Effects of smelting parameters on the slag/metal separation behaviors of Hongge vanadium-bearing titanomagnetite metallized pellets obtained from the gas-based direct reduction process

Smelting separations of Hongge vanadium-bearing titanomagnetite metallized pellets (HVTMP) prepared by gas-based direct reduction were investigated, and the effects of smelting parameters on the slag/metal separation behaviors were analyzed. Relevant mechanisms were elucidated using X-ray diffraction analysis, FACTSAGE 7.0 calculations, and scanning electron microscopy observations. The results show that, when the smelting temperature, time, and C/O ratio are increased, the recoveries of V and Cr of HVTMP in pig iron are improved, the recovery of Fe initially increases and subsequently decreases, and the recovery of TiO₂ in slag decreases. When the smelting CaO/SiO₂ ratio is increased, the recoveries of Fe, V, and Cr in pig iron increase and the recovery of TiO₂ in slag initially increases and subsequently decreases. The appropriate smelting separation parameters for HVTMP are as follows: smelting temperature of 1873 K; smelting time of 30–50 min; C/O ratio of 1.25; and CaO/SiO₂ ratio of 0.50. With these optimized parameters (smelting time: 30 min), the recoveries of Fe, V, Cr, and TiO₂ are 99.5%, 91.24%, 92.41%, and 94.86%, respectively.