Separation Of Transition Metals Research Articles

Separation of lithium and transition metals from leachate of spent lithium-ion batteries by solvent extraction method with Versatic 10

When extracting metals from the leaching liquor of spent lithium-ion batteries (LIBs), the focus of traditional methods has been putting on the separation of transition metals, i.e. manganese, cobalt and nickel, which needs a long treatment process and causes significant loss of lithium. In this study, a simple and efficient process consisting of co-extraction of transition metals with neodecanoic acid (Versatic 10) and recovery of lithium by carbonate precipitation is developed. Firstly, the extraction mechanism of Versatic 10 is explored by slope analysis. And the results show that Versatic 10 has better selectivity to nickel and cobalt than to manganese, and it hardly extracts lithium. Then, practical experiments on solvent extraction conditions are carried out. The total extraction efficiencies of nickel, manganese and cobalt, after two stages of extraction, reach 99.18%, 97.05% and 98.47%, respectively. The experimental results are consistent with the theoretical analysis results. Finally, lithium is recovered by Na2CO3 precipitation. The purity of recovered lithium carbonate is high up to 99.61%. By using this process, the obtained solution of nickel, manganese and cobalt can be directly used to prepare ternary material precursor, and only 8% of lithium is lost.

Separation of transition metals from rare earths by non-aqueous solvent extraction from ethylene glycol solutions using Aliquat 336

Abstract Solvent extraction is a widely used separation technique in extractive metallurgy. A conventional solvent extraction system consists of an aqueous phase and an immiscible organic phase. In this work, we show that replacement of water by a polar organic solvent can lead to superior metal separations. Cobalt(II) and samarium(III) chlorides dissolved in water and ethylene glycol (EG), respectively, with LiCl as chloride source, were extracted by Aliquat 336 diluted in toluene. Both cobalt and samarium were extracted from the aqueous solutions, but cobalt was extracted more efficiently from the ethylene glycol solutions than from the aqueous solutions, whereas samarium was not extracted at all from the ethylene glycol solutions. As a result, cobalt and samarium could be separated completely in a single extraction step from ethylene glycol solutions. The mechanisms of cobalt extraction by Aliquat 336 from the ethylene glycol and aqueous solutions were found to be similar, as validated by slope analysis and UV–VIS absorption spectroscopy. Samarium was extracted from the aqueous solution through the salting-out effect of LiCl. Interestingly, LiCl has a much lower salting-out effect for samarium in ethylene glycol than in water due to the lower dielectric constant of ethylene glycol and the lower solubility of LiCl in ethylene glycol. Consequently, samarium is not salted out from ethylene glycol, leading to a very efficient separation of cobalt and samarium. This separation effect can also be applied to the separation of other transition metal and rare-earth metal pairs, including iron/neodymium and zinc/europium.

Separation of transition metals and chelated complexes in wastewaters

This review responds to the ongoing needs of wastewater engineers tasked with treating aqueous solutions containing chelated complexes of metal ions, of which nickel citrate in electrodeless plating and copper–EDTA in electronic chip board manufacturing are two key examples. Because of the presence of these sequestering agents, metallic ions cannot be readily precipitated by alkalinity, making a compelling case for the discovery of alternative methods of treatment. This review is a critical appraisal of the varying degrees of success in separation process strategies deployed for the recovery of metallic ions under such challenging chemical conditions. Guidance is provided on making progress toward satisfactory industrial solutions to surmount these difficulties. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 761–783, 2015

Separation of transition metals on a poly-iminodiacetic acid grafted polymeric resin column with post-column reaction detection utilising a paired emitter–detector diode system

The selectivity, retention and separation of transition metals on a short (2 mm × 50 mm) column packed with a poly-iminodiacetic acid functionalised polymer 10 μm resin (Dionex ProPac IMAC-10 ®) are presented. This stationary phase, typically used for the separation of proteins, is composed of long chain poly-iminodiacetic acid groups grafted to a hydrophilic layer surrounding a 10 μm polymeric bead. Through the use of a combination of a multi-step pH and picolinic acid gradient, the separation of magnesium, iron, cobalt, cadmium, zinc, lead and copper was possible, followed by post-column reaction with 4-(2-pyridylazo) resorcinol (PAR) and absorbance detection at 510 nm using a novel and inexpensive optical detector, comprised of two light emitting diodes with one acting as a light source and the other as a detector. Column efficiency for selective transition metals was in excess of N = 10,000, with the baseline separation of seven metal cations in <3 min possible under optimised conditions. Detection limits of between 5 and 81 μg/L were possible based upon a 50 μL injection volume.

