Direct extraction of Mo(Ⅵ) from sulfate solution by synergistic extractants in the rotation column

Direct extraction of molybdenum from sulfate solution with synergistic extractants(mixture of D2EHPA and TBP)was studied in the rotation column.The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments.The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase.In the continuous experiments,the effect of different operating parameters such as speed of agitation,inlet solvent flow rate and inlet aqueous flow rate on the holdup,mean drop size,drop size distribution,slip and characteristic velocities and extraction percentage were examined.Modified correlations were proposed for prediction of hydrodynamic parameters with consideration of reaction extraction condition in the rotation column.Furthermore,these correlations were compared with the experimental data.According to the results,the direct extraction of Mo(Ⅵ)from aqueous solution and sulfuric media with extraction efficiency of 90.4%was obtained at higher rotor speed(240 r·min–1 rpm)in this column.

Separation of Indium and Iron from Dilute Sulphate Solutions with a Phosphorous Mixer Extractant

The phosphorous mixer introduced could replace D2EHPA as an extractant applied in the extraction of indium. The extraction properties of the phosphorous mixer were studied. The influences of extractant concentration, organic/aqueous (O/A) phase ratio, equilibrium time, and pH value of the feed solutions on the extraction of indium, and separation of indium-iron were investigated experimentally. Under the best operating conditions, more than 98% of indium. was extracted through two-stage counter-current extraction. The optimizing condition of indium extraction is determined as follows: O/A = 1 : (9-12) in volume ratio; 30% PPD in sulphonated kerosene; pH of the feed, about 0.6; equilibrium time, 3-5 min. The extractant has good reusing and anti-aging properties.

Recycle use of phosphorous mixer extractant to extract indium

The stripping and regeneration of the loaded organic phase of phosphorousmixer extractant (PPD) were studied. The mixed solutions (3 mol/L HCl +2 mol/L ZnC1_2) were used asthe stripping agent and more than 99 percent of indium can be stripped after three-stage strippingwhen the volume ratio of organic phase to stripping agent is 1:1. The organic phase can he recycledto use alter regeneration with HCl. The parallel contrast experiments with D_2EHPA (di-2-ethyl hexylphosphoric acid) were carried out under the same conditions. The results show that the mixerextractant has good reusability and the stripping and regeneration of PPD are superior to those ofD_2EHPA.

Study on the Synergistic Extraction of Ytterbium with 1－Phenyl－3－Methyl－4－（α－Furoyl）－5－Pyrazolone and Neutral Extractant

The extraction of Yb3+ by HA [1-phenyl-3-methyl-4-(α-furoyl)-5-pyrazolone] and by HA in combination with a neutral extractant B in toluene have been studied, where B represents n-butyloctyl sulfoxide (BOSO), n-pentylhexyl sulfoxide (PHSO), ethyl-n-dodecyl sulfoxide (EDSO), diphenyl sulfoxide (DPSO) or TBP. The composition of the synergistic extraction complexes have been shown to be YbA3·B and their extraction equilibrium constants have been determined separately.

DOUBLE SYNERGISTIC EFFECTS AND EXTRACTION KINETICS OF A MICELLE MIXED EXTRACTANT SYSTEM I DOUBLE(KINETIC AND THERMODYNAMIC)SYNERGISTIC EFFECTS AND EXTRACTION MECHANISMS

The equilibria and kinetic characteristics of a micelle mixed extractant system-D2 EHPA-MPA（MPA-monoalkyl phosphoric acid with long carbon chain and micellization）in extractionof the Al3+ions were studied.It was found that the system has double synergistic effects on theextraction of the Al3+ions.The compositions of the synergistic complexes were determined andthe synergistic reaction equations were obtained.

