Neutral Organophosphorus Extractants Research Articles

Scandium Recovery Methods from Mining, Metallurgical Extractive Industries, and Industrial Wastes.

The recovery of scandium (Sc) from wastes and various resources using solvent extraction (SX) was discussed in detail. Moreover, the metallurgical extractive procedures for Sc recovery were presented. Acidic and neutral organophosphorus (OPCs) extractants are the most extensively used in industrial activities, considering that they provide the highest extraction efficiency of any of the valuable components. Due to the chemical and physical similarities of the rare earth metals, the separation and purification processes of Sc are difficult tasks. Sc has also been extracted from acidic solutions using carboxylic acids, amines, and acidic β-diketone, among other solvents and chemicals. For improving the extraction efficiencies, the development of mixed extractants or synergistic systems for the SX of Sc has been carried out in recent years. Different operational parameters play an important role in the extraction process, such as the type of the aqueous phase and its acidity, the aqueous (A) to organic (O) and solid (S) to liquid (L) phase ratios, as well as the type of the diluents. Sc recovery is now implemented in industrial production using a combination of hydrometallurgical and pyrometallurgical techniques, such as ore pre-treatment, leaching, SX, precipitation, and calcination. The hydrometallurgical methods (acid leaching and SX) were effective for Sc recovery. Furthermore, the OPCs bis(2-ethylhexyl) phosphoric acid (D2EHPA/P204) and tributyl phosphate (TBP) showed interesting potential taking into consideration some co-extracted metals such as Fe(III) and Ti(IV).

Structural effects of neutral organophosphorus extractants on solvent extraction of rare-earth elements from aqueous and non-aqueous nitrate solutions

A series of neutral organophosphorus extractants, comprising phosphine oxides, phosphinates, phosphonates and phosphates with linear and branched alkyl chains have been synthesized. Together with some similar commercial extractants, the performance of these new compounds in the extraction of Nd(III) and Dy(III) from both aqueous nitrate and non-aqueous ethylene glycol nitrate solutions was investigated. It was observed that: (1) the order of extraction efficiency of the rare-earth elements is the same as the basicity (electronegativity) of the extractant molecules: phosphine oxide > phosphinate > phosphonate > phosphate; (2) the same type of extractants with longer alkyl chains show higher metal extraction efficiencies, and branched chains hamper the extraction; (3) extraction from ethylene glycol solutions give higher separation factors for all types of neutral organophosphorus extractants than the corresponding aqueous solutions; and finally (4) phosphinates and phosphonates are more promising extractants than phosphine oxides and phosphates for separation of Nd(III) and Dy(III) by solvent extraction from ethylene glycol solutions. These results are useful for the development of more efficient and more selective new extractants and separation processes.

Separation of thorium from rare earths with high-performance diphenyl phosphate extractant

In this article, some novel extractants were synthesized for the separation of Th and rare earth (RE). Among the synthesized neutral organophosphorus extractants, n-octyl phosphate diphenyl (ODP) revealed excellent extraction efficiencies and selectivities for Th(IV). Moreover, loading capacity of ODP for Th(IV) (0.015mol/L) reached 130mg/L, the loading capacities and speed were higher and faster than those of P507, TBP and C272, respectively. Furthermore, the loaded Th(IV) could be fully stripped by sulfuric acid and hydrochloric acid. The novel extractant ODP has been indicated to be an efficient extractant for the separation of Th, REs and Fe from ion-adsorption type RE minerals, which reveals significances in the fields of resource, environment and energy.

Selective extraction and separation of Ce(IV) from thorium and trivalent rare earths in sulfate medium by an α-aminophosphonate extractant

A novel extractant, di (2-ethylhexyl) (2-((2-ethylhexyl) amino) propan-2-yl) phosphonate (DEHAPP, abbreviated as B), was synthesized for the selective extraction of Ce(IV) in sulfate medium. The effect of contact time, the H2SO4 concentration, the DEHAPP concentration and temperature on the Ce(IV) extraction were studied systematically. DEHAPP exhibits a good extraction ability towards Ce(IV) when compared with other neutral organophosphorus extractants such as Cyanex 923, Cyanex 925 and DEHEHP. The extraction equilibrium constants and thermodynamic parameters (ΔG, ΔH and ΔS) were calculated. The extraction reaction of Ce(IV) is an endothermic process. The extracted complexes were determined to be H2SO4·B(org) and Ce(HSO4)2SO4·2B(org). A extraction process to selectively recover Ce(IV) from bastnaesite leaching was proposed, by which the purity of cerium product reached 99.5% with a yield of 90.7%.

