Studies of the Influence of the Percentage Content of Polar Organic Solvent on the Sorption and Separation of Rare Earth Elements Nitrate Complexes on Anion Exchangers

Abstract

Rare earth elements do not occur individually in Nature but in the form of mixtures, which are frequently isomorphic, and in minerals but only in small amounts. Hence, their metallurgy is difficult and extremely expensive. The aim of the present work was to study the influence of the percentage content of a polar organic solvent (CH₃OH, CH₃COCH₃) on the possible selective removal and separation of rare earth elements(III) nitrate complexes by frontal analysis in 95–35% v/v polar organic solvent-x% v/v H₂O-5-10% v/v 1 or 7 M HNO₃ systems on the strongly basic anion exchangers Wofatit SBW × 6% DVB and Wofatit SBK × 7% DVB. The weight and bed distribution coefficients, as well as the number of theoretical plates for individual systems, were determined. The best results were obtained in the 95% v/v CH₃COCH₃-5% v/v 7 M HNO₃ system on Wofatit SBW × 6% DVB. In this case, 2.62 kg Y₂O₃ were purified from a 1% neodymium admixture on 1 dm³ of the anion exchanger.