Solvent Extraction Of Cobalt Research Articles

Non-aqueous solvent extraction of cobalt and nickel using undiluted ionic liquids in milliflow contacting devices

Non-aqueous solvent extraction at elevated temperatures using undiluted ionic liquids in milliflow contacting devices has been identified as a feasible and alternative approach to accelerate and intensify such critical metal purification and recovery. In the present research, aforementioned principles were applied on the separation of a mixture of cobalt and nickel using two quarternary phosphonium-based extraction systems. For both investigated systems, selectivity towards extraction of cobalt to the extractant was observed. Extraction performance of the system involving EG and Cyphos IL 101 was found to be superior during batch trials. As a result, this system was selected for additional experiments involving the continuous milliflow setup, making it the first application of non-aqueous solvent extraction using ionic liquids in a milliflow reactor. Depending on the processing conditions such as tube diameter (0.08” or 0.04” ID) and flow rate (0.10 mL/min to 6.00 mL/min), different flow regimes and percentages extraction were attained. Best performance in flow was obtained for more elevated temperatures (80 °C and 140 °C) and low flow rates (<0.25 mL/min), as a result of the improved kinetics and advantageous hydrodynamics. Variations of the reactor length to compare residence times under identical flow rates suggest kinetic limitations exist at lower temperatures.

Solvent extraction of cobalt from artificial nickel sulphate solution using PC-88A organic solution as extractant

In this research, an experiment was carried out to separate cobalt from artificial nickel sulfate solution containing cobalt ions by solvent extraction method using organic solvent 2-ethythexyl phosponic acid mono-2-ethylhexyl ester (PC-88A). The experiment was carried out on a laboratory scale. The experimental variables observed included the acidity of the solution (pH), shaking time, shaking speed, and ratio of aqueous and organic (A/O) volume and concentration of PC-88A extractant. The experimental results showed that at pH 6 as much as 95.68% of cobalt could be extracted with the PC-88A.

Solvent extraction of cobalt from spent lithium-ion batteries: Dynamic optimization of the number of extraction stages using factorial design of experiments and response surface methodology

The optimization of lithium-ion batteries (LiBs) recycling is crucial not only from a waste management perspective but also to decrease the dependence on imports of critical raw materials. In addition, the diversification of the recycling technologies is very important for better flexibility of the market. This study aims at investigating the recovery of Co from spent LiBs using solvent extraction from a real chloride-based solution obtained after the removal of Mn, which is very rarely reported. Cyanex 272 was used as the extractant and the effect of several variables on the extraction efficiency was considered to model and optimize the separation of Co and Ni. The number of extraction stages directly affects not only the process efficiency but also its cost. Thus, in this work, a novel approach was developed to assist in the selection of the number of extraction stages using a dynamic method based on the factorial design of experiments and response surface methodology combined with the Kremseŕs Equation. This method can assist the process design, decrease the overall cost of the operation, and optimize the separation of Co and Ni in a reduced number of extraction stages. The concentration of Co and Ni in the feed solutions is ∼ 8.3 g/L and 1.9 g/L, respectively. Based on the results, 98% extraction efficiency for Co can be achieved in 1 to 2 extraction stages with low co-extraction of Ni (<5%) when using 0.6–0.8 M Cyanex 272, O:A ratio below 1 and pH ∼ 5, but several combinations of conditions could provide similar results.

Thermodynamic Modeling of Salting Effects in Solvent Extraction of Cobalt(II) from Chloride Media by the Basic Extractant Methyltrioctylammonium Chloride.

The design and optimization of solvent extraction processes for metal separations are challenging tasks due to the large number of adjustable parameters. A quantitative predictive solvent extraction model could help to determine the optimal parameters for solvent extraction flow sheets, but such predictive models are not available yet. The main difficulties for such models are the large deviations from ideal thermodynamic behavior in both the aqueous and organic phases due to high solute concentrations. We constructed a molecular thermodynamic model for the extraction of CoCl2 from different chloride salts by 0.2 mol L–1 trioctylmethylammonium chloride in toluene using the OLI mixed-solvent electrolyte (OLI-MSE) framework. This was accomplished by analyzing the water and hydrochloric acid content of the organic phase, measuring the water activity of the system, and using metal complex speciation and solvent extraction data. The full extractant concentration range cannot be modeled by the OLI-MSE framework as this framework lacks a description for reversed micelle formation. Nevertheless, salting effects and the behavior of hydrochloric acid can be accurately described with the presented extraction model, without determining specific Co(II)–salt cation interaction parameters. The resulting model shows that the salting effects originate from indirect salt cation–solvent interactions that influence the availability of water in the aqueous and organic phases.

