Extraction of alkali metals into nitrobenzene in the presence of univalent polyhedral borate anions

Rais, J.; Selucký, P.; Kyrš, M.

doi:10.1016/0022-1902(76)80156-x

Cited by 162 publications

(51 citation statements)

References 6 publications

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“…With regard to the results of previous papers [6,7], the twophase water-Pb(NO 3 ) 2 -nitrobenzene-Sr(DCC) 2 extraction system can be described by the following equilibrium…”

Section: Resultsmentioning

confidence: 99%

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Extraction of lead with nitrobenzene solution of strontium dicarbollylcobaltate in the presence of 18-crown-6

Makrlík¹,

Vaňura

Bečková

1999

J. prakt. Chem.

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The observation that macrocyclic polyethers form stable complexes with alkali and alkaline earth metal cations has stimulated a great deal of interest in these crown compounds for their possible applications in various branches of chemistry and biology [1,2]. Extensive thermodynamic data [3,4] suggest that the stability of macrocyclic complexes depends on the relative cation and ligand cavity size, the number and spacial arrangements of the ligand bonding sites, the substitution on the macrocyclic ring and the solvent effects.The cyclic polyether 18-crown-6 has six oxygen atoms in the polyether ring, that are bond places of this ionophore [1,5].The aim of the present communication was to determine especially the stability constant of the complex species PbL 2+ , where L is 18-crown-6, in nitrobenzene saturated with water. Experimental18-crown-6 was supplied by Merck, Darmstadt, Germany. Cesium dicarbollylcobaltate (CsDCC) was synthesized in the Institute of Inorganic Chemistry, ®eþ, Czech Republic. The radionuclide 85 Sr (DuPont, Belgium) was of standard radiochemical purity. Nitrobenzene and all other chemicals (analytical grade, Lachema, Brno, Czech Republic) were used without further purification.In order to obtain the solution of HDCC in nitrobenzene, the solution of CsDCC in this medium (0.2 mol dm -3 ) was twice equilibrated with equal volumes of 15% (v/v) n-propanol in diluted H 2 SO 4 of the concentration of about 1 mol dm -3 . H 2 SO 4 and n-propanol were removed from the organic phase by a ten-fold equilibration with the solution of H 2 SO 4 PbL 2+ (nb) + Sr 2+ (aq) taking place in the two -phase water -nitrobenzene system (L = 18-crownin distilled water (about 1 mol dm -3 ) of an equal volume, followed by two equilibrations with distilled water. The concentration of HDCC in the nitrobenzene solution was determined by neutralization titration (NaOH, bromocresol green) after a ten-fold dilution with ethanol or acetone. The equilibration of the nitrobenzene solution of HDCC with stoichiometric Sr(OH) 2 , which was dissolved in the aqueous solution of Sr(NO 3 ) 2 (0.2 mol dm -3 ), yields the corresponding Sr(DCC) 2 solution in nitrobenzene.The extraction experiments were carried out in 10 cm 3 glass test-tubes fitted with polyethylene stoppers.2 cm 3 of the aqueous solution of Pb(NO 3 ) 2 of the concentration in the range from 2×10 -4 to 2 × 10 -3 mol dm -3 and microamounts of 85 Sr were added to 2 cm 3 of the nitrobenzene solution of 18-crown-6 and Sr(DCC) 2 , whose initial concentrations varied from 1× 10 -4 to 1× 10 -3 mol dm -3 (in all experiments, the initial concentration of 18-crown-6 in nitrobenzene, C L in,nb , was always equal to the initial concentration of Sr(DCC) 2 in this medium, C Sr(DCC) in,nb 2 ). The test-tubes filled with the solutions were shaken for two hours at a temperature of 25 ± 2 °C using a laboratory shaker; under these conditions the equilibrium in the system under study has been established already after approximately 20 minutes of shaking. Then the phases were separated by ce...

