Synergistic solvent extraction of neodymium form nitric acid medium using Cyanex 302 and D2EHPA

Abstract

In this research, a binary mixture of Cyanex 302 (bis-2,4,4 trimethylpentyl monothiophosphinic acid) and D2EHPA (di-2ethylhexyl phosphoric acid) in kerosene was used for extracting neodymium from nitric acid medium. The different variables affecting the extraction of Nd(III) such as contact time, solution acidity, extractant concentration, and temperature were investigated. Stripping of neodymium ions from the loaded organic phase using HCl, HNO3, and H 2 SO 4 for the re-extraction of neodymium was also carried out. Results indicated that the most efficient reagent for the stripping of neodymium was nitric acid. The extraction reaction of neodymium with the synergistic mixture was determined using graphical method to be NdH 5 A 2 B 6 . The organo-metallic complex containing neodymium was examined by Fourier Transform Infrared Spectroscopy (FT-IR). The values of stoichiometric coefficients and thermodynamic parameters were calculated for this mixture. The extraction was an endothermic process, and the thermodynamic functions, ΔH and ΔS were determined to be 10.532 kJ/ mol and À 123.681 j/mol°K, respectively for the system under study. The Cyanex 302 + D2EHPA system not only increased the extraction efficiency of neodymium but also improved the selectivity significantly. The separation factor of neodymium and praseodymium suggested that this mixture would be of practical value in the separation of neodymium.

Extraction of Cerium from Nitric Acid Medium using Cyanex 302 and Cyanex 572

“…Which D mix indicates the distribution ratio, when the metal is extracted with a combination of two organic solvents, and D A and D B are the distribution ratio of each of the solvents that are used separately. If R is greater than 1, the extraction is synergistic and if it is smaller than 1, it is non-synergistic [4].…”

Extraction of Cerium (III) by a Solvent Extraction Technique Using Diaminododecylphosphonic Acid (DADTMTPA): Experimental, Density Functional Theory and Molecular Dynamic Studies

“…In recent years, the potential applications of phosphinic and phosphonic acids in the recovery of REEs from different aqueous solutions have received considerable attention [6] . As a significant group of extractants (cationic, anionic, solvating) for the extraction of rare earth elements, several extractants such as neutral organophosphorus esters, organophosphorus acid, and amines have been investigated; likewise, Diaminododecylphosphonic acid (DADTMTPA), Cyanex 572, Di(2‐ethylhexyl) phosphoric acid (P204), di(1‐methyl‐heptyl) methyl phosphonate (P350), Cyanex 272, TBP, Cyanex 923, Cyanex 921, Cyanex 302, PC‐88A and di(2‐ethylhexyl)‐phosphoric acid (D2EHPA) [19–29] …”

“…[6] As a significant group of extractants (cationic, anionic, solvating) for the extraction of rare earth elements, several extractants such as neutral organophosphorus esters, organophosphorus acid, and amines have been investigated; likewise, Diaminododecylphosphonic acid (DADTMTPA), Cyanex 572, Di(2-ethylhexyl) phosphoric acid (P204), di(1-methyl-heptyl) methyl phosphonate (P350), Cyanex 272, TBP, Cyanex 923, Cyanex 921, Cyanex 302, PC-88A and di(2-ethylhexyl)-phosphoric acid (D2EHPA). [19][20][21][22][23][24][25][26][27][28][29] The purpose of this study is to cast light upon the best conditions for cerium (III) extraction. Extraction tests are performed using diaminododecylphosphonic acid as an extracting agent.…”