Innovative Recovery of Vanadium from Vanadium-Chromium-Reducing Residue by Ultrasonic-Assisted Alkaline Leaching

Vanadium-chromium-reducing residue (VCRR) was generated using a sodium-roasting-leaching-precipitation process for vanadium recovery. The retained vanadium and chromium could be utilized for an important sources. Here, a novel process was developed that utilized ultrasonic to enhance the alkaline leaching process of vanadium from VCRR. The effect of various parameters was studied, and a corresponding kinetic model was established. It was found that the maximum vanadium leaching efficiency of 96.9% was obtained at optimum reaction conditions: reaction temperature of 90 degrees C, reaction time of 60 min, dosage of NaOH at m(NaOH)/m(VCRR) = 0.5 g/g, liquid-to-solid ratio of 5 mL/g, stirring rate of 500 rpm, and ultrasonic frequency of 40 kHz. The leaching kinetics analysis showed that the leaching process was controlled by diffusion through a product layer both in normal leaching and ultrasonic leaching. The calculated Ea for vanadium leaching out was 20.56 kJ center dot mol-1 for ultrasonic leaching and 23.06 kJ center dot mol-1 for normal leaching. Ultrasonic-assisted leaching might be a potential industrial application technique for recovery of valuable metals from metal ores.