Equilibrium Distribution Coefficients Research Articles

Investigation on Ti-6Al-4V Microstructure Evolution in Selective Laser Melting

Selective laser melting (SLM) is an advanced additive manufacturing technique that can produce complex and accurate metal samples. Since the process performs local high heat input during a very short interaction time, the physical parameters in the solidification are difficult to measure experimentally. In this work, the microstructure evolution of Ti-6Al-4V alloy in additive manufacturing was studied. With the increase of scanning speed, the cooling rate and the temperature gradient of molten pool position increased, which was attributed to the gradual decrease of energy density. The phase-field simulation resulted in the overall microstructure morphology of columnar crystals owing to the very large temperature gradient and cooling rate obtained from the temperature field. Microsegregation was observed during dendritic formation, and the solute was enriched in the liquid phase near the dendritic tip and between the dendritic arms due to the lower equilibrium distribution coefficient. The scanning speed had an effect on the dendrite spacing.

Porous lithium ion sieves nanofibers: General synthesis strategy and highly selective recovery of lithium from brine water

Lithium ion sieves (LIS) have gained great interest in lithium recovery. However, the synthesis of high stability, selectivity, and adsorption capacity of LIS is still a great challenge. Here, a general strategy combining electrospinning and calcination techniques is developed to fabricate a series of porous titanium-based LIS nanofibers. The porous structure created by calcination increases the exposure of the adsorption sites, which significantly accelerates the deintercalation and intercalation of Li+ from and into the vacancies in the framework. All of samples have good Li+ adsorption capacity and high selectivity for Li+. As a proof of concept, porous H4Ti5O12 nanofibers (P-HTO-NF) transformed from the electrospun porous Li4Ti5O12 nanofibers (P-LTO-NF) are systematically investigated in lithium recovery. P-HTO-NF possesses a superior adsorption capacity (59.1 mg/g), which is nearly close to the theoretical value (63.77 mg/g). The Freundlich isotherm model can well describe the adsorption isotherm data. The adsorption equilibrium can reach within 30 min (C0 = 300 mg/L, pH = 11, S/L = 60 mg/60 mL). The equilibrium distribution coefficient (Kd, mL/g) for Li + (232) is extremely higher than that for competing ions (1.41 for Na+, 1.17 for K+, 0.88 for Mg2+, 0.58 for Ca2+) (C0 = 40 mg/L for Li+, pH = 8), indicative of a highly selective recovery of lithium from brine water. The LIS show excellent stability with a low Ti dissolution and the adsorption capacity for Li+ remains 86.5% after 6 cycles. Our work provides a universal strategy for the synthesis of porous LIS.

Simulation of Marangoni convection effects on the hydrodynamics of liquid–liquid extraction drops

Concentration induced Marangoni convection (MC) effect has many applications in the chemical engineering processes. In this study, the MC effects have been investigated in the toluene/acetone/water (T/A/W) liquid–liquid extraction system, focusing on the mass transfer and hydrodynamics. For the first time, the VOF-CSS model has been used, and the mass transfer equation has been coupled with the hydrodynamic equations of the VOF model, using the surface tension force model of the CSS. A single mass transfer equation has been solved for the two phases, modifying the unsteady, convective, and diffusive terms based on the equilibrium distribution coefficient. The MC effect has been implemented in the CSS surface tension model with a concentration-dependent surface tension coefficient. Simulations have been carried out in 1, 1.5, and 2 mm drops in the wide range of concentration (0.9–30 g/L). Good agreements have been achieved for the concentration and reduced velocity values compared with the existing experimental data. Simulation results showed that the reduced velocity values remain almost constant for every drop diameter, in the initial concentration range from 3.7 to 30 g/L. The reacceleration time for the three drop sizes with the different initial concentrations has been obtained from the simulation results and compared. The MC effects on the axial velocity profiles and drag coefficients were also reported providing comprehensive information about the MC effects on the hydrodynamics.

