Extraction and separation of rare earth metals using microcapsules containing bis(2-ethylhexyl)phosphinic acid

Rare earth elements play an important role in the production, energy, and high technology. Due to the rapid development of industry, the demand for rare earth metals is rising every day. Therefore, it is necessary to improve the extraction of rare earth metals from various sources to meet the demand for these elements. Currently, pyro- and hydrometallurgical technologies are used to extract rare earth metals from an ore and other secondary sources (industrial wastewater, acid drainage mines, etc.). Hydrometallurgical technologies include precipitation, extraction, adsorption, and ion exchange methods. Adsorption is one of the most effective methods for the extraction and separation of rare earth elements. Adsorption methods are highly selectivity to metal ions and have low emissions. However, not all adsorbents are effective in producing the same metal ions. This study provides an overview of the different adsorbents that can be used to extract rare earth elements from aquatic systems. Hydrogels and molecular polymers have been found to be cost-effective methods for high-grade rare earth metals. Further research is needed to ensure the performance of these systems.

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EXTRACTION AND SEPARATION OF HEAVY RARE EARTH(III) WITH EXTRACTION RESIN CONTAINING DI(2,4,4-TRIMETHYL PENTYL) PHOSPHINIC ACID (CYANEX 272)

Solvent Extraction and Ion Exchange ◽

10.1080/07366299808934554 ◽

1998 ◽

Vol 16 (3) ◽

pp. 813-828 ◽

Cited By ~ 31

Author(s):

Zhonghuai Wang ◽

Genxiang Ma ◽

Deqian Li

Keyword(s):

Rare Earth ◽

Phosphinic Acid ◽

Heavy Rare Earth ◽

Extraction And Separation ◽

Cyanex 272

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Solvent extraction of europium(III) from technogenic solutions with the use of surfactants

Тонкие химические технологии ◽

10.32362/2410-6593-2020-15-4-51-58 ◽

2020 ◽

Vol 15 (4) ◽

pp. 51-58

Author(s):

N. V. Dzhevaga ◽

O. L. Lobacheva

Keyword(s):

Rare Earth ◽

Nitric Acid ◽

Aqueous Phase ◽

Ph Value ◽

Rare Earth Metals ◽

Target Component ◽

Acid Solutions ◽

Extraction And Separation ◽

Nitric Acid Solutions ◽

Ph Range

Objectives. The extraction and separation of rare-earth metals is a complicated process that requires a multidisciplinary and detailed investigation. Liquid-liquid extraction with the use of surfactant, along with the thermodynamic analysis of the parameters is considered a promising approach. The extraction and separation of rare-earth metals from low-concentration solutions represents an attractive research opportunity. The extraction of europium(III) from nitric acid solutions in the form of dodecyl sulfates has been experimentally studied. This work focuses on the study of fundamental and alternative sources of rare-earth metals and their extraction and separation.Methods. The extraction was performed on a top drive ES-8300 D equipment for 30 min at about 700 rpm. Infrared spectroscopy (Nicolet 6700 spectrometer) was used to determine the type of salts extracted into the organic phase. Extraction was studied in solutions with single cations and with a combination of the target element and interfering cations. For the latter, the concentrations of extracted elements in the aqueous phase were determined by optical emission spectroscopy with inductively coupled plasma on an ICPE-9000 (Shimadzu) spectrometer. The spectrometer was calibrated using standard samples for ICP CertiPUR (Merck).Results. The dependence of the distribution and separation coefficients of rare-earth metals during extraction on the pH value of the aqueous phase at equilibrium was investigated. Moreover, the form in which the elements are extracted was analyzed based on thermodynamic parameters. The minimum concentration of the target component in the aqueous phase was observed at pH 4.0. In general, the dependence of the distribution coefficient on the pH value of the medium is poorly expressed over the entire range of the pH range of the water phase. Based on the spectra of spent and pure isooctyl alcohol, it was concluded that europium dodecyl sulfates are extracted into the organic phase as Eu(C12H25OSO3) 3 solvates.Conclusions. The extraction of europium(III) from nitric acid solutions in the form of dodecyl sulfates was demonstrated. The advantages of the proposed method are the possibility of selective extraction of the target component from dilute solutions and the use of an easily available surfactant (sodium dodecyl sulfate). The efficiency of extraction of europium dodecyl sulfates was maximal in the pH range from 2.0 to 7.5, which reflects a weak dependence on the acidity of the aqueous phase. In addition, in the highly alkaline pH region, the extraction efficiency is reduced.

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