Ionic Liquid Cyphos Research Articles

New Insights on Y, La, Nd, and Sm Extraction with Bifunctional Ionic Liquid Cyphos IL 104 Incorporated in a Polymer Inclusion Membrane.

In this study, an ionic liquid-based polymer inclusion membrane (IL-PIM) made of (50% polymer-50% CyphosIL104) was used to extract and separate the rare earth elements (REEs) Y, La, Nd, and Sm in chloride solutions. The effect of extraction time and pH was studied to optimize the extraction and separation conditions. The four REEs were effectively extracted at pH 4-5 from both single and mixed metals solutions. However, at pH 2, only Y was extracted. The recovery of the extracted REEs from the loaded PIM was achieved using HNO3 and H2SO4. In the case of La, it was quantitatively back-extracted with H2SO4 after a contact time of 1 h, while up to 4 h was necessary to recover 70% of the extracted Y, Sm, and Nd. Extraction isotherms were studied, and the Freundlich isotherm model was the most adequate to describe the interaction between the PIM and the REEs. Finally, the developed PIM was investigated for the extraction of REEs from mixtures containing other metals, which showed great selectivity for the REEs.

Separation of Pd from Pt and Rh by solvent extraction method from waste solution

The paper investigated the possibility of extractive separation of palladium from platinum and rhodium with ionic liquid Cyphos IL 101. A technological solution obtained by dissolving waste materials was used as the test material. Based on the experiments performed, it was found that a 10% (v/v) solution of the Cyphos IL 101 ionic liquid in toluene allows the extraction of both Pd and Pt with an efficiency of 99% from the initial solution when extraction is carried out at the pH 0.5, vorg:vaq phase ratio 1:1 and contact time of 15 min. Moreover, the research proved that it is possible to separate Pd from Pt at the stripping stage using a 0.1 mol/dm3 thiourea solution while maintaining a high selectivity coefficient.

Non-Dispersive Extraction of Chromium(VI) by Cyphos IL102/Solvesso 100 Using the Pseudo-Emulsion-Based Strip Dispersion Membrane Operation.

The removal of chromium(VI) from an acidic (HCl) medium through non-dispersive extraction with strip dispersion (NDXSD) was investigated using a microporous PVDF membrane support in a permeation cell. The ionic liquid Cyphos IL102 (phosphonium salt) in Solvesso 100 was used as an organic phase. In NDXSD, the stripping phase (NaOH) is dispersed in the organic phase on the cell side with an impeller stirrer adequate to form a strip dispersion. This pseudo-emulsion phase (organic + strip solutions) provides a constant supply of the Cyphos IL102/Solvesso 100 to the membrane phase. Various hydrodynamic and chemical parameters, such as variation in the feed and pseudo-emulsion stirring speeds, HCl and Cr(VI) concentrations in the feed phase, and carrier concentration, were investigated. Results indicated that the best chromium(VI) transport was obtained under the following conditions: feed and pseudo-emulsion stirring speeds of 1000 min-1 and 600 min-1, respectively; an HCl concentration in the feed phase of 0.1 M; a chromium concentration of 0.01 g/L in the same phase; and carrier concentration in the organic phase in the 2-5-10% v/v range. From the experimental data, several mass transfer coefficients were estimated: a bulk diffusion coefficient of 3.1·10-7 cm2/s and a diffusion coefficient of 6.1·10-8 cm2/s in the membrane phase and mass transfer coefficients in the feed (5.7·10-3 cm/s) and membrane phases (2.9·10-6 cm/s). The performance of the present system against other ionic liquids and the presence of base metals in the feed phase were investigated.

