Oxidation behavior of vanadium and phosphorus during simultaneous vanadium extraction and dephosphorization of hot metal

Abstract

In this paper, the indirect equilibrium method was used to study the equilibrium distribution ratios of vanadium and phosphorus in the metal phase and the slag phase, and simultaneous vanadium extraction and dephosphorization experiments were carried out under different slag basicity (the mass ratio of CaO to SiO2) conditions to explore the oxidation behavior of vanadium and phosphorus during simultaneous vanadium extraction and dephosphorization of hot metal. The results show that with the increase of slag basicity, the equilibrium distribution ratio of V (lgLV) increases slightly and the equilibrium distribution ratio of P (lgLP) increases significantly. With slag basicity increasing from 0.5 to 2.5, lgLV and lgLP increase from 1.7 to 2.0 and 0.1 to 1.9, respectively. Both lgLV and lgLP decrease with the increase of temperature, and increase with the increase of FeO content. High MgO content is not conducive to vanadium extraction. MnO has less effect on lgLV and lgLP. lgLV increases with the increase of V2O3 content, and decreases with the increase of P2O5 content. lgLP decreases with the increase of V2O3 content, and increases with the increase of P2O5 content. Both lgLV and lgLP decrease with the increase of TiO2 content. When the slag basicity is 1.5, the oxidation rate of vanadium reaches 95% after 10 min of reaction. The total mass transfer coefficient of P is in the range of 0.0040–0.0084 cm/s, and increases obviously with the increase of slag basicity. However, the influence of slag basicity on the total mass transfer coefficient of V is not obvious. Both the rate-limiting step of vanadium extraction and dephosphorization are the mixed mass transfer in the metal phase and the slag phase.