Magnesian calcite solid solution thermodynamics inferred from authigenic deep-sea carbonate

Abstract Magnesian calcite is perhaps the most well studied solid solution in the geosciences due to the widespread use of marine carbonates to reconstruct paleoenvironment. Despite decades of research, the low temperature thermodynamic properties of magnesian calcite in seawater are poorly constrained, largely because very slow reaction kinetics prevent the direct measurement of equilibrium distribution coefficients (KdMg) for anhydrous Mg-bearing minerals. In this study, we use the Mg content of authigenic calcite formed in deep-sea marine carbonate sediments to determine the dependence of KdMg on temperature and aqueous Mg/Ca between ∼2 and 25 °C. We find that the solid activity coefficient of magnesite in Mg-calcite is strongly temperature dependent in this range, leading to predicted exsolution of Mg at low temperatures. At the temperatures typical of ocean bottom water, equilibrium Mg distribution coefficients are at least an order of magnitude lower than values inferred from inorganic calcite growth experiments. Moreover, the equilibrium temperature dependence of KdMg agrees well with field-based paleotemperature calibrations determined for low-Mg benthic and planktonic foraminifera at temperatures

Elemental micro-segregation characteristic of fiber laser welded Hastelloy C-276 sheet

Abstract The elemental micro-segregation characteristic within the weld zone for ytterbium fiber laser welded Hastelloy C-276 sheet was investigated. The analysis of segregation ratio and equilibrium distribution coefficient of elements, determined through EDS data, indicate the reduction in micro-segregation of elements compared with the previous reported literatures for laser welded Hastelloy C-276. High melting efficiency of ytterbium fiber laser, reduction in the amount of linear heat input, and high cooling rate of the mushy zone lead to the reduction in micro-segregation. The melting efficiency of ytterbium fiber laser for welding of Hastelloy C-276 of 64% is higher than that (48%) of conventional welding methods. High melting efficiency leads to the reduction in the linear heat input required for welding. Hence, in the present investigation, the same was found to substantially reduce as compared to the previous reported literature. The cooling rate from liquidus temperature to solidus temperature at the weld centerline was found to be in the order of 103 °C/s. Cellular dendritic substructure that constituted for lower micro-segregation was formed at the weld centerline.

Quantifying Size Exclusion by Diffusion NMR: A Versatile Method to Measure Pore Access and Pore Size.

Size-exclusion quantification NMR spectroscopy (SEQ-NMR) is introduced for measuring equilibrium distribution coefficients, Keq, in porous media. The porous medium is equilibrated with a polydisperse polymer solution. The original bulk polymer solution and the polymer solution after equilibration but in the absence of the porous medium are analyzed by NMR diffusion experiments. The joint evaluation of the two diffusion attenuation curves under suitable constraints provides the extent by which polymer fractions of particular size were depleted from the solution by pore access. This procedure yields Keq versus polymer probe size, the selectivity curve that in turn can provide the pore size and its distribution. Simulations probe the performance of the method that is demonstrated experimentally in chromatographic media using dextran polymers. SEQ-NMR and inverse size-exclusion chromatography (ISEC) yield selectivity curves that virtually coincide. Crucial advantages with SEQ-NMR, such as versatility with regard to both the polymer used and porous system explored, high speed, potential for automation, and small required sample volume, are discussed.

Separation of Protactinium Employing Sulfur-Based Extraction Chromatographic Resins.

Protactinium-230 ( t1/2 = 17.4 d) is the parent isotope of 230U ( t1/2 = 20.8 d), a radionuclide of interest for targeted alpha therapy (TAT). Column chromatographic methods have been developed to separate no-carrier-added 230Pa from proton irradiated thorium targets and accompanying fission products. Results reported within demonstrate the use of novel sulfur bearing chromatographic extraction resins for the selective separation of protactinium. The recovery yield of 230Pa was 93 ± 4% employing a R3P═S type commercially available resin and 88 ± 4% employing a DGTA (diglycothioamide) containing custom synthesized extraction chromatographic resin. The radiochemical purity of the recovered 230Pa was measured via high purity germanium γ-ray spectroscopy to be >99.5% with the remaining radioactive contaminant being 95Nb due to its similar chemistry to protactinium. Measured equilibrium distribution coefficients for protactinium, thorium, uranium, niobium, radium, and actinium on both the R3P═S type and the DGTA resin in hydrochloric acid media are reported, to the best of our knowledge, for the first time.