Separation of cobalt and nickel from ethylene glycol and glycerol feed solution in chloride media by non-aqueous solvent extraction with Cyphos IL 101

A non-aqueous solvent extraction (NASX) process for the separation of cobalt and nickel from ethylene glycol and glycerol/water feed solutions using the ionic liquid Cyphos IL 101 has been investigated. The use of undiluted Cyphos IL 101 was critically assessed and compared with solvent extraction systems in which toluene, p-cymene, Shellsol A150, and Shellsol GS190 were used as diluents. While the extraction of cobalt(II) chloride from aqueous solution was possible only at high chloride concentrations, extraction percentages of cobalt higher than 80 % were observed from ethylene glycol and glycerol/water feeds containing 0.8 mol·L-1 NaCl. Separation factors over 40,000 for cobalt and nickel could be achieved for extraction with undiluted Cyphos IL 101 from 2.4 mol·L-1 NaCl ethylene glycol and 1.6 mol·L-1 NaCl glycerol feeds. The distribution ratio of cobalt increased with increasing temperatures in both NASX systems. Studies on the mutual solubility showed that Cyphos IL 101 is highly soluble in ethylene glycol at 21 °C (i.e. phosphorus contents up to 432 mg∙L-1), but it turned out that impurities contributed for 400 mg∙L-1 to this value. On the other hand, only 87 mg∙L-1 of Cyphos IL 101 dissolved in glycerol at 21 °C. Finally, a conceptual flowsheet for the separation of cobalt and nickel by NASX is presented, including extraction, stripping, and recovery of the solvents.

Direct Extraction of Platinum Nanoparticles from Fuel Cells with Ionic Liquids: Part 1. Implementation and Optimization of the Process Parameters

The cost of proton-exchange membrane fuel cells (PEMFCs) comes mainly from platinum nanoparticles, which are used as a catalyst; it represents 40% of the stack price for large-scale production. It is thus crucial to reduce their cost to produce cheaper devices, which could compete with fossil energy on the industrial market. One way to reach this goal would be to recover the Pt catalyst from the membrane electrode assembly (MEA) for further recycling. For now, current end-of-life (EoL) technologies are mainly based on hydrometallurgical and pyro-hydrometallurgical processes for recovering platinum, which are identified to be energy-demanding and generate high amounts of toxic liquids and gaseous effluents. To meet sustainability and circular economy criteria in the recycling of noble metals, our approach was based on the use of ionic liquids (ILs) to both extract and stabilize platinum in the form of metallic nanoparticles (Pt NPs), thus avoiding the use of strong acids and the emissions of hydrofluoric acid (HF), which make the waste management of conventional processes complicated. Thirteen different ILs were selected to investigate how their structural composition as well as their physicochemical properties may affect the extent of Pt extraction, and their ability to stabilize detached nanoparticles. This screening study showed that ionic liquids could interact with all of the elements of the active layer and allowed us to delineate the key parameters that ILs should possess to achieve the best extraction performance: hydrophilicity, hydrogen bonding ability, and the coordinating ability of the anions. The best result was obtained with trihexyltetradecylphosphonium chloride (P66614Cl, commercial Cyphos IL 101; 120 °C and 6 h), which not only led to an extraction extent up to >90% of the Pt present initially on the catalytic layer but also allowed in a single step to detach the Pt NPs from the carbon support. The metallic Pt NPs suspended in P66614Cl were found stable with diameters of around 2–3 nm, as evidenced by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) analyses. Compared to conventional processes, this safer and convenient route to recover Pt catalysts from MEAs directly in their metallic form by simple immersion of the electrode in the appropriate IL opens up new perspectives in terms of rare earth metal recycling from material composites.

Recovery of critical metals from spent Li-ion batteries: Sequential leaching, precipitation, and cobalt–nickel separation using Cyphos IL104

This study presents a novel recycling scheme for spent Li-ion batteries that involves the leaching of lithium in hot water followed by the dissolution of all transition metals in HCl solution and their separation using the ionic liquid Cyphos IL104. The parametric studies revealed that >84 % Li was dissolved while the cathode material was leached at 90 °C for 2 h. Approximately 98 % Li from the non-acidic solution was directly precipitated as Li2CO3 at a Li+:CO32− ratio of 1:1.5. The transition metals from the Li-depleted cathode mass were efficiently (>98 %) dissolved in 3.0 mol·L−1 HCl at 90 °C for a 3 h leaching process. Manganese from the chloride leach liquor was selectively precipitated by adding KMnO4 at a 1.25-fold higher quantity than the stoichiometric ratio, pH value 2.0, and temperature 80 °C. The remaining co-existing metals (Ni and Co) were separated from the chloride solution by contacting it with a phosphonium-based ionic liquid at an equilibrium pH value of 5.4 and an organic-to-aqueous phase ratio of 2/3. The loaded ionic liquid was quantitatively stripped in 2.0 mol·L−1 H2SO4 solution, which yielded high-purity CoSO4·xH2O crystals after evaporation of the stripped liquor. Subsequently, ∼99 % nickel was recovered as nickel carbonate [NiCO3·2Ni(OH)2] from the Co-depleted raffinate by the precipitation performed at Ni2+:CO32− ratio of 1:2.5, pH value of 10.8, and temperature of 50 °C. Finally, a process flow with mass and energy balances yielding a high recovery rate of all metals in the exhausted cathode powder of spent LiBs was proposed.