Linear Free Energy Relationships in Extraction of Rare Earths by Acidic Organophosphorus Extractants

The correlation relationships of apparent extraction equilibrium constant (1gK(ex)) with the electronic effect parameter( Sigma sigma(Phi)) and the steric effect parameter ( Sigma upsilon ) of the substituents in extractant molecules are investigated by linear regression analysis in the extraction of rare earths by various classes and structures of monoacidic organophosphorus extractants. The results indicate that in Linear free energy relationship formula 1gK(ex) = rho Sigma sigma(Phi) + psi Sigma upsilon + h generally follows for this kind of extraction systems. Accordingly, the quantitative structure-behaviour relationships of extractants are discussed. These relationships can be preliminarily applied to predict the 1gK(ex) values of rare earth extraction with definite structures of this class of extractants, and thus can provide some directions for the design of new RE extractants.

Quantum Chemical Calculation on the Structures and Electronic Properties of Phosphonate Ester as Rare Earth Extractants

Molecular mechanics, molecular dynamics and semi empirical quantum chemical method have been used to study the geometric and electronic structures of six phosphonate ester as rare earth extractants. The results show that the phosphorus atom exhibits sp 3 hybridization. The structures of the extractants are determined by the repulsion of the hydrocarbon groups. In the extractants that have two 2 ethyl hexyl groups, one 2 ethyl hexyl extends straight, and the other extends twistily. When the number of oxygen atom decreases, the negative charge of the phosphoryl oxygen atom increases, but the negative charge of oxygen atom and the positive charge of hydrogen of the hydroxyl group decreases, and the energies of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital(LUMO) increase. The energies of the occupied frontier orbitals are close to each other.

Influence of Modifiers, Extractants, and Trappers on Lipid Composition with Liquids in Standard State Extraction, Supercritical Fluid Extraction and Trapping by Supercritical Fluid Extraction, Part II

Modifiers have a broad array of influences on extraction with liquids in standard state, supercritical fluid extraction (SFE), trapping by SFE and supercritical fluid chromatography (SFC). They can significantly change the qualitative and quantitative results. Quantitative and qualitative results can be influenced by different extractants and modifiers in different ways as it was shown by Brondz et al. at 2007 in “The real nature of the indole alkaloids in Cortinarius infractus: Evaluation of artifact formation through solvent extraction method development”, J. Chromatography A, 1148, 1-7. The choice of correct extractant, modifier, and trapper to the bulk mobile phase for supercritical fluids (SFs) or for liquids in subcritical or in the liquids in standard state is a challenge in any extraction procedure. This is the second paper in a sequence that describes the influence of extractants and modifiers on the performance of SFs and results of extraction with liquids in standard state and SFE. Here, attention is given to possible mistakes in qualitative and quantitative results by poor understanding of the influence of extractants, modifiers, and trappers on extraction and trapping process by a careless choice of extractant, modifier, and trapper for extraction with liquids in standard state and SFE. The SF chosen for discussion in the paper is CO2. However, similar effects can be observed with use of other SFs and fluids in subcritical and standard states. In this paper, the discussion of lipids, fatty and carboxylic acids have been chosen as target analytes for extraction, trapping and analysis. Some examples from extraction with liquids in the standard state and trapping in the supercritical state (collection) have been furnished with the wrong extractant, modifier, or trapper which is presented for illustration of inappropriate choice of extractants, modifiers, and trappers.

Monoalkyl Esters of Isoalkylphosphonic Acid as Extractants in Rare Earth Separation

Four monoalkyl esters of isoalkylphosphonic acids have been studied for the chromatographic separation of rare earths (RE).The relationship between distribution ratios and acid concentration of the eluants for samarium and ytterbium has been explored.The characteristics of these extractants loaded onto macroreticular poly (methyl methacrylate) resin beads for the separation of lanthanum,cerium,praseodymium and neodymium have been compared.Among the extractants studied,mono(1-methylheptyl) ester of isooctylphosphonic acid was found to be the best for RE separation.The acidity for separation is lower than any known P-containing extractants for the same purpose.For instance,with 1.73 mol·L^(-1) nitric acid as eluent,thulium,ytterbium and lutetium can be separated quantitatively.The extractant-loaded resins possess high column efficiency with good kinetic characteristics.The extraction mechanism was also explored.

