Effective solvent extraction of La, Ce and Pr from hydrochloric acid with a novel extractant N,N-dihexyloxamic acid

Abstract

BACKGROUND For the first time, N,N‐dihexyloxamic acid (HA) has been developed to extract La, Ce and Pr from hydrochloric acid solution in present work. RESULTS La, Ce and Pr can be extracted by HA in the pH range 1.3 to 2.0 using heptane as diluent. The extraction order was La < Ce < Pr. The separation factors were calculated to be 1.8 for La/Ce and for Ce/Pr. Based on slope analysis, all the rare earths (REs) were loaded in the form of REsCl0.6A2.4(HA)0.6 that may be a statistical expression of a mixture of complexes. Stripping tests showed that the loaded organic phase can be stripped by hydrochloric acid at medium acidity. CONCLUSION The extraction results obtained in the study suggest that N,N‐dihexyloxamic acid could serve as an effective extractant for La, Ce and Pr. © 2016 Society of Chemical Industry

Improved Extraction of Rare Earths of La, Ce, Pr, and Nd by Optimizing the Structure of Phenoxyacetic Acid

“…Our previous research confirmed that chloride ions can interact with REs, causing chloride ions to compete with HA for Res. [34] This adverse effect reached saturation when the chloride ion concentration was 0.13 mol⋅L À 1 . According to the above results, the extracted complexes can be expressed as REs(A) 3 and the extracting process can be described as:…”

“…[28][29][30][31][32][33] Previously, we focused on the structure optimization of carboxylic acid extractant, and developed a novel type of extractant, namely N,N-dihexyloxamic acid, which is a medium strong acid and exhibits an excellent extraction ability than CA12. [34] Encouraged by this progress, we synthesized another interesting extractant, namely 2-(2-heptanoylphenoxy)acetic acid (HA), which is supposed to have better extraction capacity than CA12 without additional additives. The improvement of extraction capacity of HA can be attributed to the optimization of molecular structure and the 2-heptanoyl group in HA may strengthen the affinity of phenoxyacetic carboxylic acid group to REs.…”

Hydrometallurgical Recovery and Process Optimization of Rare Earth Fluorides from Recycled Magnets

“…As a part of the impurities encountered in REE recovery, some of the leached Fe is also recovered as ammonium jarosite in the final REF product. To remove this impurity, the final product form is subjected to high temperature (250-500 • C) to decompose the ammonium jarosite [18][19][20][21] For solvent extraction and ion exchange, different cationic, anionic and solvating extractants such as di (2-ethyl-hexyl) phosphoric acid (D2EHPA), dialkyl phosphonic acid (Cyanex 272), 2-ethyl-hexyl phosphonic acid mono-2-ethyl-hexyl ester (PC 88A), neodecanoic acid (Versatic 10), tributyl phosphate (TBP), and tricaprylylmethylammonium chloride (Aliquat 336) have been reported for the separation of REEs from solution with D2EHPA being more commonly used with nitrate, sulfate, chloride and perchlorate solutions, PC 88A with chloride solutions, and TBP with nitrate solutions [22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Interestingly, many of the same chemical types used as solvent extractants are also used in solid form as ion-exchange resins from the same type of leaching solutions [23,24,28,32].…”