Recovery and Separation of Dysprosium from Waste Neodymium Magnets through Cyphos IL 104 Extraction

In the present study, the extraction of rare earth elements (REEs) from waste neodymium magnets using phosphorus ionic liquid Cyphos IL 104 was investigated. The objective was to recover and separate the heavy REE (Dy) from light REEs (Nd and Pr). Therefore, the experimental parameters of ionic liquid extraction, including contacting time, the initial pH value, extractant concentration, and O/A ratio, have been optimized. The highest separation factor αDy/Nd of 45.18 and αDy/Pr of 47.93 has been achieved. Following the ionic liquid extraction, the comparison of different stripping agents and the stripping parameters (the concentration of stripping agent and A/O ratio) were also explored. In short terms, this research demonstrates the optimal parameters of Cyphos IL 104 for selectively extracting high REE (Dy) and reveals its potential for recovering and separating REEs in real waste.

New method for recovery of nickel and cadmium from the ”black mass” of spent Ni-Cd batteries by solvent extraction

The paper presents experiments with solid–liquid-liquid extraction of heavy metals from the “black mass” (BM) of waste batteries related to the recycling of nickel and cadmium, as well as cobalt (for several samples) from spent Ni-Cd batteries. The extraction and separation of Ni(II) and Cd(II) from the solid BM with Deep Eutectic Solvents (DESs) and other extractants dissolved in toluene or naphtha (kerosene) have been investigated in detail. It has been shown that the extraction efficiency of DESs, contrary to ionic liquids (ILs), is at the level of 30 wt% Ni(II) and 100 wt% Cd(II) from the BM, without the primary process of leaching with sulphuric acid. Solvent extraction has been proposed with two DESs (choline chloride + lactic acid and choline chloride + malonic acid), with ionic liquids (ILs): trihexyltetradecylphosphonium chloride [P6,6,6,14][Cl] (Cyphos IL 101) and trihexyltetradecylphosphonium thiocyanate [P6,6,6,14][SCN], and with organophosphorous-based acids (OPBAs) such as bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). Process factors such as extracting solvents and additives, solvent concentration, holding time, pH and liquid/solid, as well as organic/aqueous (O:A) ratios were studied. For all the systems, the extraction efficiency (E) and the distribution ratio (D) were specified. The metal content in the solid BM was analyzed by the SEM/EDS method and with the use of the UltraWAVE digestion system combined with an atomic absorption spectrometer (FAAS and FAES techniques). An inductively coupled plasma optical emission spectrometer (ICP-OES) was used to determine the concentration of metal ions in aqueous solutions and stripped organic solutions.

An effective process for the separation of U(VI), Th(IV) from rare earth elements by using ionic liquid Cyphos IL 104

Separation and recovery of U(VI) and Th(IV) from rare earth minerals is a very challenging work in rare earth industrial production. In the present study, a homemade membrane emulsification circulation (MEC) extractor was used to separate U(VI) and Th(IV) from rare earth elements by using Cyphos IL 104 as an extractant. Batch experiments were carried out using a constant temperature oscillator to investigate the extraction parameters of the single element and the results indicated that Cyphos IL 104 could reach the extraction equilibrium within 30 min for all the three elements, i.e., U(VI), Th(IV), and Eu(III). Besides, the MEC extractor possessed a strong phase separation ability. The extraction efficiencies of U(VI), Th(IV), La(III), Eu(III) and Yb (III) increased with the increase of pH. La(III), Eu(III) and Yb(III) were hardly extracted when pH ≤ 1.50, which was beneficial for effectively separating U(VI) and Th(IV) from La(III), Eu(III) and Yb(III). In the multi-stages stripping experiments, when the stripping stage number was 3, the effective separation could be achieved by using HCl and H2SO4, since the stripping efficiency reached 80.0% and 100.0% for Th(IV) and U(VI), respectively. Slope method and FT-IR spectra showed that Cyphos IL 104 reacted with U(VI) and Th(IV) by chelation mechanism. The extraction of multi-elements indicated that U(VI) and Th(IV) could be well separated from the solution which contains all rare earth elements, and the extraction efficiencies of U(VI) and Th(IV) both were close to 100.0%. Based on the above experimental results, a flowchart for efficient separation of U(VI) and Th(IV) from rare earth elements was proposed.