A phosphorylated ketone, 5-(diphenylphosphoryl)hexan-3-one, as a new effective extractant for the recovery and separation of lanthanides in the eudialyte processing

The increased consumption of rare earth elements (REEs) requires processing of new lowprofitable mineral raw materials such as ores with low REE con� tents and industrygenerated wastes of various origin (chemical plant wastes, spent nuclear fuel and so on). Eudialyte containing up to 2.5% lanthanide impurities is a highly promising "nontraditional" mineral for the recovery of lanthanides (1). The elemental composi� tion of lanthanides in eudialyte is characterized by high (up to 50% of the lanthanide sum) contents of heavy lanthanides, which makes eudialyte a valuable mineral raw material for the recovery of rare earth elements. This distinguishes eudialyte from other known minerals such as apatite or loparite, in which the content of most expensive yttrium group lan� thanides is much lower (2). Eudialyte is readily digested with acids without preliminary activation, which markedly facilitates the industrial processing of the mineral (3). Since eudialyte contains consider� able amounts of some other valuable components (zirconium, scandium), apart from lanthanides, a topical task is to develop an integrated processing technology for this mineral. The traditional ore processing flow charts include leaching with concentrated mineral acids and recovery of rare earth elements by multistep liquid extraction (3-6). In the processing of raw materials with low contents of valuable components (eudialyte, apatite, or fluoroapatite ores), it is especially important to choose an appropriate extractant, because the known neutral organophosphorus extractants (NOPCs) have rather low distribution ratios and separation levels for lanthanides and extract actinides at almost the same level. Therefore, the search for new effective, synthet� ically accessible, and commercially attractive extract� ants for the recovery and separation of rare earth ele� ments remains topical.

Extraction of lead, copper, and bismuth with mixtures of N,N-di(1-methylheptyl) acetamide and neutral organophosphorus extractants

In the present work, the extraction of lead, copper, and bismuth with N,N-di(1-methylheptyl) acetamide (N503) and its mixtures with neutral organophosphorus extractants, tri-butyl-phosphate (TBP), 2-ethylhexyl phosphonic acid di-2-ethyl ester (EHDEHP), and aliphatic trialkyl phosphine oxide (Cyanex923), was studied. Whether the mixtures had synergistic or antagonistic effect were investigated and considered for the separation of bismuth, lead, and copper. The synergistic extraction stoichiometries were studied in detail by the methods of slope and constant mole, with the extraction of lead with N503+DEHEHP as a representative. Effects of temperature on the extraction were also determined to investigate the thermodynamic parameters.

Synergistic Effect in the Solvent Extraction and Separation of Lanthanoids by 4-(4-Fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one in the Presence of Monofunctional Neutral Organophosphorus Extractants

4-(4-Fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one (HL) has been synthesized and its complexation properties in solution were examined. Mixed ligand chelate extraction of trivalent lanthanoids (La, Nd, Eu, Ho, and Lu) from chloride medium at constant ionic strength μ = 0.1 into C6H6 with HL in combination with one of the three phosphine oxide compounds trioctylphosphine oxide (TOPO), tributylphosphine oxide (TBPO), or triphenylphosphine oxide (TPPO) as well as with tributylphosphate (TBP) was studied. The interaction between the extractants in C6H6-d6 has been studied by 1H, 13C, and 31P NMR spectroscopy and its influence on the synergistic extraction of Nd(III) ion has been investigated. The composition of the extracted species was established as LnL3·HL with HL alone and as LnL3·2S in the presence of TOPO, TPPO, and TBP or LnL3·S with the mixture of HL–TBPO. A synergic effect up to 106 was observed for the extraction of the above-mentioned lanthanoid ions with binary mixtures of extractants. The change of the synergistic agent causes a significant increase of the KL,S values. The parameters of the extraction process were determined and the separation factors were calculated.