Continuous microfluidic solvent extraction of cobalt from mimicked and real asteroid leaching solutions

This research proposes a pathway for the last step of the asteroid mining process: the purification of the adjacent metals, cobalt and nickel, in the frame of in-situ resource utilization (ISRU) in space. Major technological and economic challenges will need to be overcome, and one main issue to be tackled is the reduction of water usage in this process. Therefore, the leached metal solutions are expected to contain ultra-high metal concentrations, up to 10 mol/l. These solutions will have challenging thermodynamic properties (increased density, viscosity and interfacial tension). As a result, an analysis of dimensionless numbers for fluidics and mass transport was made, showing that some of these are favourable under the constraints of accessible microfluidic operations. Experiments were performed with advanced microfluidic reactors (a coiled-flow inverter (CFI) and an industrial re-entrance flow reactor from Corning®) at high metal concentrations and high nickel to cobalt ratios (3:0.3 mol/l Ni:Co). Using Cyanex 272 as a selective extractant for cobalt, extraction efficiencies of 60% with high separation factors (>1000) were reached in just one extraction stage. The CFI showed high extraction efficiency for low fluid velocities and a residence time of 60 s. For the Corning® reactor, high fluid velocities or the use of many modules (>3) are needed to obtain an emulsion, resulting in high extraction efficiencies at a very short residence time of 13 s. The comparison between the CFI and the Corning® reactor shows that they share the best operation point (at 120 ml/h), but the Corning® reactor performs better at higher flow rates and thus can leverage higher productivity. However, the CFI is easier to operate and has a much lower pressure drop, resulting in low energy input. Finally, an iron meteorite sample was leached and efficiently extracted in both microfluidic reactors.

Solvent Extraction of Cobalt (II) with 2, 6-dithiolphenol and its Derivatives in the Presence of Hydrophobic Amines

Mixed-ligand complexes of Cobalt(II) with dithiolphenol (DP) {2, 6-dithiolphenol (DTP) and its derivatives (2, 6-dithiol-4-methylphenol (DTMP), 2, 6-dithiol-4-propylphenol (DTPP), 2, 6-dithiol-4-tert-buthylphenol (DTBP)} in the presence of aminophenols (AP) have been studied by spectrophotometry. Extraction of mixed ligand complexes is maximal at pH 4.1-6.5. The optimal conditions for the formation and extraction of mixed-ligand compounds have been found and the ratios of components I the complexes have been determined. The Beer’s law was applicable in the range of 0.2-20 μg/ml. The effect of foreign ions and reagents on the extraction was studied. The method is free from common interferences. A procedure has been developed for extraction – spectroand#172;photometric determination cobalt in different objects (in steel, sewage water, bottom sediments, food and soil samples).

Liquid-liquid extraction of Co(II) from nitrate solution using TOA

Cobalt has widespread industrial applications but if present in excess amounts it may cause several noxious effects. Liquid-liquid extraction process can be useful in cleaning the environment from harmful chemical pollutants. Solvent extraction of cobalt using cobalt nitrate as the feed solution and trioctylamine (TOA) as the extractant in toluene was carried out where the effects of nitric acid concentration, equilibration time, concentration of the extractant and cobalt ions had been investigated. The percentage extraction of Co(II) decreased upon increasing the concentration of acid. A time of 15 min was needed to achieve the extraction equilibrium. Highest percentage extraction of cobalt was achieved using 0.1 M TOA which is 99%. Cobalt loading increased with increase in metal ion concentration. Presence of nitrate ions had almost no significance in the extraction process. The loaded organic phase was stripped using different stripping agents and 99.15% back extraction was achieved with 0.1 mol/L (NH4)2CO3. The extraction mechanism was proposed from the FTIR and slope measurement.

Solvent Extraction of Cobalt (II) with 2, 6-dithiolphenol and its Derivatives in the Presence of Hydrophobic Amines

Mixed-ligand complexes of Cobalt(II) with dithiolphenol (DP) {2, 6-dithiolphenol (DTP) and its derivatives (2, 6-dithiol-4-methylphenol (DTMP), 2, 6-dithiol-4-propylphenol (DTPP), 2, 6-dithiol-4-tert-buthylphenol (DTBP)} in the presence of aminophenols (AP) have been studied by spectrophotometry. Extraction of mixed ligand complexes is maximal at pH 4.1-6.5. The optimal conditions for the formation and extraction of mixed-ligand compounds have been found and the ratios of components I the complexes have been determined. The Beer’s law was applicable in the range of 0.2-20 μg/ml. The effect of foreign ions and reagents on the extraction was studied. The method is free from common interferences. A procedure has been developed for extraction – spectroand#172;photometric determination cobalt in different objects (in steel, sewage water, bottom sediments, food and soil samples).