Separation of cobalt, lithium and nickel from the “black mass” of waste Li-ion batteries by ionic liquids, DESs and organophosphorous-based acids extraction

New methods of metal extraction from the “black mass” (BM) from spent lithium-ion batteries have been presented with ionic liquids (ILs), Deep Eutectic Solvents (DESs) and organophosphorous-based acids. The low-temperature method of extraction of cobalt, nickel, lithium and other metals without pre-leaching of BM with acids have been proposed in comparison with many methods already described in the literature. Extraction has been studied in detail with ILs: methyltrioctylammonium chloride ([N8,8,8,1][Cl], Aliquat 336), trihexyltetradecylphosphonium chloride ([P6,6,6,14][Cl], Cyphos IL 101), trihexyltetradecylphosphonium thiocyanate ([P6,6,6,14][SCN]), benzethonium tricyanomethanide ([Benzet][TCM]), as well as with DESs mixtures and well known organophosphorous-based acids: bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). It was shown that fast and efficient extraction, with 90–100 wt% recovery of Co(II), may be obtained using DESs. Well known for the extraction of metal ions from the aqueous phase ILs, binary mixtures of ILs (synergistic effect) and Aqueous Biphasic System (ABS) method with NaCl, {[P4,4,4,14][Cl] + NaCl + Co(II)} have shown very low efficiency in the recovery of metals from BM. The extraction of cobalt (30–58 wt%) and the high extraction efficiency of lithium (41–92 wt%) and nickel (37–52 wt%) was obtained using Cyanex 272 in a mixture with diethyl phosphite. Process factors such as solvent content, extraction additivities, stripping and precipitation methods, temperature, holding time, pH and liquid/solid as well as organic/water ratios were studied. For all extractions, the selectivity and distribution ratios were described. A schematic flow chart for the selective recovery of cobalt(II), lithium(I) and nickel(II) from BM has been proposed. The presented extraction processes can compete with the costly hydrometallurgical methods for recovering metals from secondary waste.

Solvent extraction and separation of samarium from transition and rare-earth metals using phosphonium ionic liquid Cyphos IL 104

Solvent extraction and separation of samarium from transition and rare-earth metals using phosphonium ionic liquid Cyphos IL 104

Recovery of zinc and manganese from “black mass” of waste Zn-MnO2 alkaline batteries by solvent extraction technique with ionic liquids, DESs and organophosphorous-based acids

Solvent extraction was used to recover zinc and manganese from the “black mass” (BM) produced in the zinc plant in Poland, the secondary waste from spent zinc-batteries. A lot of methods and extracting solvents such as ionic liquids (ILs), organophosphorous-based acids and Deep Eutectic Solvents (DESs) were investigated. The environmentally friendly method of metal ions extraction without the primary process of waste batteries leaching with sulfuric acid has been proposed. The BM solvent extraction with trihexyltetradecylphosphonium chloride ([P6,6,6,14][Cl], Cyphos IL 101), trihexyltetradecylphosphonium thiocyanate ([P6,6,6,14][SCN]), bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272), and bis-(2-ethylhexyl) phosphoric acid (D2EHPA) has been presented. Process factors and organic to water ratios were studied. A flowchart for zinc and manganese recovery from BM has been presented. The 100 wt% extraction efficiency for Zn(II) was obtained with (Cyanex 272 + diethyl phosphite).Quick and efficient extraction, with 100 wt% recovery of zinc and manganese, was obtained using DES (choline chloride [N2OH,1,1,1][Cl] : lactic acid 1:2, as well as choline chloride [N2OH,1,1,1][Cl] : malonic acid 1:1) with the addition of didecyldimethylammonium chloride surfactant, DDACl. Moreover, the recovery of zinc in the form of a metal deposit was carried out using a potential-control electrolysis from acidic aqueous solutions obtained after extraction with organophosphorous-based acids and diethyl phosphite. For all the systems, the selectivity and distribution ratios have been presented.