Effect of Extractant and Temperature on Phenolic Compounds and Antioxidant Activity of Selected Spices

Ten spices marketed in Jordan, (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L.,Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculum vulgare Mill and Laurus nobilis L.) were investigated for their phenolic compounds and antioxidant activity. The influence of different extractants (methanol, ethanol and acetone) at different temperatures (20, 40 and 60°C) was examined. Results showed at 60°C using methanol, cloves had the highest level of total phenolics (781.0 mg GAE/100g using acetone). At 40°C, sumac and cloves had the highest amounts of total phenolics (343.9 mg/100g and 342 mg GAE/100g respectively). At 20°C, cloves continued to have the highest amount of total phenolics (394.7 mg/100g) using methanol as extactant. Ethanol as extractant, cloves gave the highest level of phenolics (548 mg GAE/100g, 493.4 mg GAE/100g) at 60°C, while at 20°C cloves and sumac showed the highest concentrations of phenolics (350.8 mg GAE/100g and 342.8 mg GAE/100g respectively). Acetone as extractant at 60°C, cloves had the highest levels of phenolics (781 mg GAE/100g) while at 40°C and at 20°C, sumac contributed the highest levels of total phenolics (583.2 mg GAE/100g and 754.5 mg GAE/100g). The total phenolics concentration varied significantly among the spices. Their values varied according to the extractant and extracting temperature. IC50 (radical scavenging activity) reflecting the antioxidant activity was presented. Results showed that cloves had the highest antioxidant activity while the cinnamon, turmeric and sumac had a appreciable level of antioxidant activity. Green cardamom and coriander had the lowest antioxidant activity. Antioxidant activity was positively correlated with total phenolic compounds content of the investigated spices.

Evaluation and Comparison of DTPA Extractanting Methods for Available Cationic Micronutrients in Non-acidic Soils of Andhra Pradesh,India

The research work was carried out to compare and evaluate the extractability of cationic micronutrients(Zn,Cu,Fe and Mn)using widely employed diethylene triamine pentaacetic acid(DTPA)-triethanolamine(TEA)-CaCl2 method with that of multinutrient extractant(ammonium bicarbonate(AB)-DTPA)in Inceptisols,Alfisols and Entisols in the erstwhile united Andhra Pradesh.The percent variation of extraction of Zn was higher in soils with DTPA-TEA-CaCl2 over AB-DTPA method in all the soil orders(types)in the range of 35.3% to 46.2%.AB-DTPA extracted high amounts of Cu to an extent of 10%-21% in Entisols and Alfisls,respectively.In Inceptisols both extracatants extracted equal amounts of Cu.AB-DTPA extracted high amounts of Fe 13% and 18% in Alfisols and Entisols compared to that of DTPA-TEA-CaCl2 method and DTPA-TEA-CaCl2 method was good extract for Fe in Inceptisols and even for Mn in Alfisols.The amounts of micronutrient contents extracted were found to be highly and significantly correlated with soil properties like electrical conductivity(EC)and organic carbon(OC).The individual micronutrient contents of Zn,Cu and Fe extracted by DTPA-TEA-CaCl2 methods were found to be highly correlated with that of AB-DTPA extractant.However,such correlation was not observed for Mn extraction when all soils were grouped.

Comparative Study on the Effect of Extractant on the Detection of Imidaclothiz Residue in Tea

Imidaclothiz residue in tea was determined by high performance liquid chromatography（ HPLC）,using different extractants including hexane,acetonitrile,acetone,hexane-acetonitrile（ 1∶ 1）,acetonitrile-acetone（ 1∶ 1） and hexane-ethyl acetate（ 1∶ 1）. The results indicated that all the extractants displayed excellent extraction capacities of imidaclothiz residue in tea and insignificant interference on the accuracy. Under the optimized extraction volume（ 20 ml）,the recovery values were in the ranges of 82. 3%-100. 7%,85. 8%-101. 1%,85. 9%-95. 2%,82. 3%-101. 3%,82. 4%-100. 5% and 88. 6%-102. 3%,respectively,with the relative standard deviations smaller than 10%. Moreover,mixed solvent showed improved extraction capacity,and the highest extraction capacity and promoted stability were approached by using hexane-ethyl acetate（ 1∶ 1） as coextractants.