Сорбционная способность ультрафильтрационных мембран и потенциал поля поверхностных сил в растворах молочных белков

В работе представлен анализ литературных данных по исследованию сорбционной способности мембран и потенциала поля поверхностных сил. Сформулирована цель работы и на основании литературного обзора выполнен выбор исследуемых ультрафильтрационных мембран УАМ­150 и УПМ-100. Методом переменных концентраций проведены экспериментальные исследования по сорбционной активности ультрафильтрационными мембранами белка из подсырной сыворотки. Получены численные значения равновесного коэффициента распределения белка в мембранах УАМ-150 и УПМ-100, и растворах молочной сыворотки в диапазоне изменения концентраций белка от 9 до 32 г/л при температурах от 293 до 308 К. Проанализировано влияние температуры и концентрации раствора молочного белка на сорбционную способность ультрафильтрационных мембран УАМ-150 и УПМ-100. На основании экспериментальных данных найдены численные значения эмпирических коэффициентов для теоретического расчета равновесного коэффициента распределения. Рассчитан потенциал поля поверхностных сил полупроницаемых мембран УАМ-150 и УПМ-100 и интерпретировано его изменение в зависимости от температуры и концентрации молочного белка

DETERMINATION OF THERMODYNAMIC QUANTITIES OF BINARY METAL SYSTEMS WITH LOW SOLUBILITY OF COMPONENTS IN THE SOLID α-PHASE

The method for determining the thermodynamic quantities: the partial enthalpy of dissolution , the activity coefficients and activities of the second component B in binary metallic systems with low solubility in the solid α-phase has been proposed. The algorithm for determining the above values is a sequence of preliminary calculations of the limiting and equilibrium distribution coefficients and construction of saturated solid solution lines for such systems with low solubility of the second component. Preliminarily obtained data are necessary for determining the partial enthalpy of dissolution and other quantities in the systems under study. Such a sequence of calculations is the proposed method for determining the thermodynamic parameters of dissolution. The values and temperature dependences of the dissolution enthalpy of component having a low solubility for such systems as Cd-Na, Cd-Tl, Te-Ga, Te-As, Te-Cu, Zn-Sn, as well as the activity coefficients and the activities of the second component in the saturating α-phase in these systems were determined. An analysis of obtained results on the enthalpy of dissolution shows that a change in the partial enthalpy with a change in the dissolution temperature is observed. When the temperature decreases from the melting point of the pure main component to the eutectic temperature, an increase in the partial enthalpies of dissolution of the second component is observed for studied systems. The Te-Ga system is characterized by a negative value . A negative value indicates an exothermic process of gallium dissolution in tellurium, in contrast to other systems in which the dissolution of the second component occurs with heat absorption. Analyzing the enthalpy of dissolution in the systems under study, it should be noted that the low values of < 2000 J/mol are characterized by the systems Cd-Na and Te-Ga. For systems Te-Cu, Te-As, Te-Tl, Zn-Sn > 15000 J/mol. Systems with a value > 15000 J/mol reveal a tendency to the occurrence of retrograde solubility in them. The difference in values is found to be more than two orders of magnitude for different systems.

Chromatographic separation of the theranostic radionuclide 111Ag from a proton irradiated thorium matrix

Column chromatographic methods have been developed to separate no-carrier-added 111Ag from proton irradiated thorium targets and associated fission products as an ancillary process to an existing 225Ac separation design. Herein we report the separation of 111Ag both prior and subsequent to 225Ac recovery using CL resin, a solvent impregnated resin (SIR) that carries an organic solution of alkyl phosphine sulfides (R3P = S) and alkyl phosphine oxides (R3P = O). The recovery yield of 111Ag was 93 ± 9% with a radiochemical purity of 99.9% (prior) and 87 ± 9% with a radiochemical purity of 99.9% (subsequent to) 225Ac recovery. Both processes were successfully performed with insignificant impacts on 225Ac yields or quality. Measured equilibrium distribution coefficients for silver and ruthenium (a residual contaminant) on CL resin in hydrochloric and nitric acid media are reported, to the best of our knowledge, for the first time. Additionally, measured cross sections for the production of 111Ag and 110mAg for the 232Th(p,f)110m,111Ag reactions are reported within.

