Mechanism Study on Extraction Vanadium from Calcification Roasted-Acid Leaching Tailings by Ultrasound-H2o2 Synergistic Treatment

Abstract

There is about 1% vanadium residue in the roasting roasted-acid tailings after industrial vanadium extraction. How to properly treat vanadium-containing tailings has become a hot topic in the environmental field. In this study, a novel vanadium extraction process based on the synergistic treatment of ultrasonic and H2O2 enhanced acid leaching was developed for the highly toxic and valuable calcification roasted-acid leaching tailings. The effect of different experimental conditions on the vanadium leaching rate was explored. The results demonstrated that the vanadium leaching rate reached 72% through synergistic treatment. In contrast, the vanadium leaching rate through conventional treatment was only 44.09%. The synergistic mechanism in leaching experiments was investigated by measuring the content of H2O2. H2O2 and ·OH radicals produced by ultrasonic decomposition can provide higher oxidation potential in different ways, avoiding the formation of intermediate products (VO2+) and accelerating the reaction process. The phase, morphology, element content, and elements with different valences of the experimental samples were analyzed by various characterization methods. The experiment verified that O2 produced by the decomposition of H2O2 under the action of ultrasound contributed to more bubble nuclei. The increased cavitation bubbles enhanced the cavitation in the leaching process and conduced to the virtuous cycle of H2O2 decomposition. This constituted an underlying reason for effectively improving the oxidation potential of the leaching system and destroying the encapsulation. The vanadium recovery technique based on the ultrasonic-H2O2 system exhibited broad application prospects in future industrial tailings management and recovery.

Keywords: Tailings, Vanadium, H2O2, Ultrasonic leaching, Cleaner production