Synergistic extraction of cerium from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester and Di-(2-ethyl hexyl) phosphoric acid as extractant

Synergistic extraction of cerium（IV） from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester（HEH/EHP, HL） and Di-（2-ethyl hexyl） phosphoric acid（HDEHP, HA） as extractant was investigated.The results indicated that the maximum synergistic enhancement coefficients were obtained at the mole fraction of HEH/EHP=0.6, and cerium（IV） was extracted into organic phase in the form of Ce（SO4）0.5HL2A2.A cation exchange mechanism was proposed for the synergistic extraction of Ce（IV）.The equilibrium constants and thermodynamic functions such as △G, △H, and △S were determined in the extraction of Ce（IV） from sulfuric medium using mixture of HEH/EHP and HDEHP.

Separation of middle rare earths by solvent extraction using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant

The extraction of the trivalent middle rare earths from chloride media by kerosene solutions of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant was studied. The separation factors between the elements using solution simulating wastes from NiMH spent batteries have been evaluated: the order of the extractive ability of extractant can be confirmed in Tb>Gd>Eu>Sm.

The pilot test of Pt-Pd and Pt-Rh feeds extracted and separated with a new sulfoxide extractant

Platinum, palladium and rhodium of the raw feeds extracted and separated with a new sulfoxide extractant （MSO） were studied in the paper. The pilot test results showed that the percentage extractions are more than 99% for platinum and palladium in Pt-Pd feed, and the percentage strippings are 100% and 99.2% with HCl and ammonia, respectively. The ratio of palladium to platinum is 0.0016 in stripping platinum solution, and the ratio of platinum to palladium is 0.0020 in stripping palladium solution. The percentage extraction of platinum is 99% in Pt-Rh feed, and the percentage stripping is 100%. The ratio of rhodium to platinum is 0.0002 in stripping platinum solution. Therefore, platinum, palladium, and rhodium feeds are separated effectively with MSO.

Rare Earth Separation with 1-Hexyl-4-Ethyloctyl Isopropylphosphonic Acid Extractant

A new extractant 1 hexyl 4 ethyloctyl isopropylphosphonic acid (HHEOIPP or HA) in heptane was employed to extract rare earths from hydrochloric acid medium. The dependence of extraction distribution ratio on equilibrium aqueous pH and the concentration of extractant were investigated. On the basis of slope analysis, it was proposed that two different kinds of extracted species were formed. For rare earth elements (La～Ho) the extracted species was LnA 3(HA) 3 and for heavy rare earth elements (Er～Lu) the species was LnClA 2(HA) 3. The steric hindrance plays an important role in forming the species. The extraction constants and separation factors of the adjacent rare earths were calculated too. Compared with HDEHP and HEH/EHP, HHEOIPP is a valuable extractant with high separation selectivity. The “tetrad effect” between K ex and atomic number was observed.

Solvent extraction separate of zinc and cadmium from magnesium and calcium in sulfuric acid medium by mixing extractants