Extraction Mechanism of Rare Earths with Bifuncional Ionic Liquids (Bif-ILs) [A336][CA-12]/[A336][CA-100] in Nitrate Medium

Abstract In this study, solvent extraction of rare earths with bifuncional ionic liquids (Bif-ILs) [A336][CA-12]/[A336][CA-100] was systematically investigated in nitate medium. The extraction abilities for rare earths were compared with those of organic carboxylic acids CA-12/CA-100 and neutral organophosphorus extractants TBP/P350, and they are in the descending order: [A336][CA-12]/[A336][CA-100]>CA-12/CA-100>P350>TBP. The slope analysis method was used to determine the extraction stoichiometry. The study of extraction mechanisms of rare earths by Bif-ILs [A336][CA-12]/[A336][CA-100] showed that the mechanism is in accord with complexing mechanism. By studying the effect of extraction equilibration time and temperature on the extraction efficiencies, we found that the extraction process of rare earths by Bif-ILs [A336][CA-12]/[A336][CA-100] is a fast equilibrium and an exothermic reaction. The recycling and stripping experiments indicated Bif-ILs [A336][CA-12]/[A336][CA-100] with high stability and easy stripping characteristics are suitable for extracting rare earths.

Recovery of rare earth elements from simulated fluorescent powder using bifunctional ionic liquid extractants (Bif‐ILEs)

AbstractBACKGROUND:Numerous high purity ammonium‐type ionic liquid extractants have been prepared for engineering purposes. Bifunctional ionic liquid extractants (Bif‐ILEs) have been widely applied to separate and extract rare earths and metal ions with high extraction efficiencies and selectivities. In the present study, new Bif‐ILEs [A336][P204] and [A336][P507] have been used to extract rare earths from a simulated solution of a fluorescent powder in a high concentration of Al(NO3)3.RESULTS:Bif‐ILEs were prepared from Aliquat336 (A336) and the commercial organophosphorus acid extractants, P204 and P507. These extractants [A336][P204] and [A336][P507] have similar characteristics to neutral organophosphorus extractants. When these Bif‐ILEs were used to extract RE(III) from a simulated waste fluorescent powder system a third phase appeared which could be eliminated by the addition of 10% isopropanol modifier. The coexisting Al2O3in the fluorescent powder was changed to a salting‐out agent (Al(NO3)3) in the extraction process and promoted the extraction efficiency of RE(III). Using a countercurrent extraction process at a phase ratioVo:Vw= 4:1 and pH = 0.56, the RE(III) recovery reached 95.2% in 5–7 stages. Finally, the extractabilities of these bifunctional extractants were compared with the neutral organophosphorus extractants P350, TBP and Cyanex923 at different concentrations, initial pHs and temperatures.CONCLUSIONS:By comparison with other neutral organophosphorus extractants, Bif‐ILEs [A336][P204] and [A336][P507] can be considered efficient potential extractants for separating and recycling REEs and Al2O3from waste fluorescent powder. Copyright © 2011 Society of Chemical Industry

Liquid-liquid solvent extraction of rare earths from chloride medium with sec-nonylphenoxy acetic acid and its mixtures with neutral organophosphorus extractants

In the present study, sec-nonylphenoxy acetic acid (CA100) and its mixtures with four neutral organophosphorus extractants, tri-butyl-phosphate (TBP), 2-ethylhexyl phosphonic acid di-2-ethyl ester (DEHEHP), Cyanex923, and Cyanex925 have been applied to the extraction of rare earths. Results show that all the four mixing systems do not have evident synergistic effects on the extraction of rare earths. The different extraction effects have been considered to the separation of rare earths. The four mixtures may be applied to the separation of yttrium from some certain lanthanoids at proper mole fractions of CA100.

Solvent Extraction Studies of Zinc(II) and Cadmium(II) from a Chloride Medium with Mixtures of Neutral Organophosphorus Extractants and Amine Extractants

In the present study, the extraction of zinc(II) and cadmium(II) with mixtures of neutral organophosphorus extractants (aliphatic trialkyl phosphine oxide, Cyanex 923, or branched cyclic trialkyl phosphine oxide, Cyanex 925) and amine extractants (N,N-di(1-methylheptyl) acetamide, N503, or trialkyl amine, N235) has been investigated. Synergistic effects were observed for zinc(II) with Cyanex 923 + N503 and for cadmium(II) with Cyanex 923 + N235 and Cyanex 925 + N235. However, the other mixing systems do not have synergistic effects on zinc(II) and cadmium(II). According to the different extraction effects, the separation possibilities of zinc(II) and cadmium(II) are discussed. The extraction mechanisms have been studied with the methods of slope analysis and constant moles in the three synergistic systems. The extracted compounds, the equilibrium constants, and thermodynamic functions have also been determined.

