Study on dephosphorization for ferromanganese melt and its oxygen potential in dephosphorization process

When BaCO370%-MnO25%-(Fe2O3+BaF2)25% fluxes are used to dephosphorize for blast furnace ferromanganese, the maximum dephosphorization rate(50%) corresponds to Fe2O3 8% in flux ,the relations between the oxygen potential in ferromanganese melt and carbon activity , silicon activity as well as manganese loss (△) in the melt are ×1012/Pa=-1.542+0.018×aC,×1012/Pa=-1.284+1.366×aSi,×1012/Pa=1.737+0.565×Δ respectively. When blast furnace ferromanganese is dephosphorized by BaCO370%-BaF210%-MnO2 5%-Fe2O315% fluxes , the maximum dephosphorization rate (41%) and the highest oxygen potential(2.31×10-12 Pa) in ferromanganese melt correspond to 15 min treatment . The results of dephosphorization experiments show that the oxygen potential in ferromanganese melt is controlled by silicon-oxygen reaction in the melt. In order to dephosphorize for ferromanganese and to prevent manganese from oxidation the oxygen potential in ferromanganese melt has to be controlled at or under 1.737×10-12 Pa .