Effect of Roasting Characteristics of Vanadium-Rich Slag on Its Vanadium Leaching Behavior

Abstract

The effect of the roasting characteristics of vanadium-rich slag on its vanadium leaching behavior was investigated to enable its effective utilization. Thermodynamic analysis of the sodium roasting of vanadium-rich slag was performed for the first time. The effect of the roasting temperature, roasting time, quantity of sodium carbonate (Na2CO3) added, and particle size of the raw material on the vanadium leaching was studied. The results showed that the oxidation reactions of vanadium oxides, fayalite (Fe2SiO4), and vanadium-iron spinel (FeV2O4), and the formation of sodium vanadate were feasible within the roasting temperature range. The sodium roasting was significant for the subsequent vanadium leaching process. The optimum process conditions for sodium roasting were roasting temperature of 850°C, roasting time of 60 min, Na2CO3 addition of 20%, and particle size of − 74 μm, resulting in an ideal vanadium leaching ratio. The results of the current study provide experimental evidence to establish a correlation between the roasting characteristics of vanadium-rich slag and its vanadium leaching behavior, as well as a theoretical and technical basis for effective utilization of vanadium-rich slag.