Synergistic extraction has been proven to enhance extractability and selectivity for the separation of cadmium and zinc from magnesium and calcium in the sulfuric acid medium with Mextral V10 and Mextral 622H(aromatic hydroxamic)mixtures diluted in DT100.Mixtures of Mextral V10 and 622H are highly selective for Zn and Cd over Mg and Ca compared with the single Mextral V10,resulting in larger synergistic shifts for zinc and cadmium with theΔpH_(50(Zn–Ca))values increasing substantially from0.83 to 1.73 pH units andΔpH_(50(Cd–Ca))values increasing from 0.63 to 2.13 p H units.The aqueous to organic ratio(A/O ratio),the saponification ratio of Mextral V10 and extracting agent concentration were studied on the effect of metal ions extraction,which helped to increase the organic capacity of metal extraction.The Mc Cabe-Thiele plot for Cd and Zn extraction with 5%(volume fraction)Mextral V10 and 5%Mextral 622H extractants mixture indicate the necessity of only one theoretical stages at an A/O ratio of 1.5:1.One stage extraction simulation test conducted at pH 6.50 shows that Cd and Zn reach the extraction of 99.6%and 97.9%,respectively,and only low levels of magnesium and calcium are extracted in the organic phase.The extracted Zn^(2+)or Cd^(2+)-organic species are Zn(A_1)(A_2)or Cd(A_1)(A_2)with the mixture system by slope analysis.

Extraction of palladium(Ⅱ) from hydrochloride solutions with 2-n-octyl-4-isothiazolin-3-one as novel extractant

Solvent extraction of palladium （Ⅱ） from hydrochloric acid solution with 2-n-octyl-4-isothiazolin-3-one （OIT）/cyclohexane was studied. Effects of different parameters on extraction efficiency were evaluated. 99.96 % and 98.26 % palladium （Ⅱ） could be effectively extracted with 0.018 mol·L^-1 OIT/cyclohexane of 0.1 and 4.0 mol·L^-1 HCl medium, respectively. Nonpolar solvent and low acidity could improve the extracting efficiency, and successfully strip palladium （Ⅱ） from the loaded organic phase was achieved with 0.5 mol·L^-1 （NH2）2CS solution. It was proposed that the extraction of Pd com-plexes from HCl medium proceeded through the ion-association mechanism by slope method, NMR and FF-IR spectra.

Dialkyl phosphinic acids:Synthesis and applications as extractant for nickel and cobalt separation

Three kinds of dialkylphosphinic acids(DAPAs),i.e.dihexylphophinic acid(DHPA),di-(2,4,4-trimethylpentyl) phosphinic acid(DTMPPA)and didecylphophinic acid(DDPA),were synthesized through free radical addition reaction.The influence of the types of initiator,reation time and reaction temperature on the yield of DAPAs were investigated.The products were characterized by NMR and MS.By using DHPA,DTMPPA and DDPA(10%in kerosene)as extractants,the extraction of Co2 +and Ni2 +in sulphate medium at different equilibrium pH values were measured.The results show that the maximum yield of DHPA, DTMPPA and DDPA can all be achieved at about 130℃under the initiation of di-tert-butyl peroxide(DTBP).All the extraction of cobalt with respect to DHPA,DDPA and DTMPPA precedes that of nickel.The difference in pH1/2 value(defined as the pH at which 50%metal extraction occurs)between cobalt and nickel increases in the following sequence from large to small:DHPA,DDPA and DTMPPA,which indicates that the separation ability for cobalt and nickel ascends from DHPA,DDPA to DTMPPA.

Binary Mixture of Tri-Octyl Amine and Cyanex 923 as Extractant for the Extraction of Zr (IV) from Acidic Chloride Medium

The extraction of zirconium (IV) from aqueous HCl solution by binary mixture TOA and Cyanex 923 using kerosene as diluent was studied. The effect of parameters like aqueous phase acid concentration, extractant concentration, chloride ion concentration, diverse ion effect, metal loading, nature of diluents and temperature on the extraction of Zr (IV) was investigated. The percentage of extraction of Zr(IV) became 100% with 0.1 M TOA and 0.01 M Cyanex 923 from 7 M HCl and also from 4 M HCl with 0.1 M TOA and 0.02 M Cyanex 923. Benzene was found to be effective diluent for the extraction of Zr(IV) with binary mixture of TOA and Cyanex 923. The positive enthalpy change and positive entropy change in the binary extraction system show endothermic process with increase in randomness. Stripping of Zr (IV) from the loaded organic phase containing mixture of TOA (0.1 M) and Cyanex 923 (0.01 M) indicated that HNO3 and Na2CO3 are the best stripping agents.