Extraction behavior of trivalent lanthanoids and yttrium with bis (2,4,4-trimethylpentyl)octylphosphine oxide

The extraction behavior of yttrium and trivalent lanthanoids has been investigated from thiocyanate solutions using bis(2,4,4-trimethylpentyl)octylphosphine oxide (CYANEX 925) in xylene as an extractant by tracer techniques. The results demonstrate that these trivalent metal ions are extracted as M(SCN)₃•3CYANEX 925. The equalibrium constants of the extracted complexes have been deduced by non-linear regression analysis. The extraction behavior of trivalent lanthanoids and yttrium was found to be ambiguous since the distribution ratios of these metal ions are nonmonotinic function of atomic number (La<Y<Pm<Tm<Ho<Eu<Yb<Lu). The separation factors between these trivalent metal ions have been calculated and compared with commercially important extraction systems like tributylphosphate (TBP), trioctylphosphine oxide (TOPO), octy(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and di-2-ethylhexyl phosphoric acid (DEHPA). The possibilities for separating yttrium from trivalent lanthanoids has also been discussed.     

Extraction of cobalt (II) and nickel (II) by a solvent impregnated resin containing bis(2,4,4-trimethylpentyl)monothiophosphinic acid

In the present work, studies have been conducted on the equilibrium distribution of cobalt (II) and nickel (II) between aqueous hydrochloric solution and macromolecular resin impregnated with bis(2,4,4-trimethylpentyl)monothiophosphinic acid (Cyanex302, HL). Effects of extraction time, pH values, metal ion concentration, and temperature were investigated. Analysis of the results shows that the extraction of the two metal ions can be explained assuming the formation of metal complexes in the resin phase with a general composition ML ₂. An extraction reaction is proposed and the equilibrium constants of the complexes were determined. The Freundlich isotherm and thermodynamic quantities, i.e., ΔG, ΔH and ΔS were also obtained. Both of the extraction reactions of cobalt (II) and nickel (II) are endothermic ones. The efficiency of the resin in the separation of cobalt (II) and nickel (II) is provided according to the separation factors. Under the experimental conditions employed, pH₅₀ values for cobalt (II) and nickel (II) are 3.76, 5.01, respectively. The logarithmic value of separation factor was calculated as 2.50.     

Solvent extraction of rare-earth metals with bis(2-ethylhexyl)phosphinic acid

 The extraction behavior of tervalent rare-earth metals (Ln) using a heptane solution containing bis(2-ethylhexyl)phosphinic acid (PIA-8, HR) from 0.1 mol/dm³ sodium perchlorate media was studied. The pH_0.5 values and separation factors obtained were compared among the metals. The stoichiometry of the extracted species and the extraction constants for the present aqueous/heptane system were determined by slope analysis. It is demonstrated that the rare-earth metals were extracted as monomers LnR₃⋅mHR (m=3, 4, 5 or 6), and the extracted species could be stripped into a relatively low concentrated hydrochloric acid. PIA-8 was found to be the most selective extractant for the mutual separation of rare-earth metals among the other phosphinic acids reported. Received: 27 February 1996/Revised: 13 May 1996/Accepted: 21 May 1996     

Cadmium(II) extraction from phosphoric media by bis(2,4,4-trimethylpentyl) thiophosphinic acid (Cyanex 302)

Cadmium extraction from phosphoric acid at different concentrations (0.7–8.8 M) by the commercial reagent Cyanex 302 in kerosene has been studied. Experimental results have been treated graphically and numerically and the formation of the species CdR₂(HR) in the organic phase has been proposed. The value of the equilibrium constant increases with the phosphoric concentration in the aqueous media. Small Cyanex 302 concentrations in the organic phase are enough to remove Cd(II) quantitatively from phosphoric acid solutions.     

二（2,4,4—三甲基戊基）膦酸萃取Er（Ⅲ）的动力学

用新型恒界面池法首次研究了二（２，４，４－三甲基戊基）膦酸在盐酸介质中萃取Ｅｒ（Ⅲ）的动力学，测定了流体线性流速、有机相浓度、水相浓度和酸度、温度及界面面积等因素对萃取速率的影响，提出其速率方程，求出萃取反应的活化能，并对萃取反应机理进行了探讨．     

On the interaction of metal extractant reagents. Investigation of the aggregation ofdi(2,4,4-trimethylpentyl)phosphinic acid anddi(n-octyl)phosphinic acid in toluene by vapour-pressure osmometry

Summary The aggregation equilibria ofdi(2,4,4-trimethylpentyl)phosphinic acid (HDTMPP) anddi(n-octyl)phosphinic acid (HDOP) dissolved in toluene have been investigated by vapour-pressure osmometry (VPO) at different temperatures. The experimental data have been treated both graphically and numerically, and the average aggregation numberñ as well as the aggregation constant have been determined. The results suggest that dimers are formed and that the dimerization constant decreases with temperature. Finally, the enthalpies for the aggregation ofdi(2,4,4-trimethylpentyl)phosphinic acid anddi(n-octyl)phosphinic acid in toluene have been estimated using thevan't Hoff equation.

