Seyyed M. Seyyed Alizadeh Ganji - School of Mining, Petroleum & Geophysics Engineering, Shahrood University of Technology, Shahrood, Iran
S. Z. Shafaie - School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran
N. Goudarzi - Faculty of Chemistry, Shahrood University of Technology, Shahrood, Iran

This work was aimed to evaluate and compare the performances of the solvents D2EHPA (Di-(2-ethylhexyl) phosphoric acid), Cyanex 272 (bis (2,4,4-trimethylpentyl) phosphinic acid), and a mixture system of D2EHPA and Cyanex272 in the separation of some rare earth elements (REEs) including lanthanum, gadolinium, neodymium, and dyspersym from a nitric acid solution. The results obtained showed that Cyane272 had the lowest separation factor in the separation of Dy, La, Nd, and Gd from each other. Also it was found that a mixture system of D2EHPA and Cyanex272 had the best performance in the separation of the investigated REEs, owing to the higher separation factors for Dy/Nd and Dy/Gd, as well as the lower extraction efficiencies for Gd (64.54%), La (30.07%), and Nd (26.47) from Dy (99.92). It was also determined that the separation factors forDy/Nd and Dy/Gd were 720.05 and 3640.27, respectively, using their mixture system.

Rare Earth Elements (REEs), Separation Factor, D2EHPA, Cyanex272, Mixture System