Simultaneous Recovery of Precious and Heavy Metal Ions from Waste Electrical and Electronic Equipment (WEEE) Using Polymer Films Containing Cyphos IL 101.

In this article, the application of a polymer film containing the ionic liquid Cyphos IL 101 for the simultaneous recovery of precious and heavy metal ions ((Ni(II), Zn(II), Co(II), Cu(II), Sn(II), Pb(II), Ag(I), Pd(II), and Au(III)) from waste electrical and electronic equipment (WEEE) is described. The experiments were performed for solutions containing metal ions released from computer e-waste due to leaching carried out with concentrated nitric(V) acid and aqua regia. It was found that the applied polymer film allows for the efficient recovery of precious metals (98.9% of gold, 79.3% of silver, and 63.6% of palladium). The recovery of non-ferrous metals (Co, Ni, Cu, Zn, Sn, and Pb) was less efficient (25–40%). Moreover, the results of the performed sorption/desorption processes show that the polymer film with Cyphos IL 101 can be successfully used after regeneration to recover metals ions several times.

Optimization of Green Technique Develop for Europium (III) Extraction by using Phosphonium Ionic Liquid and Central Composite Design Approach

Rare earth compounds widely used in industrial applications and new processes with green solvents are appropriate for recovering these elements. In this study, the ionic liquid application development was investigated to extract europium ions in single and binary systems. A green procedure for europium (III) extraction from aqueous chloride solution was investigated using phosphonium ionic liquid Cyphos IL 104. Comparative conditions were investigated for analyzing better results with the presence of organic extractant such as Cyanex272, D2EHPA in the batch experiments. The experiment design was carried out based on the central composite design principles to analyze the relationships between the responses and the significant parameters. The obtained data revealed that the quadratic equation has good desirability to predict the extraction percentage. Investigation of the extraction process showed that the ionic liquid Cyphos IL104 has selective power in the extraction of europium and the efficiency is higher than the organophosphorus extractants. Accordingly, optimum conditions for maximum removal of europium ions were obtained equal to 5.5, 1, 16 min, and 0.008 M for feed acidity (pH), phase ratio, time, Cyphos IL 104 concentration. Examination of binary systems of rare earth elements showed that ionic liquid had positive and negative effects on the separation factor. The high efficiency of ionic liquid in the reuse condition indicated that the system is appropriate from an economic perspective.

Photodegradation of Phenolic Compounds from Water in the Presence of a Pd-Containing Exhausted Adsorbent

A closed-cycle technology regarding the use of an exhausted Pd-based adsorbent as a photocatalyst in the degradation process of phenol is presented. Pd (II) represents a precious metal of great economic importance. Its obtained from natural sources become more difficult to achieve. Therefore, also considering the regulations of the “circular economy,” its recovery from secondary sources turn out to be a stringent issue in the last years. Pd(II) ions are removed from aqueous solution through adsorption onto Florisil (an inorganic solid support—magnesium silicate) impregnated with Cyphos IL 101 (trihexyl tetradecyl phosphonium chloride). It was observed that the presence of the ionic liquid (IL) in the adsorbent structure doubles the adsorption efficiency of the studied materials. The newly obtained Pd-based photocatalyst was exhaustively characterized and was used in the degradation process of phenol from aqueous solutions. The phenol degradation process was studied in terms of the nature of the photocatalyst used, time of photodegradation and solid: liquid ratio. It was observed that both the presence of IL and Pd lead to an increase in the efficiency of the phenol degradation process. The new Pd-based photocatalyst could be efficiently used in more cycles of phenol photodegradation processes. When is used as a photocatalyst the Florisil impregnated with IL and loaded with 2 mg/g of Pd, a degree of mineralization of 93.75% is obtained after 180 min of irradiation of a phenol solution having a concentration of 20 mg/L and using a solid:liquid ratio = 1:1.

