Microemulsion leaching of vanadium from sodium roasted vanadium slag by fusion of leaching and extraction processes

In this work, the fusion of leaching and purification steps is realized by directly using microemulsion as the leaching agent. The DEHPA/n-heptane/NaOH microemulsion system has been established to directly leach vanadates from sodium roasted vanadium slag. The effect of leaching arguments on the leaching efficiency is investigated, including the molar ratio of H₂O/NaDEHP (W), the DEHPA concentration of, solid/liquid ratio, stirring time, and leaching temperature. In optimal situations, the vanadium leaching efficiency could attain 79.57%. Both the XRD characterization of the leaching residue and the Raman spectrum of the microemulsion before and after leaching demonstrate the successful entrance of vanadates from sodium roasted vanadium slag into the microemulsion. The proposed method has realized the leaching and purification of vanadates in one step, which significantly reduces the production cost and environmental pollution. It affords new ways of thinking about the greener recovery of valuable metals from solid resources.