A literature review of titanium solvent extraction in chloride media

A number of organic extractants for Ti(IV) solvent extraction from chloride solutions were reviewed, including acidic organophosphorus, neutral organophosphorus and amine extractants. The extraction of Ti(IV) by acidic organophosphorus extractants is via a cation exchange mechanism in low hydrochloric acid concentration solutions, whilst in high hydrochloric acid concentration solutions, it proceeds via a solvating mechanism. The Ti(IV) extraction kinetics with D2EHPA, EHPEHPA and Cyanex 272 is very slow: more than 1 h is required to reach equilibrium in some cases. The Ti(IV) extraction kinetics with Cyanex 301 and Cyanex 302 is fast: only 2–5 min are required to reach equilibrium. The Ti(IV) extraction kinetics with neutral organophosphorus extractants, such as TBP, TOPO and TRPO is also fast: the extraction equilibrium reaches within 5 min. The extraction mechanism with neutral organophosphorus extractants is solvating. Stripping Ti(IV) from loaded acidic organophosphorus extractants including D2EHPA, EHPEHPA, Cyanex 272, Cyanex301 and Cyanex 302 is difficult, requiring H 2SO 4 solution in the presence of H 2O 2. In contrast, the stripping of Ti(IV) from neutral organophosphorus extractants is much easier with low acidic solutions. It was found that the practical application of acidic organophosphorus extractants is difficult for Ti(IV) extraction from chloride solutions due to their slow extraction kinetics and difficulty in stripping, and neutral organophosphorus extractants could be used to separate both Fe(III) and Ti(IV) from other impurities or separate Fe(III) from Ti(IV) and all other impurities.

ChemInform Abstract: Complexes of Actinoid and Lanthanoid Elements with Neutral Organophosphorus Extractants

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Enhanced extraction and separation of zirconium(IV) and hafnium(IV) with 3-phenyl-4-benzoyl-5-isoxazolone in presence of various neutral organophosphorus extractants

Various 3-phenyl-4-aroyl-5-isoxazolones, namely, 3-phenyl-4-benzoyl-5-isoxazolone (HPBI), 3-phenyl-4-(4-fluorobenzoyl)-5-isoxazolone (HFBPI) and 3-phenyl-4-(4-toluoyl)-5-isoxazolone (HTPI) were synthesized and examined with regard to the solvent extraction behavior of Zr(IV) and Hf(IV) from hydrochloric acid solutions. The results demonstrated that Zr(IV) and Hf(IV) extracted into chloroform with 3-phenyl-4-aroyl-5-isoxazolones (HA), as ZrOA2 and HfOA2, respectively. The equilibrium constants of the extracted complexes follow an order HFBPI > HPBI > HTPI, which is in accordance with their pK a values. The synergistic extraction of Zr(IV) and Hf(IV) was also investigated with mixtures of HPBI and tri-n-octylphosphine oxide (TOPO), trialkylphosphine oxide (TRPO), and tri-n-butylphosphate (TBP), where the complexation strength follows the order TOPO > TRPO > TBP. The equilibrium constants of the synergistically extracted complexes have been correlated with the donor ability of phosphoryl oxygen of the neutral organophosphorus extractants in terms of their 31P NMR chemical shifts and their basicity values. The addition of neutral organophosphorus extractant to the metal chelate system not only enhances the extraction efficiency but also improves the selectivity between these metal ions.