Development of hydrometallurgical process for indium recovery from waste liquid crystal display using Cyphos IL 101

Abstract The main goal of this study was to recover indium from the waste liquid crystal display (LCD) panel. In this context, an ionic liquid Cyphos IL 101 was explored. The extraction parameters such as equilibration period, acid concentration, chloride ion concentration, hydrogen ion concentration were examined on the extraction efficiency of Cyphos IL 101 towards In(III). Quantitative extraction of indium was found at 2.0 mol/L HCl using 0.005 mol/L Cyphos IL 101 and quantitative stripping with 1.0 mol/L H2SO4. Job's method was used to determine the extracted species and R3R‘PInCl4 (R=C6H13; R′=C14H29) was proposed. Based on the observations on multi-metal studies, Cyphos IL 101 was further employed for the removal of indium, tin and copper from the leach liquors of waste LCDs. Optimized conditions were generated for the recovery of indium from waste LCDs. McCabe−Thiele diagram analysis, counter-current extraction and selective stripping were carried out to separate the metal ions, i.e., indium, tin and copper. Two stages at O/A ratio of 1:3 were required for complete removal of tin from the feed and selective stripping of In and Sn was achieved using 0.1 mol/L H2SO4. A scheme for separating indium from the waste LCDs was proposed.

Image analysis data for the study of the reactivity of the phases in Nd-Fe-B magnets etched with HCl-saturated Cyphos IL 101.

Three phases can be distinguished in Nd‒Fe‒B permanent magnets: a Nd2Fe14B matrix grain phase, a Nd-rich grain boundary phase and a Nd-oxide phases. Common reaction models for leaching, such as the shrinking-particle model, cannot simply be applied to composite Nd‒Fe‒B permanent magnets because of the different chemical reactivities of the crystalline phases mentioned above. Etching the surface of a Nd‒Fe‒B magnet to expose its microstructure to electron microscopy is a necessary practice to correlate the microstructure itself to the specific properties of the magnets. Aqueous solutions of mineral acids are often used for etching purposes. However, these solutions are too low viscous to easily control the etching front and they show little selectivity in the etching process. In our work, the ionic liquid Cyphos IL 101 was used to etch bulk magnets instead of aqueous HCl solutions. The bulk Nd‒Fe‒B magnets were first polished, then exposed to a solution of 3 M HCl in Cyphos IL 101 for different times and at different temperatures. Afterwards, the etched Nd‒Fe‒B magnets were washed with ethanol and acetone. The results were examined via scanning-electron microscopy and image analysis. A commercial software, ImageJ®, was employed for image analysis. The latter technique was used to correlate the etched area (%area) or the grain and oxide size to the etching temperature or the etching time. The grain or the oxide size were calculated as Feret diameter. Image analysis revealed to be a necessary tool to support and correct the findings first suggested by the simple scanning-electron microscopy. The data presented in this article might be reused to corroborate a new reactivity order of the three Nd‒Fe‒B phases, different from that traditionally reported in literature, which is – from the most to the least reactive – grain boundary > oxides > the Nd2Fe14B grain phase.

Recovery of Samarium and Cobalt from Sm–Co Magnet Waste Using a Phosphonium Ionic Liquid Cyphos IL 104

Due to outstanding thermal stability and corrosion resistance, samarium–cobalt alloy is being used in rare earth magnet. So, this permanent magnet waste can be a potential source for rare earth metal samarium and critical metal cobalt. Recovery and reuse of Sm, Co from Sm–Co magnet waste can reduce the burden on primary resources and environmental issues related to primary resources. In this work, a hydrometallurgical method for recovery of samarium and cobalt from Sm–Co magnet waste has been developed using an ionic liquid Cyphos IL 104. The optimum separation condition for cobalt and samarium has been determined by varying the concentration of HCl, NaCl, and mixture of HCl and NaCl in the leach liquor. The McCabe–Thiele plot is constructed using 0.075 mol/L Cyphos IL 104. Three counter-current stages at A:O ratio of 1:1.5 are needed for complete extraction of cobalt into the ionic liquid phase leaving samarium in the raffinate. Precipitation stripping of cobalt from the loaded organic is carried out using oxalic acid and the cobalt oxalate, thus formed, is calcined at 450 °C to form Co3O4. The raffinate obtained from the counter-current extraction contains 2.02 g/L Sm and 0.02 mg/L Co. Sm2O3 from raffinate is produced by precipitation of samarium with oxalic acid followed by calcination of samarium oxalate at 800 °C. Both the oxide products are confirmed by XRD.