Equilibrium boron distribution between Fe–C–Si–Al melt and boron-bearing slag

HSC 6.1 Chemistry software (Outokumpu) and a simplex–lattice experiment design are employed in thermodynamic modeling of the equilibrium boron distribution between steel containing 0.2% C, 0.35% Si, and 0.028% Al (wt % are used throughout) and CaO–SiO2–Al2)3–8% MgO–4% B2O3 slag over a broad range of chemical composition at 1550 and 1600°C. For each temperature, mathematical models (in the form of a reduced third-order polynomial) are obtained for the equilibrium boron distribution between the slag and the molten metal as a function of the slag composition. The results of simulation are presented as graphs of the composition and equilibrium distribution of boron. The slag basicity has considerable influence on the distribution coefficient of boron. For example, increase in slag basicity from 5 to 8 at 1550°C decreases the boron distribution coefficient from 160 to 120 and hence increases the boron content in the metal from 0.021% when L B = 159 to 0.026% when L B = 121. In other words, increase in slag basicity favorably affects the reduction of boron. Within the given range of chemical composition, the positive influence of the slag basicity on the reduction of boron may be explained in terms of the phase composition of the slag and the thermodynamics of boron reduction. Increase in metal temperature impairs the reduction of boron. With increase in temperature to 1600°C, the equilibrium distribution coefficient of boron increases by 10, on average. On the diagrams, we see regions of slag composition with 53–58% CaO, 8.5–10.5% SiO2, and 20–27% Al2O3 corresponding to boron distribution coefficients of 140–170 at 1550 and 1600°C. Within those regions, when the initial slag contains 4% B2O3, we may expect boron concentrations in the metal of 0.020% when L B = 168 and 0.023% when L B = 139.

Radiometric evaluation of diglycolamide resins for the chromatographic separation of actinium from fission product lanthanides

Actinium-225 is a potential Targeted Alpha Therapy (TAT) isotope. It can be generated with high energy (≥ 100MeV) proton irradiation of thorium targets. The main challenge in the chemical recovery of 225Ac lies in the separation from thorium and many fission by-products most importantly radiolanthanides. We recently developed a separation strategy based on a combination of cation exchange and extraction chromatography to isolate and purify 225Ac. In this study, actinium and lanthanide equilibrium distribution coefficients and column elution behavior for both TODGA (N,N,N′,N′-tetra-n-octyldiglycolamide) and TEHDGA (N,N,N′,N′-tetrakis-2-ethylhexyldiglycolamide) were determined. Density functional theory (DFT) calculations were performed and were in agreement with experimental observations providing the foundation for understanding of the selectivity for Ac and lanthanides on different DGA (diglycolamide) based resins. The results of Gibbs energy (ΔGaq) calculations confirm significantly higher selectivity of DGA based resins for LnIII over AcIII in the presence of nitrate. DFT calculations and experimental results reveal that Ac chemistry cannot be predicted from lanthanide behavior under comparable circumstances.

Negative rejection of nonionic dye in aqueous alcohol solutions during nanofiltration by hydrophobic membranes

This paper reports that nonionic dye (“Oil Red O”) is negatively rejected during nanofiltration of its aqueous ethanol solution by hydrophobic membranes made of high-permeability glassy polymers. This implies that the dye concentrates in the permeate region. A probable reason for the observed negative rejection is positive adsorption of the neutral dye molecules inside the membrane pores. Comparing samples of PTMSP- and PMP-based membranes we verify the slightly modified version of the “fine porous membrane” model proposed here. Based on our own experimental data for the rejection coefficient and the normalized flux (permeability) through both polymeric membranes in dependence on alcohol concentration under different values of applied pressure, we calculate the main physico-chemical parameters of these membrane systems, i.e. the diffusion and the equilibrium distribution coefficients of “Oil Red O” molecules inside the membrane. Comparing the theoretically predicted parameters to the experiment-based rejection-flux curves, we conclude that the PTMSP-based membrane is 4–11 times more permeable for the neutral dye than the PMP-based membrane, although both membranes have very similar values of the negative rejection coefficient. The diffusion coefficient of “Oil Red O” is 1.5–8 times higher inside the PTMSP membrane compared to the PMP membrane, while the distribution coefficients for both membranes are close to each other. It might mean that the PMP membrane has a denser structure than the PTMSP membrane. Both membranes can be effectively used to purify aqueous alcohol mixtures of different dyes.

Extraction-chromatographic properties and radiation resistance of a solid extractant based on di-2-ethylhexyl hydrogen phosphate

Extraction-chromatographic properties of LN-B200-S sorbent based on di-2-ethylhexyl hydrogen phosphate were studied. The equilibrium distribution coefficients of Am in the sorbent–HNO3 system, the total exchange capacity, and the capacity to breakthrough were determined. The influence of the absorbed dose on the above parameters was examined. The suggested extraction-chromatographic system was tested with a real solution of spent nuclear fuel from an RBMK-1000 reactor as applied to the recovery of the Am–Cm–Nd fraction.

