On Increasing Mn Recovery During Production of Mn-Based Stainless Steel
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Recovery of Mn in steel making process depends on various processing parameters such as temperature, flow rate ratio of oxygen and argon gas in AOD process, carbon content, slag basicity, and V-ratio, Si content etc. The effect of these process parameters on Mn recovery in Mn-based stainless steel production is studied and optimized to maximize Mn recovery. It is observed that highest Mn recovery is achieved when slag basicity is maintained in the range of 1.7–1.8 and V-ratio is kept at 1.5. Further, it is noted that at high temperature, recovery of Mn is less because loss of Mn due to oxidation increases exponentially with the increase in temperature. Maximum Mn recovery is observed at 1585 °C bath temperature. Reduction of MnO with coke forms CO2 gas and free Mn in the melt. To maximize recovery of Mn in stainless steel, it is of paramount importance that oxidation of Mn is reduced and reduction of MnO is accelerated. Oxidation of Mn is minimized by reducing the flow rate of oxygen and reduction of MnO is accelerated by adding adequate amount of coke to the molten charge.
KeywordsMn recovery Slag basicity V-ratio Foamy slag Mn based stainless steel Nitrogen oxygen decarburization (NOD)
Authors are thankful to the technical team at Shah Alloys Ltd., Ahmedabad, India for supporting us in performing various production trials and providing valuable suggestions throughout this project work.
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