Slag formation path in converter smelting process of semi-steel containing chromium

Abstract

Aiming at the high-efficiency utilization of vanadium–titanium magnetite with high chromium content, a slag formation path in the converter smelting process of semi-steel containing chromium was proposed. The influences of MnO and Cr₂O₃ on the melting characteristics of converter slag were calculated through FactSage. The effects of components and temperature on the equilibrium distribution ratio of P, Cr between molten CaO–SiO₂–FeO–MgO–MnO–Cr₂O₃–P₂O₅ slags and molten steel was obtained by the indirect experimental method and the regular solution model. The results show that the liquidus region and the proportion of liquid phase decrease with the increase of Cr₂O₃ content in steel slag. The increases of basicity conduces to dechromization and dephosphorization. The L _Cr increased continuously with increasing FeO content and the influence of the oxidization of steel slag on the L _Cr is greater than L _P. Both L _P and L _Cr decrease distinctly with the increase in temperature. The slag formation path for the smelting process of semi-steel containing chromium is as follows: 17wt-%CaO–16wt-%SiO₂–67wt-%FeO→25wt-%CaO–20wt-%SiO₂–55wt-%FeO→57wt-%CaO–17wt-%SiO₂– 6wt-%FeO.