Kinetics of the alkaline stripping of vanadium(V) previously extracted by Aliquat® 336

The kinetics of the alkaline stripping of vanadium(V) previously extracted by Aliquat® 336 is investigated. The influence of parameters such as the stripping temperature, NaOH concentration and pH at the extraction stage (pHext.) is reported. The limiting step of the stripping process consists in the slow transformation of the extracted polyoxometallate species (e.g., H2V10O284−) into HVO42− or/and VO43− ions. The stripping rate law and the values of the corresponding kinetic constants are similar to those observed for the alkaline decomposition of decavanate in homogeneous phase, although the stripping reaction is biphasic.