Study on extraction mechanism of neodymium from nitric acid media using D2EHPA and Cyanex 301

In this research, solvent extraction of neodymium from nitric acid media using D2EHPA and Cyanex 301 was investigated. Different parameters affecting on the extraction of neodymium such as contact time, pH, nitrate ion, extractant concentration and temperature were studied. The effect of various acids on the stripping of organic phase was also investigated. Results indicated that the addition of Cyanex 301 to D2EHPA in the organic phase will be improved the extraction efficiency of D2EHPA. The best synergistic enhancement factor was obtained 9.3 in the fraction mole of 0.3 for Cyanex 301. The effect of equilibrium pH on the distribution ratio of neodymium showed that two moles of H+ were released during the extraction process. The variation of extractant concentration on the extraction of neodymium at fixed concentration of other extractant indicated that the extracted complex was as NdH5A2B6(o). Finally, extraction mechanism, equilibrium constant, and thermodynamic parameters (H, S, and G) of extraction process were investigated.