Chromium Recycling from Argon-oxygen Decarburization Dust in Hot Metal Pre-dephosphorization Process

The chromium recycling from the stainless steel dust of an argon-oxygen decarburization（AOD）furnace during a hot metal pretreatment process was investigated.Experiments at different temperatures or with different amounts of AOD dusts were carried out in a laboratory furnace equipped with MoSi;heating elements and subsequently industrial experiments were conducted in a stainless steelmaking factory,in order to study the thermodynamic mechanism of C and Si reacted with Cr;O;to get Cr from AOD dust.The results showed that the reaction between C and Cr;O;occurred below 1 572.18 K.Although its reducing ability was weaker than that of Si,C enabled the Cr in Cr;O;in the AOD dust to be recycled using the Si in the slag.By combining the AOD dust added in an earlier stage,the hot metal pretreatment slag added in a later stage could not only recycle Cr from AOD dust but also remove Si,S,and P.Higher hot metal temperatures resulted in higher Cr content and lower remained P concentration in the molten iron.