Green process for recovery of vanadium from hazardous spent contact process catalyst by oxalic acid: kinetics and mechanism

This work aims to develop a green method for the recovery of vanadium from spent contact process catalyst (SVC) with 6–7% V2O5. The efficiency of leaching was evaluated using oxalic acid by varying pulp density, time, particle size, and temperature. It is found that with 0.25 M of oxalic acid, almost 98% V, 42% Fe and 24% Al was recovered in 2 h at 323 K and pulp density of 20% using <50 µm particle size. The leaching kinetics and mechanism was further established by characterizing the feed and residues by XRD and SEM. Separation of vanadium was performed using ion-exchange and precipitation.