Cavitation/hydrogen peroxide based AOPs enhanced chemical oxidation for releasing vanadium from landfilled metallurgical residues

Silicate inclusions represent the predominant form of vanadium within the metallurgical residues generated as a by-product of vanadium production, commonly referred to as landfilled metallurgical residues (LMR). The presence of these silicate inclusions presents a significant challenge in the effective separation and recovery of vanadium from such residues. This study focuses on the utilization of cavitation/hydrogen peroxide-based Advanced Oxidation Processes (CH-AOPs), to facilitate the enhanced chemical oxidation for releasing vanadium from LMR in a weak H+-F− system. The optimization results of Box-Behnken design (BBD) show that, under the conditions of sodium fluoride dosage of 2%, reaction temperature of 60 °C and ozone flow rate of 300 ml/min, the actual leaching rate of vanadium and the leaching rate predicted by the quadratic regression model were 69.1% and 69.04%, the error between the two was less than 0.10%. The kinetic activation energy of vanadium leaching is 31.09 kJ/mol, which is within the range of mixed control. The application of this approach weakens the role of fluoride ions and hydrogen ions in the reaction system, thereby reducing the required amounts of concentrated sulfuric acid and sodium fluoride. It was observed that compared to treatments involving ozone alone or ozone/cavitation, the application of CH-AOPs led to enhanced efficiency in the decomposition of ozone within the system.