---

Über die Wechselwirkung metallextrahierender Reagentien. Untersuchung der Aggregation vondi-(2,2,4-Trimethylpentyl)-phosphinsäure unddi-(n-Octyl)-phosphinsäure in Toluol mittels Dampfdruckosmometrie

Zusammenfassung Die Aggregationsgleichgewichte von in Toluol gelösterdi-(2,4,4-Trimethylphentyl)-phosphinsäure (HDTMPP) unddi-(n-Octyl)-phosphinsäure (HDOP) wurden mittels Dampfdruckosmometrie (VPO) bei verschiedenen Temperaturen untersucht. Die experimentellen Daten wurden sowohl graphisch als auch numerisch ausgewertet; es wurden sowohl die mittlere Aggregationszahlñ als auch die Aggregationskonstante bestimmt. Die Resultate lassen vermuten, daß Dimere gebildet werden und die Dimerisationskonstante mit der Temperatur abnimmt. Mit Hilfe dervan't Hoffschen Gleichung wurden die Enthalpien der Aggregation vondi-(2,4,4-Trimethylpentyl)-phosphinsäure unddi-(n-Octyl)-phosphinsäure in Toluol abgeschätzt.

     

Extraction of trivalent lanthanide cations by diphenyl phosphinic acid

The distribution of trivalent lanthanides between solutions of diphenyl phosphinic acid, (ϕ)₂PO(OH), in chloroform and aqueous phases containing nitrate ions was investigated radiometrically. The distribution ratio was studied as a function of mineral acid and salt concentrations in the aqueous phase and extractant concentration in the organic phase, for all lanthanides except Pm. The compositions of the extracted complexes were investigated by the usual slope analysis. The results obtained for a given set of conditions indicate that none of the anions present in the aqueous medium are present in the extracted complex species. For these conditions, the distribution ratio D was found to vary as [extractant]^2.7 and [H⁺]⁻³, where the concentrations refer to the organic and aqueous phases, respectively. It therefore appears that a mixture of complex species is extracted, and the possible structures of these species and a mechanism for the extraction are discussed.     

Liquid-liquid extraction and reversed phase chromatographic behaviour of some 3d metal ions using bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301)

Studies have been carried out on the extraction behavior of some metal ions of the first transition series using bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301) from mineral acid media. The effect of various parameters influencing the extraction such as the nature of the diluent, concentration of the acid and the extractant on the distribution has been investigated. Based on the distribution data some binary separations have been proposed. A flow sheet of a scheme is given for the recovery of manganese free cobalt from a spent catalyst used in the manufacture of poly(ethyleneterepthalate).     

Extraction equilibria of some transition metal ions by bis(2-ethylhexyl)phosphinic acid

Measurements of dimerization constants (K(d,HR)) and distribution constants (K(D,HR)) of bis(2-ethylhexyl)phosphinic acid (PIA-8) in three kinds of organic diluents were carried out by a potentiometric two-phase titration technique at 298 +/- 0.1 K. Extraction of iron(III), zinc(II), copper(II), manganese(II), cadmium(II), cobalt(II) and nickel(II) by PIA-8 from 1.0 mol dm(-3) ammonium sulfate solution into heptane was investigated as a function of pH and extractant concentration. The data have been analyzed both graphically and numerically to determine the stoichiometry of extracted species and their extraction constants. The extracted metal species were found to be FeR(3) . 2HR for iron(III), ZnR(2) and ZnR(2) . 3HR for zinc(II), CuR(2) . HR and CuR(2) . 5HR for copper(II), MnR(2) . 2HR and MnR(2) . 3HR for manganese(II), CdR(2) . 3HR for cadmium(II), CoR(2) . HR and CoR(2) . 4HR for cobalt(II) and NiR(2) . 3HR and NiR(2) . 6HR for nickel(II), respectively.     

A novel method for the separation of bis(alpha-hydroxyalkyl)phosphinic acid diastereoisomers via formation of novel cyclic phosphinic acids

The reaction of aromatic and aliphatic aldehydes with hypophosphorus acid under microwave irradiation was examined. The reaction gave a mixture of a racemic pair of bis(alpha-hydroxyalkyl)phosphinic acids and acetal derivatives from the corresponding bis(alpha-hydroxyalkyl)phosphinic acids of meso-stereochemistry in good yield. The difference in solubility in organic solvents due to polarity allowed us to readily separate these compounds. This method constitutes an easy, rapid, and good-yielding preparation and separation of bis(alpha-hydroxyalkyl) phosphinic acid diastereoisomers from simple starting materials using microwave irradiation.     