Methyl-isobutyl ketone and 1-octanol as synergistic agents and phase modifiers in solvent extraction of cobalt(II) by the N-(2-hydroxybenzylidene)aniline from sulfate medium

The synergistic solvent extraction of cobalt(II) from sulfate medium with N-(2-hydroxybenzylidene) aniline in association of two synergistic agents, the methyl-isobutyl ketone (MIBK) and 1-octanolin chloroform at 25 °C, has been studied. Synergistic and antagonistic effects are observed for the title metal at low and high concentration ratios of the synergistic agents. The synergistic extraction of cobalt(II) with the mixtures has been investigated with the methods of slope analysis. The extracted species with the mixtures are CoL2(S)2 and CoL2 (HL) (S) (L, denoted N-(2-hydroxybenzylidene) aniline ion and S denoted MIBK or 1-octanol).

Improvement of magnetic solvent extraction using functionalized silica-coated Fe3O4 nanoparticles

The application of hydrophobic magnetic nanoparticles functionalized with long carbon chain molecules, such as oleic acid, in the solvent extraction process results in a faster phase disengagement and does not affect the extraction and stripping percentages of cobalt with Cyanex 272, as has been reported in previous studies. However, the chemical stability of this organic phase is limited by its applicability only in contact with aqueous solutions of pH ≥ 2.0. Aiming to overcome such an operational constraint, this study proposed the use of nanoparticles coated with silica and functionalized with a long carbon-chain silane (OTS) in the solvent extraction process. Due to the silica-layer coating of the magnetic core of magnetite and maghemite, such nanoparticles became stable when in contact with aqueous solutions of high acidity of up to 2 mol/L. The proposed nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and magnetic analysis. Their effect on the solvent extraction of cobalt with Cyanex 272 was investigated using magnetic fluids with different concentrations (0, 10, 20, and 30 g/L of magnetic nanoparticles). It was also observed that, under the conditions studied in this work, the presence of these magnetic nanoparticles did not interfere in the efficiency of metal extraction and stripping. Moreover, the time for the phase disengagement can be reduced by a factor of 25 when compared to the process without magnetic nanoparticles.

Phase separation in solvent extraction of cobalt from acidic sulfate solution using synergistic mixture containing dinonylnaphthalene sulfonic acid and 2-ethylhexyl 4-pyridinecarboxylate ester

Abstract Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).

Counter-current separation of cobalt(II)–nickel(II) from aqueous sulphate media with a mixture of Primene JMT-Versatic 10 diluted in kerosene

ABSTRACTThis work claims the use of the mixture of Primene®JMT-Versatic 10 [HJMT+·Versatic−] IL diluted in Kerosene as an extractant for cobalt/nickel separation from sulphate media by solvent extraction technique, its application on a continuous counter-current device is possible because the presence of Primene®JMT in the organic phase allows us to maintain the pH of the equilibrated aqueous phase at an almost stable value. The solvent extraction of cobalt and nickel ions is studied as a function of the extractant concentration in the organic phase and the concentration of both metals. By constructing the McCabe–Thiele diagram, we found that four steps are necessary to separate the cobalt(II) from the nickel(II) in sulphate media. A simulated continuous counter-current experiment corroborated the McCabe–Thiele predictions, obtaining a raffinate containing 83% of the inlet nickel with a purity of 99.9%, working with an A:O ratio 1:2.

Solvent Effect on the Extraction of Cobalt(II) Using Bis(2-ethylhexyl) Phosphoric Acid

The solvent extraction of cobalt(II) from sulfate medium using bis(2-ethylhexy1) phosphoric acid has been investigated. The influence of the following parameters was studied: the equilibrium pH, the concentration of the extractant and the nature of diluent. Influence of diluent using several polar solvents as diluents in addition to non-polar solvents in the extraction of cobalt(II) is discussed. The extractable species has been identified as CoL2 in 1-octanol and methyl isobutyl ketone and CoL2.2HL in toluene, dichloromethane, chloroform, carbon tetrachloride and cyclohexane. Equilibrium formulations were determined for various diluents.

Extraction liquide-liquide du cobalt(II) par la N-(2-hydroxybenzylidene) aniline

The liquid–liquid extraction of cobalt(II) from sulfate medium with N-(2- hydroxybenzylidene)aniline is studied with the following parameters: pH, concentration of the extractant and the nature of diluent. The solvent extraction of cobalt(II) in different diluents leads to third phase formation. The stoichiometry coefficients of the extracted complexes are determined by the slope analysis method. The extaction constants are evaluated for the different diluents. The extraction is better in the following order: cyclohexane &gt; toluene &gt; chloroform.

