Enhance the carbothermic reduction of high phosphorus oolitic hematite with borax

The reduction of high phosphorus oolitic hematite, especially for the accumulation and growth of iron played an important role in subsequent magnetic separation, the influence of borax on which was studied. It was indicated that the mass loss percent was up to 31.11% and the metallization ratio was up to 90.10% when the temperature was 1000 °C and the amount of borax was 6%. SEM and EDS analysis shown that borax could destroy the oolitic structure of the oolitic hematite and decrease melting point of the reduced sample. During the process of reduction, the phases of fayalite (Fe 2 SiO 4 ), hercynite (FeAl 2 O 4 ) and kyanite (Al 2 SiO 5 ) were disappeared, and then the low melting point of sodium salt was formed. The amount and average particle size of iron metal of the reduced samples increased with the increase of borax additive.