Solvent extraction of Nd using organo-phosphorus extractants from chloride media

INTRODUCTIONA comparative study on solvent extraction of neodymium using both acidic and neutral form of phosphonic, phosphinic and thiophosphinic acid extractants from chloride media has been carried out. The extractants used for the study were PC88A, Cyanex 272 and Cyanex 302. RESULTSIn this study the effect of different parameters such as equilibrium pH, extractant concentration, A:O phase ratio and temperature on Nd extraction was investigated. With increasing pH and extractant concentration the percentage extraction of Nd increased for all these extractants. The percentage extraction of Nd was maximum with NaCyanex 302. So after optimizing the extraction and stripping conditions, the McCabe-Thiele plots for neodymium extraction and stripping were constructed with 0.025molL(-1) NaCyanex 302 at pH4.2 and 0.08 (v/v)% sulphuric acid, respectively. CONCLUSIONThe McCabe-Thiele plots indicated two stages for both extraction and stripping at A:O ratio of 1. The extracted species was determined to be NdA(3.)5HA. The thermodynamic parameters such as H, S and G were calculated. The loading capacity of NaCyanex 302 for Nd and the synergistic coefficient of NaCyanex302 with NaCyanex272 and NaPC88A were determined. The effect of different salts such as NaCl, NaNO3 and Na2SO4 on extraction of Nd was also studied. (c) 2014 Society of Chemical Industry