Anomalous effects in extraction of lanthanides and actinides with bidentate neutral organophosphorus extractants. Role of proton hydrate solvates

Extraction of europium, lithium, and acids from nitric acid and perchloric acid media with solutions of bidentate neutral organophosphorus compounds (BNOPCs) in polar diluents (dichloroethane, meta-nitrobenzotrifluoride, and trifluoromethyl phenyl sulfone) was studied. It was found that cationic complexes of BNOPCs with proton hydrates or lithium cation are formed in the organic phase. BNOPC hydrate solvates H+ · nH2O · mBNOPC extract europium substantially better than do free BNOPCs. The main differences of BNOPCs from monodentate extractants are anomalous aryl effect (AAE) and perchlorate and synergic (the latter is observed in the presence of chlorinated cobalt dicarbollide) effects, which are connected with specific properties of proton hydrate solvates with BNOPC. The existence of BNOPC cationic complexes found by IR spectroscopy in polar diluents was confirmed by ESI-MS. The effect of preorganization of the extractant molecule and the change from the solvate mechanism of the metal ion extraction to the cation-exchange mechanism are apparently responsible for the high extraction ability of proton hydrate solvates with BNOPCs.

Synergistic Extraction of Zirconium(IV) and Hafnium(IV) with 4‐Acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones) in the Presence of Neutral Organophosphorus Extractants

Various 4‐acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones), namely, 4‐adipoylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) (H2AdBP), 4‐sebacoylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) (H2SbBP) and 4‐dodecandioylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) (H2DdBP) were synthesized and examined with regard to the solvent extraction behavior of zirconium(IV) and hafnium(IV) from hydrochloric acid solutions. The results demonstrate that Zr(IV) and Hf(IV) extracted into chloroform with 4‐acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones) (H2X), as ZrO(HX)2 and HfO(HX)2, respectively. The equilibrium constants (K ex) of the extracted complexes follow an order H2SbBP>H2AdBP>H2DdBP. The synergistic extraction of Zr(IV) and Hf(IV) was also investigated with mixtures of H2SbBP and tri‐n‐butylphosphate (TBP), tri‐n‐octylphosphine oxide (TOPO), and trialkylphosphine oxide (TRPO), where the complexation strength follows the order TOPO>TRPO>TBP. The equilibrium constants of the synergistically extracted complexes have been correlated with the donor ability of the phosphoryl oxygen of the neutral organophosphorus extractants in terms of their 31P NMR chemical shifts and their basicity values (KH =nitric acid uptake constant).

Effect of Polymethylene Chain Length of 4‐Acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones) on the Extraction of Vanadium(V): Synergistic Effect with Neutral Organophosphorus Extractants

Various 4‐acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones), namely, 4‐adipoylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) (H2AdBP), 4‐sebacoylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) (H2SbBP) and 4‐dodecandioylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) (H2DdBP) were synthesized and examined with regard to the solvent extraction behavior of vanadium(V) and other multivalent metal ions that are present in the waste chloride liquors of titanium mineral‐processing industry. The results demonstrate that vanadium(V) is selectively extracted into chloroform with 4‐acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones) as VO2(HX), where H2X refers to the 4‐acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolone) and K ex,V(V) denotes the equilibrium constant. On the other hand, magnesium(II), aluminum(III), titanium(IV), chromium(III), manganese(II), iron(II), and iron(III), were not found to be extracted into the organic phase. The K ex,V(V) values of various 4‐acylbispyrazolone derivatives follow the order H2SbBP>H2DdBP>H2AdBP. Solid complexes of vanadium(V) with various 4‐acylbis(1‐phenyl‐3‐methyl‐5‐pyrazolones) have been isolated and characterized by elemental analyses and IR spectral data to further clarify the nature of the extracted complexes. The synergistic effect on the addition of various neutral organophosphorus extractants to the metal‐chelate system has been investigated, revealing significant enhancement in the extraction efficiency of vanadium(V). The equilibrium constants of the synergistically extracted complexes have been correlated with the donor ability of the phosphoryl oxygen of the neutral organophosphorus extractants in terms of their 31P NMR chemical shifts and their basicity values (K H =nitric acid uptake constant). The potential of these reagents as extractants for the separation and recovery of vanadium(V) from the waste chloride liquors of the titanium mineral processing industry has also been assessed.

