Recovery of molybdenum and vanadium with high purity from sulfuric acid leach solution of spent hydrodesulfurization catalysts by ion exchange

Valuable metals, such as Mo, V, Co and Ni together with base metals (Fe and Al) are present in the sulfuric acid leaching solutions of spent hydrodesulfurization catalysts. In order to develop a process to recover pure Mo and V from the solution, batch and continuous ion exchange experiments with strong anionic resin (AG1-x8) have been performed by employing a synthetic sulfuric acid solution. Batch experimental results indicated that the separation of molybdenum and vanadium from the solution with AG1-x8 was possible by adjusting the pH of the solution to 0.5 and 1.6, respectively. Column experimental results verified the complete separation and recovery of molybdenum and vanadium from the solution at the specified pH conditions. Molybdenum and vanadium in the loaded resin was eluted by using NaOH solution. The purity of Mo and V solution after elution was found to be higher than 99%. After elution, AG1-x8 was successfully regenerated by converting its form from hydroxide to chloride by using NaCl solution.