二（2,4,4—三甲基戊基）膦酸从盐酸介质中萃取钍（Ⅳ）的机理

研究了二（２，４，４－三甲基戊基）膦酸的正辛烷溶液从盐酸介质中萃取钍的机理。在未控制离子强度下，萃取平衡反应为：Ｔｈ＾４＋＋Ｃｌ＾－＋３（ＨＡ）２（ｏ）→ＴｈＣｌＡ３（ＨＡ）３（ｏ）＋３Ｈ＾＋。在控制离子强度为１．０ｍｏｌ／Ｌ时，萃取反应为Ｔｈ＾４＋＋２Ｃｌ＾－＋３（ＨＡ）２（Ｏ）→ＴｈＣｌ２Ａ２．（ＨＡ）４（Ｐ）＋２Ｈ＾＋。用饮和法确定的萃合物组成为ＴｈＣｌＡ３．计算了萃取反应的平衡常数及热力学     

二-(2,4,4-三甲基戊基)膦酸浸渍树脂分离Tb~(3 ),Dy~(3 ),Ho~(3 ),Er~(3 )的研究

研究了大孔网状树脂XAD 4 ,XAD 7,XAD 1 1 80对二 -( 2 ,4 ,4 三甲基戊基 )膦酸 (Cyanex 571 )浸渍树脂的吸附及制备方法 ,并对Cyanex571浸渍树脂分离稀土的性能进行了研究 ,发现在盐酸介质中Cyanex 571 /XAD 7具有最强的萃取能力 ,树脂中的萃取剂含量在 0 35～ 0 4 5g·g- 1时 ,其萃取性能最好。将上述浸渍树脂装入色层柱对稀土元素 (Tb3 ,Dy3 ,Ho3 ,Er3 )进行了分离 ,且降低负载量和流速分离效果更好。     

Extraction chromatography with bis(2-ethylhexyl)phosphoric acid for separation of tin(IV)

Tin is extracted from 0.01M hydrochloric acid on a silica-gel column impregnated with bis(2-ethylhexyl)phosphoric acid, stripped with 5M hydrochloric acid, and then determined spectrophotometrically as its Pyrocatechol Violet complex at 555 nm. Tin has been separated from several multicomponent mixtures containing arsenic, antimony, bismuth, lead and copper, and determined in various alloys.     

二(2,4,4-三甲基戊基)膦酸在中空纤维膜器中萃取镱、铒及传质研究

中空纤维膜萃取技术是将液液萃取过程与膜过程相结合的新型分离技术．二（２,４,４三甲基戊基）膦酸（ＨＢＴＭＰＰ,ＨＬ）萃取稀土及其它高价金属离子时所需水相酸度低,反萃容易,加之空间位阻等因素,很可能成为优于２乙基己基膦酸单２乙基己基酯（ＨＥＨ／...     

Investigation of the extraction complexes of light lanthanides(III) with bis(2,4,4-trimethylpentyl)dithiophosphinic acid by EXAFS,IR, and MS in comparison with the americium(III) complex

The structure of the extraction complexes of light lanthanides (La(III), Nd(III), Eu(III)) with bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HBTMPDTP) have been characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), IR, and MS; the IR spectrum of the extraction complex of (241)Am with HBTMPDTP has been studied too. The molecular formula of the extraction complexes of lanthanides is deduced to be HML(4).H(2)O (M = La, Nd, Eu; L = anion of HBTMPDTP). The coordination number of Ln(III) in the complexes is 8; the coordinated donor atoms are 7 sulfur atoms from 4 HBTMDTP molecules and 1 O atom from a hydrated water molecule. With the increase of the atomic number of Ln, the coordination bond lengths of Ln-O and Ln-S decrease in the complexes. For La(III), Nd(III), and Eu(III), the coordination bond lengths of Ln-O are 2.70, 2.56, and 2.50, respectively, the coordination bond lengths of Ln-S are 3.01, 2.91, and 2.84, respectively, and the average distances between Ln and P atoms are 3.60, 3.53, and 3.46, respectively. The structure of the extraction complexes of Ln(III) with HBTMDTP is different from that of the Am(III) extraction complex. The results of IR show that there is no water coordinated with Am in the extraction complex. The molecular formula of the complex of Am(III) is deduced as being HAmL(4), and there are 8 S atoms from 4 HBTMPDTP molecules coordinated with Am. Composition and structure differences of the extraction complexes may be one of the most most important factors affecting the excellent selectivity of HBTMPDTP for Am(III) over Ln(III).     

Kinetics of the hydrolysis of ethers of bis(chloromethyl)phosphinic acid

Conclusions A study was made of the hydrolysis kinetics of some esters of bis(chloromethyl)phosphinic acid in water at 75–95°. The reaction rate depends on the nature of the alcohol radical, and for the alkyl radicals is determined by the steric factor.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1654–1655, September, 1966.     

The first separation and stereochemical determination of bis(α-hydroxyalkyl) phosphinic acids diastereoisomers

A separation of bis(α-hydroxyalkyl) phosphinic acid diastereoisomers is described. A novel method for the determination stereochemistry of bis(α-hydroxyalkyl) phosphinic acid diastereoisomers has been developed. The stereochemistry of one diastereoisomer was confirmed after converting to the corresponding methyl ester using trimethyl orthoformate.