[en] The new method of barium and strontium separation is based on the extraction or re-extraction of the liquid mixture in a two-phase system in the presence of a polyoxonium compound. The best composition of the organic phase is a sodium alt of bis-1,2-dicarbolyl cobalt titanium solution in nitrobenzene and polyethylene glycol with a relative molecular weight of 300 to 500. The aqueous phase contains 1,2-cyclohexyldiaminetetraacetic acid or its salts. By suitable choice of pH of the aqueous phase within 7.5 and 9 it is possible to attain 99% conversion of strontium into the aqueous phase and 99% of barium into the organic phase. The advantage of the separation method is that it need not be repeated several times and yet a high separation factor may be achieved. (E.S.)

[en] The method which has been claimed for patenting is the separation of strontium and calcium based on the extraction or re-extraction of a liquid mixture in a two-phase system in the presence of polyoxonium compound. The organic phase consists of a solution of the sodium salt of bi-1,2-dicarbolyl cobalt titanium in nitrobenzene, possibly diluted with carbon tetrachloride, and polyethylene glycol with a relative molecular weight of 300 to 500. The aqueous phase consists of a solution of ethylenediaminetetraacetic acid. By suitable choice of pH of the aqueous phase within the range of 3.5 to 5 the conversion may be achieved of 99% strontium into organic phase and 99% calcium into the aqueous phase. The advantage of the said method is the high separation factor. (E.S.)

[en] Extraction takes place in a system consisting minimally of two phases - aqueous and nonaqueous. The system contains water, a nonaqueous solvent and minimally three more components. Suitable solvents include nitrobenzene, nitrotoluene, dichloroethane, dichloromethane, or other solvents. Other components of the system include an extraction reagent at least partly dissociated in the nonaqueous solvent used, a polyoxonium compound which forms a complex with at least one of the separated metals dissoluble in the used nonaqueous phase. The last component of the system is aminopolycarboxylic acid or its salt, or polycarboxylic acid with at least one aromatic or alicyclic saturated or nonsaturated ring containing at least one nitrogen atom. The most suitable separation procedure is extraction with a solution of sodium bis-1,2-dicarbolylcobalt-titanate or its derivative in nitrobenzene or nitrotoluene from the aqueous phase, consisting of ethylenediaminetetraacetic acid (EDTA) or its derivatives and homologues. The extraction takes place in the presence of polyethyleneglycol of a relative molecular weight of 300 to 500. The separation of alkali earth metals may be carried out as extraction and as re-extraction. The total extraction procedure does not depend on whether the separated metals are initially present in the aqueous or organic phase. An example is presented of the use of the patented separation procedure for separating trace amounts of radionuclides Cs⁺, Ca²⁺, Sr²⁺, Ba²⁺, Zr²⁺, CO²⁺ and Ce³⁺ from the aqueous phase. (E.S.)

[en] A chain reaction could result in case of the exceedance of the critical concentration of spontaneously fissionable compounds. It is therefore suggested that C₂B₁₀H₁₂ or neutral Ni(C₂B₉H₁₁)₂ i.e., substances effectively absorbing neutrons, be added to the organic phase during extraction. The organic phase may repeatedly be used for the extraction of other fractions of fissionable substances. (M.D.)

[en] A rapid extraction separation of Srsup(2+) from Casup(2+) with the nitrobenzene solution of sodium dicarbollylcobaltate (NaDCC) in the presence of polyethylene glycol with mean relative molecular weight of 400 (PEG 400) and tetrasodium salt of ethylenediamine-N,N,N',N'-tetraacetic acid (Nasub(4)L) was developed. The separation factor αsub(Sr/Ca) was approximately 10sup(4). (author)

[en] Extraction of Eu³⁺ microamounts from 0.1-0.4 M perchloric acid by the nitrobenzene solution of dicarbolide H⁺[Co(C₂B₉H₁₁)₂]^- in the presence of polyethylene glycols (average M_r=200, 300, 400) was studied. The equilibrium data and the typical maxima on the dependences of the metal distribution ratio on the total analytical concentration of polyethylene glycol in the system can be explained assuming that the species ML_org³⁺, ML_2org³⁺, ML_3org³⁺, MLH_-1org²⁺, and HL_org⁺ (where M³⁺=Eu³⁺, Ce³⁺; L=polyethylene glycol) are extracted into the organic phase. The values of extraction and equilibrium constants in the organic phase were determined and the effect of the polyethylene glycol molecular weight on the equilibrium constants and on the abundances of individual species in the organic phase is discussed. It was found that the addition of polyethylene glycol to the acid-nitrobenzene-dicarbolide system increased the values of the separation factors α_Ce/Eu. (author)

[en] In the two-phase water-nitrobenzene extraction system a method for gradual separation of Cssup(+) and Basup(2+) from the mixture of cations forming stable non-extractable complexes with ethylenediamine-N, N,sup(,)N'-tetraacetic acid in the presence of the sodium salt of dicarbollylcobaltate anion and polyethylene glycol ligand with a mean relative molecular mass of 400 (PEG 400), respectively, was developed. In the first extraction step Cssup(+) was extracted into the organic phase while the other cations studied (Casup(2+), Basup(2+), Srsup(2+), Znsup(2+), Cosup(2+), Cesup(3+)) remained in the aqueous phase. In the second extraction step Srsup(2+) and Basup(2+) were extracted into the nitrobenzene phase. Finally, in the following reextraction step Srsup(2+) was transferred into the aqueous phase while Basup(2+) remained in the organic phase. (author)

[en] A rapid extraction separation of Basup(2+) from Srsup(2+) with a nitrobenzene solution of sodium dicarbollylcobaltate (NaDCC) in the presence of polyethylene glycol with mean relative molecular weight of 400 (PEG 400) and tetrasodium salt of trans-cyclohexane-1,2-diamine-N,N,N,N',N'-tetraacetic acid (Nasub(4)L) was developed. The separation factor αsub(Ba/Sr) was approximately 10sup(4). (author)

[en] From extraction measurements, the individual extraction constant of the hexamminecobalt (III) cation, [Co(NH₃)₆]³⁺, in water nitrobenzene system has been determined (log Kⁱ_[Co(NH3)6]³⁺ -10.5). Further, using known thermodynamic parameters and general relation, the stability constant of the complex [Co(NH₃)₆]³⁺ in nitrobenzene saturated with water was evaluated for 25 deg C in the form log β_nb[Co(NH₃)₆]³⁺ = 54.1. (author). 13 refs

[en] Extraction of microamounts of barium by a nitrobenzene solution of ammonium dicarbollylcobaltate (NH₄⁺B^-) in the presence of 15-crown-5(15C5,L) has been investigated. The equilibrium data have been explained assuming that the complexes NH₄L⁺, NH₄L₂⁺ and BaL₂²⁺ are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. (author)