The extraction-chromatographic separation of neodymium from solution from nitric acid with application of sorbents impregnated by N,N,N',N'-tetraoctyldiglicolamide

Abstract

The purpose of this work is investigation of extraction-chromatographic separation of neodymium, as analogue of americium from nitrate solutions of some rare-earth elements (La(III), Eu(III) и Sm(III) with application of sorbents impregnated by N,N,N',N'- tetraoctyldiglicolamide (TODGA). The laboratory and commercial accessible patterns of sorbents, which differences by the method of synthesis, content of TOD-GA, size of granule and nature matrice were investigated. The laboratorial method of the receiving of sor-bents impregnated by TODGA was described. The standard test solutions of Am(III), Nd(III), La(III), Eu(III) и Sm(III definite concentration was used in present investigations. The determination of concentrations of neodymium in investigated solutions was performed by spectrophotometric method with utilization reagents 

of Arsenazo M (λ.= 660 нм ) or personal light absorption of neodymium ( λ.= 796 нм ), depending on con-centrations of neodymium in solutions. The investigations were conducted in frontal and eluted regimes. The significances of dynamic coefficient distribution for neodymium were obtained by means of the standard treatment of frontal dynamic curves. The eluted curves were obtained by the way of desorption of elements after preliminary mapping of definite quantity of analyzed solution on the chromatographic column with the sorbent.

The solutions of 0.05М HNO3, the mixture solutions of 0.05М HNO3 and Н3РО4 (0.01M и 0.1 M), the mixture of solutions of 0.05М HNO3 and 0.01М diethylenetriaminepentaacetic acid (DTPA) were inves-tigated as the desorption agents .

The value of the dynamic coefficients of distribution for neodymium, according to its concentration in the stock solutions, eluent flow rate and size of sorbents granule were received. The distinctive features of extraction-chromatographic separation of neodymium, as analogue of americium from nitrate solutions of rare-earth elements with application of sorbents impregnated by TODGA) were investigated. The relevancy of utilization of Nd(III) in quality analogue of Am(III) was certified by the way of practical identity of the frontal curve for neodymium and americium, which were obtained in identical conditions.

The optimal qualitative and quantitative compositions of sorbents and conditions for effective sorp-tion and desorption of neodymium were found experimentally. It is established that the sorbents wherein as matrices applied of hydrophobic silica gel, possess the greatest opportunity for practical application. In addi-tion, in question sorbent be able selective extract of lanthanum, europium and samarium, that permit of pos-sibility applications for intragroup division of this rare-earth elements.