃ in the reduction process still needs to be further studied. The influence of reduction temperature， reduction time， mole ratio of C to O on reduction index was investigated， taking high-phosphorus oolitic hematite from Western Hubei as research object. The results showed that the appropriate reduction conditions were the reduction temperature of 1523K， the reduction time of 30 min and mole ratio of C to O is 2.0， the metallization degree of the reduced products was 86.21%， the iron grade of magnetic separation was 91.69%， and the recovery was 92.23%. The effects of CaO and Na₂CO₃ dosage on separation indexes was investigated on the optimum coal-based reduction conditions， the chemical composition analysis and X-ray diffraction （XRD） were used to investigate dosage of CaO and Na₂CO₃ on separation index of high-phosphate oolitic hematite， dephosphorization and phase transition. The addition of CaO and Na2CO3 can inhibit the formation of fayalite in reduction process， effectively reduce the phosphorus content in concentrate and improve the iron recovery. CaO can react with SiO₂ and Al₂O₃ in the samples to form high-melting-point silicates such as wollastonite and gehlenite， which is not conducive to the improvement of iron grade. Na2CO3 can react with SiO₂ and Al₂O₃ in the samples to form low-melting-point silicate such as albite， which is conducive to the improvement of iron grade.

Key words: High-phosphorus oolitic hematite, Coal-based reduction, Additive, CaO, Na₂CO₃, Phrase changes, Dephosphorization