Liquid–Liquid Equilibrium in an Extraction System Based on Polyvinylpyrrolidone-3500 and Sodium Nitrate

Luminophores that used, for example, in fluorescent lamps, contain a large number of rare earth elements. Therefore, the processing of waste equipment containing luminophores is a rational approach to the obtaining of rare-earth metals, firstly, from the economics point of view, since they have a high cost, and secondly, from the ecological point of view, since environmental pollution will not occur. The cheapest way to extract rare earth elements from waste products is to dissolve them in strong acids and the following reprocessing by liquid extraction methods. In this case, neutral or ion exchange extractants (tributyl phosphate, di(2-ethylhexyl)phosphoric acid and quaternary ammonium salts) are used, which show high extraction ability and, in some cases, selectivity. Their applying is associated with the use of non-polar organic solvents, which contradicts the principles of «green» chemistry. A good and promising alternative to organic solvents can be aqueous two-phase systems, which have already proved themselves as low-toxic, but highly effective systems for the separation of a number of metals. Thus, in this work, we performed an experimental study of the interphase distribution of Eu(III), Gd(III), and Tb(III) in two-phase systems based on water-soluble polymers with or without the introduction of traditional organic extractants as an additive. The possibility of using such ATPS as a «green» solvent for traditional extragents for Eu(III), Gd(III), and Tb(III) extraction has been shown.

Section: Introductionmentioning

confidence: 99%

Extraction of Eu(III), Gd(III), and Tb(III) in aqueous two-phase systems based on polyethylene glycol 1500-NaNO3-H2O with the addition of extractants (D2EHPA, TBP, TOMAN)

Fedorov

Левина

Fedorova

2022

“…Two-phase water systems based on water-soluble polymers and inorganic salts can be an effective replacement for classical extraction systems. [19][20]. So, a system based on poly(ethylene glycol) and polypropylene glycol has shown its effectiveness for the transition metal ions without complexing agents [21][22][23], and with the addition of traditional extragents: Aliquat 336 [24], trioctylmethylammonium thiocyanate [25], potassium thiocyanate [26].…”

Section: Introductionmentioning

confidence: 99%

Vanadium(IV) ions extraction in the aqueous two-phase system based on poly(ethylene glycol)

Левина

Fedorova

2022

Vanadium has found wide applications in various industries: metallurgy, electronics, batteries, and others. This element, being dispersed, does not form its minerals and, therefore, is mined along the way. An alternative approach of vanadium extraction is to separate it from heavy oil, by flushing the oil with strong acids solutions and further hydrometallurgical processing. The existing methods of oil dehydration solutions processing for the vanadium extraction are not perfect - they do not meet the “green” chemistry principles. Thus, we investigated V(IV) ions extraction in the aqueous two-phase system (ATPS) based on poly(ethylene glycol) 1500 (16.3wt%) – NaNO3 (36wt%) – H2O. The dependences of V(IV) extraction efficiency on phases time contact, and dependences V(IV) distribution coefficients on salt phase acidity have been obtained. This system is shown to be a prospective solution for the vanadium(IV) recovery from acidic waste steams problem as it is possible to extract vanadium with an efficiency of more than 81.6% per one extraction step (the distribution coefficient of vanadium (IV) was 4.84).

“…At the moment there are some main directions of a modern extraction technologies development. Voshkin et al have conducted researches on the new extraction systems, e.g., aqueous two-phase systems (ATPS) [9][10][11] that are able to reduce an environmental impact of metal ions separation processes [12][13][14]. New, more efficient extractants and their extraction mechanisms [15,16] are being studied as well.…”

Section: Introductionmentioning

confidence: 99%

Implementation of the extraction method for the separation of Fe³+ and Ni²+ ions on cascade of mixing-settling extractors

Milevskii

Klychevskikh

Solov’ev

et al. 2022

Extraction processes are one of the most efficient methods of purification and separation of compounds. However, laboratory-developed methods commonly are not a complete technique that can be applied to the real manufacturing process with its extraction equipment. The extraction method for the separation of Fe3+ and Ni2+ ions using hydrochloric acid solution on a cascade of mixing-settling extractors has been determined. The extraction scheme chosen provides high efficiency of a cascade by using liquid pseudomembranes (LPM). Besides its extraction scheme simplicity, the LPM method is more economically beneficial compared to classical extraction methods. The process includes stages of Fe3+ ions extraction into the feed, followed by reextraction into the water and the feed purification for reusing it later on. The consumption of solvents and the stirring speed for the stable and efficient cascade work have been optimized. The described process is a complete technological solution for recycling processed battery waste.