Estimation of vanadium removal from calcification roasting-acid leaching tailings using ultrasonic-H2C2O4 synergistic technology

Metal vanadium smelting produces roasting-acid leaching tailings containing approximately 1% vanadium residue, making it challenging to store and recycle these waste tailings in an environmentally friendly manner. To address this issue, a clean method called ultrasonic-enhanced oxalic acid complexation was proposed in this study for efficient removal of residual vanadium. Under the optimal conditions, the removal rate of vanadium and the decomposition rate of oxalic acid reached 86.88% and 23.6%. An in-depth analysis on the experimental results in combination with thermodynamics found a virtuous cycle chain induced by ultrasonic cavitation. Ultrasonic waves facilitated the decomposition of oxalic acid, producing more CO2 to supplement the limited cavitation bubble nucleuses. Consequently, the cavitation effect was strengthened, leading to an increased yield of OH radicals. This resulted in a continuous improvement in the oxidation environment. Furthermore, the enhanced virtuous cycle generated by ultrasonic cavitation produced powerful microjets that facilitated the stripping and dispersion of mineral particles. Overall, the oxalic acid-ultrasonic leaching technique offers a clean and efficient technology for separating vanadium.