Investigation of the extraction of vanadium and molybdenum from vanadium production waste by alkaline leaching with sodium hypochlorite

Vanadium and molybdenum are critical metals widely used in steel production, alloys, and green energy technologies. With growing global demand, efficient recycling methods for industrial waste are essential. This study investigates the extraction of vanadium (3.44%), molybdenum (0.75%), and nickel (8.82%) from vanadium production waste using hydrometallurgical methods. Optimal leaching conditions were determined through experiments with sodium carbonate (Na₂CO₃) and sodium hydroxide (NaOH) solutions. The highest vanadium recovery (50.56%) was achieved with 1% Na₂CO₃ at 80°C, while molybdenum extraction reached 56.33% with 3% Na₂CO₃. Alkaline leaching with 0.5% NaOH and sodium hypochlorite (NaClO) at 25°C improved vanadium recovery to 88% and molybdenum to 67.7%. However, increasing the temperature to 85°C led to nickel vanadate (Ni₃V₂O₈) formation, reducing vanadium extraction efficiency. X-ray phase analysis confirmed the presence of aluminium oxides (Al₂O₃), nickel compounds, and vanadium phases in the residues. A proposed processing scheme ensures high metal recovery while minimising environmental impact through closed-cycle operations. This study advances sustainable metal extraction from industrial waste, offering a cost-effective and eco-friendly solution for resource recovery