Silanation of Nanostructured Mesoporous Magnetic Particles for Heavy Metal Recovery

Nanostructured mesoporous magnetic (m-Fe3O4) particles are promising candidate materials for separation, detoxification, and precious metal recovery. The silanation of m-Fe3O4 particles using 3-aminopropyltriethoxysilane is described. The silanized films were characterized using XPS, diffuse-reflectance FTIR spectroscopy, and electrokinetic techniques. The loading capacity of the silanized m-Fe3O4 particles was found to be superior to that of m-Fe3O4 or directly silanized Fe3O4 particles. Extraction and separation of transition metals (II) were investigated using the silanized m-Fe3O4 particles. The effectiveness of metal (II) extraction was found to increase with increasing solution pH, but was less effective at pH below 2. Satisfactory separation with loading efficiency in the order of Cu2+ > Ni2+ > Zn2+ was obtained. The adsorbed metals were successfully desorbed with 1 M aqueous HCl solutions. As a result, the recovered m-Fe3O4 particles can be recycled in industrial applications.

Sorption of transition metals on monolith CIM discs modified with oligoethyleneamines

The immobilization of oligoethyleneamines on the surface of commonly used sorbents imparts complexing properties to them. The simultaneous preconcentration and separation of transition metals in a chromatofocusing mode can be performed on these sorbents. A considerable disadvantage of this method is the duration of separation, which requires 2 to 3 h. A decrease in the analysis time requires the use of fundamentally new sorption materials and chromatographic columns based on them.

Separation of Transition Metals Using Inorganic Adsorbents Modified with Chelating Ligands

The extraction and separation of transition metals has been investigated using several inorganic adsorbents (silica gel, MCM-41, and aluminum oxide), modified with ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) as chelating ligands. The metal ions in aqueous solution were coordinated successfully by the ligands on the surface of the adsorbents under moderate conditions. Metal−ligand complexes formed on the adsorbents effectively in the region of low pH (1−2) but scarcely formed at pH > 4. Silica gel modified with EDTA (silicaED) was shown to be the most effective adsorbent for the extraction of metals and to form specific metal−EDTA complexes, with stability constants lying in the order Cu2+ > Ni2+ > VO2+ > Zn2+ > Co2+ > Mn2+. The relatively good separation of these six adjacent metals was therefore also carried out using the silicaED. The metals coordinated on the silicaED could be desorbed completely by putting the material into contact with 1 mol/L aqueous HCl solution, such that the silicaED recovered could be reused for further separation.

Separation of Transition Metals with Poly(pyrazolyl)borates by Solvent Extraction Technique

Separation of Transition Metals with Poly(pyrazolyl)borates by Solvent Extraction Technique

Separation of some cations from aqueous solutions using a liquid emulsion membrane

A liquid emulsion membrane (LEM) was evaluated for the separation of some transition metal ions, particularly ferric ion. The effect of parameters such as composition of membrane phases, pH of source phase, temperature, number of fractions, treatment ratio, stirring time and speed and time for waiting separation of source and LEM phases were studied. Recoveries of the cations were found to be 84 ± 4%, 91 ± 1%, 89 ± 4%, 95 ± 2% and 86 ± 4% for Fe(III), Mn(II), Ni(II), Cu(II) and Zn(II), respectively, at 90% confidence level. The effect of excess amount of Ca(II) and Mg(II) on the separation of transition metals have also been investigated. Ion concentrations were measured by flame atomic absorption spectrometry and by titration.

The Applicability of Chromatofocusing to the Concentration and Separation of Transition Metals with Tetraethylenepentamine-bonded Silica

A new approach to the separation of metals is possible owing to a combination of the buffering and complexing properties of silica gel with immobilized tetraethylenepentamine molecules.

Analytical Separation of Copper(II), Cobalt(II) and Nickel(II) Using Polymer Bound Anthrantic Acid

Abstract The preferential complexing tendency of different nietal ions towards chelating agents anchored on a polymer has been used for separation of transition metals. the anthranilic acid group was anchored on the polymeric cellulose back-bone by successive coupling with trifunctional reagent cyanuric chloride, in diozane medium, at pH 7 and 9–10, respectively. This polymer bound chelating agent was used to separate copper(II), nickel(II) and cobalt(II) in the concentration range 1.0–0.1 mmol/L. the separation of a mixture of two components was quantitative using column chromatography.

Synthetic Inorganic Ion-Exchange Materials. XXII. Distribution Coefficients and Possible Separation of Transition Metals on Crystalline Antimonic(V) Acid as a Cation-Exchanger

Abstract Cation-exchange distribution coefficients with crystalline antimonic(V) acid (C-SbA) are presented for the transition metals in nitric acid solution at different concentrations. The affinity series (Ni2+ < Mn2+ < Zn2+ < Co2+ < Cu2+ << Cd2+) was found for microquantities of the transition metals. On the basis of the distribution coefficients, the effective separation of Ni2+ or Cd2+ from Zn2+ and Cu2+ has been achieved with a small column (2.0 ± 0.4 cm i.d.) of the C-SbA.