The Behavior of Phosphorus in the Hydrogen‐Based Direct Reduction—Smelter Ironmaking Route

Abstract

Direct reduction (DR) nowadays relies on high‐grade iron ores, characterized by a high total iron content and low contents of tramp elements. Since their supply is limited and cost‐intensive, applying lower‐grade ores is a relevant topic for the future. Therefore, the behavior of phosphorus in unbeneficiated magnetitic ore during hydrogen‐based DR is studied. Phosphorus remains strongly bound as apatite whether raw or preoxidized fine ore is reduced in a fluidized bed or raw lump ore is reduced under shaft furnace conditions. That is an essential factor for the subsequent melting step, whose behavior is evaluated using thermodynamic calculations and published data from the literature. Although the smelter‐reducing conditions are not ideal for phosphorus withdrawal, one can expect it to be better than the blast furnace. Combining that with the outstanding dephosphorization capacity of the basic oxygen furnace (BOF), the route DR‐smelter‐BOF appears optimal for processing high‐phosphorus iron ores.