Separation of adjacent heavy rare earth Lutetium (III) and Ytterbium (III) by task-specific ionic liquid Cyphos IL 104 embedded polymer inclusion membrane

Adjacent rare earth separation has always been one of the hardest separation tasks around world. In this article, a task-specific ionic liquid Cyphos IL 104 embedded polymer inclusion membrane (PIM) was fabricated to realize the adsorption and separation of adjacent heavy rare earth elements Lutetium (III) and Ytterbium (III). Chemical composition of the PIM was verified by attenuated total reflectance Fourier transformed infrared spectroscopy and X-ray photoelectron spectroscopy. And results confirmed only PO and P–O groups participated in the formation of Rare Earth (III)-Cyphos IL 104 complex. A typical thumb-like asymmetric structure was observed by scanning electron microscopy. And the addition of Cyphos IL 104 promoted the hydrophilicity of the PIM as the water contact angle became smaller. Static adsorption and dynamic transport performances were studied in details to get the optimum separation condition. The permeability coefficients of Yb(III) and Lu(III) were 156 μm s−1 and 114.82 μm s−1, respectively; And the initial membrane fluxes were 90.17 μm m−2 s−1 and 65.61 μm m−2 s−1, respectively. The separation factor between Yb(III) and Lu(III) was calculated as 1.37 under the optimized transport condition. All these would provide promising developments of adjacent heavy rare earth separation with an efficient and practical membrane strategy.

Liquid-liquid extraction of cobalt(II) and zinc(II) from aqueous solutions using novel ionic liquids as an extractants

Abstract Extraction efficiencies of Co(II) and Zn(II) from aqueous phase with new ionic liquids (ILs) in comparison with already studied in literature ILs, but without addition of acids and at low temperatures are presented. Thus the new, environmental-friendly method of extraction of metal ions is proposed. A novel ammonium ILs, benzyldimethyloctadecylammonium bis(2,4,4-trimethylpentyl)phosphinate [NBz,1,1,18][BTMPP], didecyldimethylammonium saccharinate, [N10,10,1,1][SACH] and didecyldimethylammonium acesulfamate, [N10,10,1,1][ACE] were synthesized and used between others for this extraction. The solvent extraction behavior was compared to well known in this process ILs: methyltrioctylammonium chloride ([N8,8,8,1][Cl]), Aliquat 336, trihexyltetradecylphosphonium chloride, ([P6,6,6,14][Cl]), Cyphos IL 101 and trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate, ([P6,6,6,14][BTMPP]). Extraction was provided with pure ILs and with addition of complexion agents, such as: 18-crown-6, 24-crown-8, alkanes C24H50, C27H56, Triton TM X-100 and L-histidine. It was shown that quick and efficient extraction, where >90% of Co(II) and Zn(II) may be obtained using pure IL, or with additives, using synergistic effects of mixture of two ILs, or using ILs in Aqueous Biphasic Systems (ABS) method with NaCl at low temperature T = 303 K. The tributyltetradecylphosphonium chloride, [P4,4,4,14][Cl], tetraoctylphosphonium bromide, [P8,8,8,8][Br], and benzalkonium chloride [NBz,1,1,R][Cl] (R = C12H25–60%; C14H29–40%) were used in ABS experiment. The extraction behavior was carried out also using Deep Eutectic Solvents, DES non miscible with water, which presented lower efficiency. The extraction process confirmed the large efficiency and distribution ratio using [P6,6,6,14][BTMPP] with addition of 18-Crown-6 at pH = 7 for Co(II), as well as using Cyphos IL 101 ([P6,6,6,14][Cl]) with addition of 18-crown-6, or Triton TM X-100, or L-histidine at pH 1 (no addition of acid) for Zn(II). The same results for Zn(II) were obtained with ABS method with {[P4,4,4,14][Cl] + NaCl + Zn (II)}. However, the best results were obtained with trihexyltetradecylphosphonium thiocyanate, [P6,6,6,14][SCN] for both metal ions.