Leaching kinetics of vanadium catalyzed by electric field coupling with sodium persulfate

Electro-catalytic oxidation technology is a clean, efficient process with superb selectivity. This work investigated vanadium leaching in electro-catalytic oxidation and coupling catalytic oxidation by electric field and sodium persulfate from low temperature sodium roasting vanadium slag. The results showed that hydroxyl radical intermediate (MAO(center dot OH)) produced by electric field system could catalyze the selective oxidation of VO3-, and the chemically adsorbed oxygen (MAO((X+1))) could also oxidize low-valent vanadium into high valence. Moreover, electric field had synergistic effect with sodium persulfate on oxidation of low-valent vanadium, making the leaching efficiency reached to 96.52%. On the other hand, electric field could catalyze the formation of persulphates from sulfates, thus promoting the circulation of the reaction system. The kinetics analysis indicated that surface chemical reactions control the leaching process, and the leaching efficiency increased along the increasing of reaction time and temperature. Coupling catalytic leaching had the minimum apparent activation energy, as 11.95 kJ/mol, which followed the kinetic equation of: 1-(1-r)(1/3) = D.exp (-11.95/RT).