Research on Dissolution of Vanadium in Acid Leaching Process of Calcified Roasting Clinker of Vanadium Slag

Using the calcified roasting clinker of vanadium slag from a certain company as raw materials,sulfuric acid leaching experiments were carried out to investigate the influences of p H,temperature and time,liquid-solid ratio and stirring rate of leaching process on extraction rate of vanadium.The occurrence state of vanadium in the clinker and its dissolution during leaching process were further studied by SEM and XRD.The results show that vanadium in clinker exists as vanadates,mainly distributing in calcium vanadate,iron oxides solid solution,pseudobrookite phases etc.In the process of acid leaching,the dissolution sequence of vanadium-containing phases is as follows:calcium vanadate ＞ solid solution of iron oxides ＞＞pseudobrookite.The optimum leaching parameters are pH = 0.75,50 ℃ for 10 min with 10:1 of liquid-solid ratio and 500 r/min of stirring rate,where up to 90.21% of vanadium leaching rate can be achieved.