The role of Fe content on the Fe-Mg exchange reaction in augite

The study of the intracrystalline Fe-Mg exchange between M 1 and M 2 crystallographic sites in clinopyroxene on samples a variety of geological settings has provided a framework to understand the thermal history of pyroxene-bearing rocks. The Fe-Mg exchange reaction has successfully been exploited as a geothermometric tool in the study of orthopyroxene and pigeonite-bearing rocks, but relatively few data are available for clinopyroxene. A strong correlation between total iron content and the slope of the Fe 2+ -Mg equilibrium distribution coefficient ( k D ) as a function of temperature has been found for orthopyroxene and pigeonite, and we investigate this relationship in augite. We carried out new equilibrium annealing experiments at 800, 900, and 1000 °C followed by single-crystal X-ray diffraction and structural refinement to obtain a new geothermometric calibration for augite from a 120 m thick lava flow from Ontario, Canada [Theo’s Flow, En 49 Fs 9 Wo 42 hereafter also referred as Fs 9 where Fs = 100·ΣFe/(ΣFe+Mg+Ca) with ΣFe = Fe 2+ +Fe 3+ +Mn]. This new calibration enabled us to evaluate the compositional effects (mainly Fe content) by comparison with the data previously obtained on augite from MIL 03346 martian sample (En 36 Fs 24 Wo 40 hereafter referred to as Fs 24 ). The extremely good agreement observed between the data obtained on Theo’s Flow and Miller Range (MIL 03346) augite demonstrate that for the range of compositions between Fs 9 and Fs 24 , total iron content has a negligible or null influence on equilibrium behavior. Furthermore, linear regression of data from Theo’s Flow and MIL 03346 gave a single calibration equation: ln k D = − 4040 ( ± 180 ) / T ( K ) + 1 . 12 ( ± 0 . 17 ) ( R 2 = 0 . 988 ) . This new calibration describes the equilibrium behavior of augite and can be reliably used to determine the closure temperature ( T c ) of augite with composition ranging between Fs 9 and Fs 24 .

Element Mobility and Behaviour of Zircon during HT Metasomatism of Ferroan Basic Granulite at Ayyarmalai, South India: Evidence for Polyphase Neoarchaean Crustal Growth and Multiple Metamorphism in the Northeastern Madurai Province

An exposure of polyphase, Neoarchaean–early Palaeoproterozoic basement rocks has been identified in the northeastern part (10°53·44'N, 78°22·88'E) of the Madurai Province. The dominant migmatitic charnockite contains older enclaves of isoclinally folded syenitic biotite gneiss and boudinaged mafic dykes. A highly evolved (Mg# 10) and high field strength element (HFSE) + rare earth element (REE)-enriched ferroan basic dyke body exhibits a distinct mineralogical zonation produced during intense syn-boudinage infiltration metasomatism, coeval with high-grade metamorphism and anatexis of the host charnockite. Core domains that preserve an anhydrous granulite assemblage (domain A: garnet, clinopyroxene and minor plagioclase) grade through a narrow mineralogical transition zone (domain B) into a broad amphibole-rich rind (domain C: ferropargasite + K-feldspar ± plagioclase, quartz). Pseudosection modelling and thermobarometry yields P–T estimates of ∼800 °C, 8 kbar for the granulite-facies metamorphism (M1) and ∼730 °C, 7 kbar for the high-grade metasomatism (M2). The changes in fabric, mineral assemblage and whole-rock chemistry across domains A to C reveal near-isovolumetric–isochoric conditions of infiltration-driven metasomatism and an unusual enrichment in large ion lithophile elements (LILE), REE, and HFSE, causing prolific neoblastesis of apatite and zircon, and attest attainment of chemical equilibrium. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) trace element analyses for major constituents and accessory phases in the metasomatic domains provide a new set of equilibrium distribution coefficients for the REE. LA-ICP-MS spot analyses of zircon in well-documented microstructural settings identified the following events: ∼2·67 Ga: intrusions of foid-bearing syenite and ferroan basic dykes during crustal extension; ∼2·6 Ga: high-grade metamorphism M1; ∼2·6 Ga: emplacement of voluminous arc-type intrusions (the protolith of charnockite); ∼2·48 Ga: high-grade metamorphism and anatexis M2 of the charnockite protolith and metasomatism of the ferroan metabasite. A distinct Pan-African overprint (M3, ∼610 Ma, 520 Ma) of the Palaeoproterozoic high-pressure rocks is manifested by hydration related to the exhumation of the deep-seated granulites to mid-crustal levels. This study confirms the continuation of Neoarchaean crust farther south beyond the perceived Palghat Cauvery shear zone system and contradicts the view that this shear zone system represents the Neoproterozoic–Cambrian suture zone along which the Mozambique Ocean was closed.

