China Nonferrous Metallurgy

To actively respond to the national carbon peaking and carbon neutrality goals, it is of great significance to develop the purification and separation process of highly efficient and selective vanadium shale acid leaching solution for vanadium extraction from vanadium-shale. In this study, the vanadium and impurity separation indexes of the new hydroxoxime extractant Mextral 984H and the organophosphorus extractant P204 were compared from the solution pH value, the concentration of impurity ions (Fe, Al and Mg) and strippant. The results showed that the optimal extraction pH value of Mextral 984H was 0.5~1.5, and the optimal extraction pH value of P204 was 1.5~2.4. The vanadium complex formed by Mextral 984H was more stable than P204, with shorter vanadium-oxygen bond lengths and larger molecular gaps, making it easier for the vanadium complex to stabilize in an acidic environment. Fe(III), Al(III) and Mg(II) had less influence on the extraction of V(V) by Mextral 984H. For P204, Fe(III) had a greater effect on the extraction of V(IV) and controlling the concentration of Al(III) and Mg(II) below 10g/L reduced the co-extraction rate of Al(III) and Mg(II). The single-stage stripping percentage of the organic phase loaded with Mextral 984H by sodium carbonate and oxalic acid were both over 80%.