Effects of Feo Levels and Carbon Regulation on Boiling Reactions in Dri Melting Processes

In sponge iron melting within an induction furnace - FeO content, carbon control, and boiling phenomena significantly impact the process. Low FeO content in sponge iron is crucial for efficient energy use and safety, as high FeO can lead to vigorous carbon boil when added to a high-carbon bath, which can be dangerous. Effective carbon control is essential for achieving desired steel composition and minimizing unwanted reactions. Boiling, while sometimes beneficial for refining and reducing impurities, can also disrupt the process if uncontrolled. The availability of suitable raw material especially homogeneous scrap at a competitive price to a steel maker is a challenge. Use of DRI (Direct Reduced Iron or Sponge Iron) as a partial replacement to scrap, to some extent overcome the burden on costing and quality raw material. However, unlike scrap and even pig iron, DRI is characterized by high porosity, low thermal and electrical conductivities. DRI lumps and fines with high FeO, which in turn, poses problems in its melting. Attempts were made to study based on chemical analysis of DRI lumps, fines and pellets w.r.t Fe(M) and FeO to understand the behaviour during melting of DRI in the induction furnace on its carbon control, boiling of the liquid metal, productivity and power consumption. With the limited data available, it is to conclude that, higher proportion of DRI as a replacement to scrap can be used based on market dynamics of scrap & DRI for cost optimization which also improves steel quality. However, due to low Fe (M) and high FeO in DRI fines may pose problems in carbon control and boiling of liquid metal, which can be resolved with process and operational controls while charging DRI fines along with DRI lumps/pellets to maintain FeO in the range 6-7% in the DRI lumps & fines