Equilibrium ion exchange studies of Zn2+, Cr3+, and Mn2+on natural bentonite

AbstractBentonite is a clay mineral often used in ion exchange processes due to its high ion exchange capacity. In the present study, a commercially available in Greece market bentonite was obtained and characterized by XRD, XRF, FTIR, BET, and TG/DTA analysis. Monmorillonite was the main component of bentonite sample (>80%). Ion exchange equilibria of Zn2+, Cr3+, and Mn2+ on bentonite was examined by use of batch equilibrium isotherms, distribution coefficients, and maximum exchange levels (MELs) under the same normality for all metals (0.01 N) at 25 ± 2°C. The equilibrium isotherms for the metals studied exhibit a favorable-type isotherm. Selectivity series deduced from equilibrium isotherms are Cr3+ > Zn2+ > Mn2+, and the same occurs for MELs. The Langmuir and Freundlich models were applied and fitted the equilibrium data for the metal ion uptake. A detailed literature review on heavy metals-bentonite equilibrium is provided.

Kinetics of Heavy Metal Dissociation from Natural Organic Matter: Roles of the Carboxylic and Phenolic Sites.

We developed a unifying model for the kinetics of heavy metal dissociation from natural organic matter (NOM) in this study. The kinetics model, integrated with the equilibrium model WHAM 7, specifically considered metal ion reactions with various NOM sites formed by the carboxylic and phenolic sites. The association and dissociation rate coefficients for metal reactions with various NOM sites were constrained by WHAM predicted equilibrium distribution coefficients at specific reaction conditions. We developed the relationship for the dissociation rate coefficients among different binding sites for each metal, which was internally constrained by the metal binding constants. The model had only one fitting parameter, the dissociation rate coefficient for the metal complexes formed with two weak carboxylic sites, and all other parameters were derived from WHAM 7. The kinetic data for metal dissociation from NOM were collected from the literature, and the model was able to reproduce most of relevant data analyzed. The bidentate complexes appeared to be the predominated species controlling metal dissociation under most environmental conditions. The model can help to predict the reactivity and bioavailability of heavy metals under the impact of multiple competing ligands including NOM.

New approach to characterization of hybrid nanocomposites

This paper presents a novel approach to the characterization of hybrid cation-exchange membranes by applying the “fine porous membrane” model. We verify this approach using samples of cation-exchange membranes synthesized on the base of the perfluorinated MF-4SC membrane and halloysite nanotubes and prepared by the casting method. For characterization we use the initial pure MF-4SC membrane and two hybrid membranes MF-4SC spatially modified with halloysite nanotubes encapsulated by Pt nanoparticles or intercalated by Fe nanoparticles. Based on our own experimental data for the diffusion permeability and specific conductivity in dependence on electrolyte concentration (HCl), we calculate the main physico-chemical parameters of these membrane systems, i.e. the ambipolar diffusion and equilibrium distribution coefficients of the electrolyte inside the membrane. Comparing the theoretically calculated parameters to the experimentally measured current-voltage curves, selectivity, transport numbers of cations and water for all the three samples we conclude that the hybrid membrane with platinum nanoparticles is superior to the other two membranes as far as fuel cells are concerned.

Recovery of copper(II) and chromium(III) from nitrate medium with salicylideneaniline dissolved in 1-octanol

The solvent extraction of copper(II) and chromium(III) from nitrate medium with salicylideneaniline (HL) is studied as a function of various parameters: pH, concentration of salicylideneaniline, contact time and the nature of anoin (nitrate and sulfate) in aqueous phase. Chromium(III) is not extracted by salicylideneaniline diluted in 1-octanol. Copper(II) is only extracted by salicylideneaniline and it was found that the highest extractability achieved to 95 % at pH 4.9, The stoichiometry of the extracted species was determined by using the method of slope analysis. Elemental analysis, UV–vis and IR-spectra were used to confirm the structure. It is found that the copper (II) is extracted as CuL 2 .2H 2 O Their equilibrium constant, distribution coefficient, percentage extraction ( %E ) and free energy are also calculated.