Steric effects of polymethylene chain of 4-acylbis(pyrazolones) on the solvent extraction of trivalent lanthanoids: synergistic effect with mono and bifunctional neutral organophosphorus extractants

Various 4-acylbis(pyrazolones), namely 4-adipoylbis(1-phenyl-3-methyl-5-pyrazolone) (H 2AdBP = 1), 4-suberoylbis(1-phenyl-3-methyl-5-pyrazolone) (H 2SuBP = 2), 4-sebacoylbis(1-phenyl-3-methyl-5-pyrazolone) (H 2SbBP = 3), 4-dodecandioylbis(1-phenyl-3-methyl-5-pyrazolone) (H 2DdBP = 4) have been synthesized and examined their solvent extraction behavior towards trivalent lanthanoids (Nd 3+, Eu 3+ and Tm 3+). The extraction of Ln 3+ ions was found to increase monotonically with increasing atomic number of these metal ions. 1– 4 reagents showed an initial increase in the extraction efficiency of Ln 3+ ion with increasing polymethylene chain length, (CH 2) n , from n = 4 to 8 and thereafter a decreasing trend, for n = 10. The equilibrium constants ( K ex) of the extracted complexes have been deduced by nonlinear regression analysis with the aid of suitable chemically based model developed by taking into account chemical mass action principles. The K ex values were correlated with the polymethylene chain length, by measuring the distance between the carbonyl oxygen atoms connected to the polymethylene chain with the help of semi-empirical PM3 molecular modelling calculations. The synergistic effect on the addition of various neutral organophosphorus extractants to the metal–chelate system has also been investigated. Not only enhanced extraction efficiency, but also improved selectivity has been observed among these Ln 3+ ions. The equilibrium constants of the synergistically extracted complexes have been correlated with the donor ability of the phosphoryl oxygen of the neutral organophosphorus extractants in terms of their 31P NMR chemical shifts and their basicity values ( K H = nitric acid uptake constant).

Enhanced extraction of thorium(IV) and uranium(VI) with 1-phenyl-3-methyl-4-pivaloyl-5-pyrazolone in the presence of various neutral organophosphorus extractants

Summary This paper describes the results of the investigations carried out on the extraction of thorium(IV) and uranium(VI) from dilute nitric acid solutions into chloroform with 1-phenyl-3-methyl-4-pivaloyl-5-pyrazolone (HPMPP) in the presence and absence of various neutral organophosphorus extractants, tributylphosphate (TBP), octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and trioctylphosphine oxide (TOPO). The results demonstrated that these metal ions were extracted into chloroform as Th(PMPP)4 and UO2(PMPP)2 with HPMPP alone and as Th(PMPP)4·S and UO2(PMPP)2·S in the presence of neutral organophosphorus extractants (S). High selectivity (S.F.=2.8×105) has been observed between thorium(IV) and uranium(VI) when extracted with HPMPP alone. The equilibrium constants of the extracted complexes have been deduced by non-linear regression analysis. The equilibrium constants of the synergistically extracted complexes have been correlated with the donor ability of the phosphoryl oxygen of the neutral organophosphorus extractants in terms of their 31P NMR chemical shifts and basicity values (K H = nitric acid uptake constant). The addition of a neutral organophosphorus extractant to the metal chelate system significantly enhances the extraction efficiency of these metal ions. Thorium(IV) and uranium(VI) complexes of HPMPP and mixtures of HPMPP and neutral organophosphorus extractants were synthesized and characterized by IR spectral data to further clarify the nature of the extracted complexes.

Scintillators Based on Ytterbium Chloride Adducts with Neutral Organophosphorus Extractants for Detecting Solar Neutrino for LENS (Low-Energy Neutrino Spectroscopy) Experiment

The main features of extraction of ytterbium chloride with dibutyl butylphosphonate (DBBP) and triisoamylphosphine oxide (TIAPO) were studied. The effects of temperature, DBBP and TIAPO concentrations in 1,2,4-trimethylbenzene (TMB), and concentrations of salting-out agents LiCl and NH4Cl and mineral acid (HCl) on the ytterbium distribution coefficient were determined. The isotherms of extraction of HCl and YbCl3 with 50% DBBP and TIAPO in TMB were obtained. The composition of the extractable complexes of ytterbium chloride with DBBP and TIAPO (S), YbCl3·3S, was determined by saturation and dilution methods. The saturation of 50% solutions of DBBP and TIAPO in TMB with ytterbium chloride was modeled. Two samples of scintillators with ytterbium concentration of 90 g l- 1 were prepared, and their physical parameters were measured. The stability of sample properties was tested for 18 months.