DISTRIBUTION OF NEODYMIUM(Ⅲ) BETWEEN ACIDIC AQUEOUS NITRATE SOLUTIONS AND ORGANIC SOLUTIONS OF Di-(2-ETHYLHEXYL)-PHOSPHORIC ACID IN KEROSENE AT Low METAL CONCENTRATION

摘要

The solvent extraction of neodymium (Ⅲ) from 0.1M nitrate solutions by di-(2-ethylhexyl)phosphoric acid (D2EHPA) in kerosene has been characterized at low metal concentration. The influence of the diluent on the speciation of the system has been studied by graphical and numerical analysis of the metal distribution data and compared to the results obtained in hexane. Nd(Ⅲ) was extracted by ion-exchange reactions via the species NdA_3·3HA, Nd_3·2HA and NdA_3 in the organic phase, with logarithm of stability constants equal to 15.42, 12.32 and 4.12 respectively.