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“…With regard to the results of previous papers [6,7], the twophase water-Pb(NO 3 ) 2 -nitrobenzene-Sr(DCC) 2 extraction system can be described by the following equilibrium…”

Section: Resultsmentioning

confidence: 99%

“…With respect to previous papers [7,10], the two-phase water-Pb(NO 3 ) 2 -nitrobenzene-L-Sr(DCC) 2 (L = 18-crown-6) extraction system (see Experimental section), chosen for determination of stability of the complex PbL 2+ in water-saturated nitrobenzene, can be characterized by the main chemical equilibrium …”

Section: Resultsmentioning

confidence: 99%

Extraction of lead with nitrobenzene solution of strontium dicarbollylcobaltate in the presence of 18-crown-6

Makrlík¹,

Vaňura

Bečková

1999

J. prakt. Chem.

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“…The usefulness of CCD as caesium extractant was first identified by Rais and Kyrs in 1976 at the Nuclear Research Institute of Czechoslovakia [15] .They also identified that adding PEG to CCD dissolved in nitrobenzene would also allow extraction of strontium. Researchers of Khlopin Radium Institute (KRI) Russia developed a method for combined extraction of Cs/Sr, which was later applied on an industrial scale.…”

Section: Using Chlorinated Cobalt Dicarbollide (Ccd)/peg (Polyethylenmentioning

confidence: 99%

Treatment of Spent Nuclear Fuel for Separation, Immobilization and Disposal of Heat Generating High Level Fission Products, Caesium and Strontium

Aziz¹,

Ahsan²,

Khan

et al. 2017

J Chem Engg

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Separation of heat generating, high level fission product caesium and strontium from spent nuclear fuel boosts the capacity of waste repositories by as much as fifty times. For efficient use of already scarce repositories, separation of such fission products is mandatory. Separations of caesium and strontium using Chlorinated Cobalt Dicarbollide (CCD), PEG (Polyethylene Glycol), UNEX process and by Calixarenes or Fission Product Extraction Process (FPEX) were discussed. The UNEX method was then proposed as the most feasible method option. Following separation, nuclear waste immobilization techniques for such high-level fission product were discussed. The techniques included usage of concrete, glass and synthetic rock. Among them synthetic rock was identified as the most suitable one for immobilization of high-level nuclear waste. Finally, a safe disposal system with necessary required geology was shown for safe disposal of the waste.

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“…Rais and Kyrs, and their colleagues at the Nuclear Research Institute in Czechoslovakia, first published the utility of cobalt dicarbollide as a cesium extractant [37]. The Czech researchers determined that strontium could also be extracted with the cesium by adding polyethylene glycol (PEG) to the cobalt dicarbollide dissolved in nitrobenzene [38].…”

Section: Ccd (Chlorinated Cobalt Dicarbollide)/ Peg (Polyethylene Glymentioning

confidence: 99%

“…Because the very hydrophobic salts of cobalt dicarbollide are completely dissociated in the organic phase, polar aromatic or aliphatic nitrocompound diluents have typically been used in these extraction systems [37]. Although industrial-scale success was demonstrated with first generation nitrobenzene-based solvents at Russia's Mayak facility, in the United States the nitrobenzene and nitroaromatic diluents have been deemed unacceptable due to environmental, health, and plant safety issues.…”

Section: Ccd (Chlorinated Cobalt Dicarbollide)/ Peg (Polyethylene Glymentioning

confidence: 99%

Cesium and Strontium Separation Technologies Literature Review

Todd¹,

Law²,

Herbst³

2004

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Extraction of alkali metals into nitrobenzene in the presence of univalent polyhedral borate anions

Cited by 162 publications

References 6 publications

Extraction of lead with nitrobenzene solution of strontium dicarbollylcobaltate in the presence of 18-crown-6

Extraction of lead with nitrobenzene solution of strontium dicarbollylcobaltate in the presence of 18-crown-6

Treatment of Spent Nuclear Fuel for Separation, Immobilization and Disposal of Heat Generating High Level Fission Products, Caesium and Strontium

Cesium and Strontium Separation Technologies Literature Review

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