Cobalt electrowinning – A systematic investigation for high quality electrolytic cobalt production

The process of Minera y Metalúrgica del Boleo recovers cobalt from a complex oxide and sulfide ore by solvent extraction and electrowinning after the recovery of copper and zinc (as copper cathode and zinc sulfate monohydrate). As part of the process development, cobalt electrowinning was systematically studied with respect to temperature, pH, pitting behavior, deposit morphology, deposition stress and interfacial tension. Electrowinning test work was conducted in a bench scale diaphragm cell in a sulfate medium with control of the catholyte pH. Cobalt was deposited on a coated stainless-steel mandrel cathode with exposed circles to allow plating of disk shaped deposits over the surface of the cathode that could be easily stripped after 5–7 days of deposition. Limiting the area of plating prevents the detachment of the cobalt deposit from the cathode due to high deposition stress. The morphology and pitting behaviour varied for different commercial cobalt raw materials used for making cobalt sulfate solution as they contained different impurities or additives. The deposition behaviour changed after the solutions had an activation carbon treatment as some impurities (mainly organic compounds) were removed. In the temperature range from 50 to 65 °C, a higher temperature resulted in a brighter deposit with more pits and smaller lateral dendrites. The cobalt deposition current efficiency was around 98% at pH 3.0 and was not sensitive to temperature. With decreasing catholyte pH from 3.5 to 2.0, the cobalt current efficiency decreased from 99 to 88% and the growth of lateral dendrites were significantly suppressed. The formation of pits resulted from the adhesion of hydrogen bubbles on the cobalt deposit. The adhesion of hydrogen bubbles was determined by the prevailing surface and interfacial tensions. Anti-pitting agents were used to change the interfacial and surface tensions in such a way that the detachment of bubbles was facilitated, resulting in a pit-free cobalt deposit. The anti-pitting agents affected the deposit morphology and internal stress. The impact of the anti-pitting agents on the disengagement of organic and aqueous phases during cobalt solvent extraction was also investigated. The internal stress of the cobalt deposit as a function of temperature and anti-pitting agent dosage and the conductivities of the CoSO4-Na2SO4-H2SO4 system are reported.

Synergistic Extraction Study of Cobalt (II) by Mixtures of Capric Acid and Tri-n-octylphosphine Oxide (TOPO)

The synergistic solvent extraction of cobalt (II) from sulfate aqueous solutions with capric acid (HL) and tri-n-octylphosphine oxide (TOPO) intochloroform, has been studied. The experimental data for the capric acid alone reveal the self-adduct formation CoL2(HL)2, in the organic phase. A remarkable enhancement on the extraction of cobalt (II) with capric acid was observed upon the addition TOPO. The synergistic enhancement was ascribed to the adduct formation CoL2(HL)2 n(TOPO) (n= 1 or 2). The TOPO-HL interaction strongly influences the synergistic extraction efficiency. The value of the partition, dimerization and equilibrium constants were determined.

Effects of structural changes of new organophosphorus cationic exchangers on a solvent extraction of cobalt, nickel and manganese from acidic chloride media

The effects of structural changes of organophosphorus cationic exchangers on metal-distribution curves (extraction efficiency vs. pH) have been investigated for the recovery of cobalt(ii), nickel(ii) and manganese(ii) from acidic chloride solutions.

Solvent extraction of cobalt and nickel from chloride solution by mixtures of acidic organophosphorous extractants and amines

In order to extract Co and Ni from the chloride solution with low initial pH (1–3), solvent extraction experiments were performed by employing the mixture of organophosphorous extractants (D2EHPA, PC 88A and Cyanex 272) and amine extractants (Alamine 336, Alamine 308, and Alamine 300). Among the studied mixtures, a mixture of Alamine 308 and Cyanex 272 showed the best efficiency for the selective extraction of Co (63%) over Ni from chloride solutions with an equilibrium pH of 4.9. Although Co was not extracted by each single extractant, the synergism was observed for Co extraction using this mixture. Moreover, it was possible to selectively extract Co over Ni using the mixture of Alamine 308 and Cyanex 272.

SYNERGISTIC SOLVENT EXTRACTION OF Co(II) AND Li(I) FROM AQUEOUS CHLORIDE SOLUTIONS WITH MIXTURE OF CYANEX 272 AND TBP

In this work, separation of cobalt(II) over lithium(I) ions from aqueous chloride solutions by synergistic solvent extraction (SX) has been studied. A synergistic mixture of commercial extractants such as bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) and tributyl phosphate (TBP) in kerosene was used as a selective extractant. The investigations were first performed to select optimal conditions for the effective separation including pH of the aqueous phase as well as concentration of synergistic mixture. High selective solvent extraction of cobalt(II) over lithium(I) from chloride solution has been achieved by the mixture of 0.1 M Cyanex 272 and 0.05 M TBP in kerosene while efficient Co(II) stripping has been performed by 0.5 M sulphuric acid.

Study of synergic effect of trioctyl phosphine oxide on the solvent extraction of cobalt(II)-TT A complex

Study of synergic effect of trioctyl phosphine oxide on the solvent extraction of cobalt(II)-TT A complex