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

Abstract

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.