Abstract
An environmentally-friendly method based on hydrometallurgy was examined for the extraction of Vanadium (V) from vanadium steel slag using a mixture of organic acids. This method was utilized to mimic a bioleaching process of vanadium slag with microorganisms such as Pseudomonas putida which produce organic acids that act as leaching agents. A slag roasted with sodium carbonate was leached using a mixture of Gluconic, Citric and Oxalic acid (mixed in equal volumes of similar concentration) under the growing conditions of the microorganisms considered. The impact of various parameters such as acid concentration, solid-liquid ratio, particle size and temperature were examined. It was discovered that leaching with the mixed organic acids in the optimum conditions gave a V dissolution of 78%. The kinetics of the leaching process revealed that the V leaching process was an intermediate between a diffusion and a chemically controlled reaction with an activation energy of 34 kJ/mol during the initial ten minutes of the leaching process. After 10 minutes, the dissolution is a diffusion controlled reaction with an activation energy of 13kJ/mol. The main impurity (Al) was remarkably co-leached at an average of 66%.