Removal of lithium from aqueous solutions by precipitation with sodium and choline alkanoate soaps.

In order to comply with the expected tightening of discharge limits for lithium to surface waters, the lithium-ion battery industry will need access to methods to reduce the concentration of lithium in wastewater down to ppm levels. In this Communication, we discuss the possibility of using sodium and choline soaps as precipitating agents for lithium, comparing the two soap classes and probing the influence of the carbon chain length. It was found that lithium concentrations down to 10 ppm can be reached with sodium stearate, and down to 1 ppm with choline stearate, using a slight excess of the precipitating agent.

Selective extraction of lithium over alkali and alkaline earth ions by synergistic solvent extraction.

Direct lithium extraction (DLE) from natural surface and geothermal brines is very challenging due to the low ratio of lithium to other metals, and the lack of suitable materials that bind lithium with sufficiently high selectivity. In this paper, a synergistic solvent extraction system is described that comprises a liquid ion exchanger (saponified bis(2-ethylhexyl)dithiophosphoric acid) and a lithium-selective ligand (2,9-dibutyl-1,10-phenanthroline) in an aliphatic diluent. The extraction mechanism was investigated and was confirmed to involve the binding of lithium to the selective ligand, while the liquid ion exchanger facilitates the transfer of metal ions from the aqueous to the organic phase.

A Preliminary Study of Spherical Surface-Modified Carbon Materials for Potential Application in La (Ac) and Bi Separation.

Separation of high-activity Bi from Ac for targeted alpha therapy is challenging due to the instability of existing sorbents. Surface-modified carbon materials have shown promise for use in inverse Ac/Bi generators. However, previously reported materials with irregular shapes may limit their applications in column separations.

Improving Americium/Curium Separation Factors in the AmSel Process through Symmetry Lowering of the Diglycolamide Extractant.

Partitioning and transmutation are important strategies for closing the nuclear fuel cycle. The diglycolamide extractant TODGA has played a major role in the development of solvent extraction processes for nuclear fuel reprocessing due to its good extraction performance, its hydrolytic and radiolytic stability, and its compliance with the CHON principle. However, due to drawbacks such as the tendency to form a third phase during extraction if no phase modifiers are used, continued research on diglycolamide-type extractants has led to the development of diglycolamides with decreased symmetry.

Carbon Dioxide as a Sustainable Reagent in Circular Hydrometallurgy.

This review highlights the use of CO as a reagent in hydrometallurgy, with emphasis on the new concept of circular hydrometallurgy. It is shown how waste CO can be utilised in hydrometallurgical operations for pH control or regeneration of acids for leaching. Metal-rich raffinate solutions generated after removal of the valuable metals can serve as feedstocks for mineral carbonation, providing alternative avenues for CO sequestration.

Methanesulfonic acid (MSA) in clean processes and applications: a tutorial review.

This Tutorial Review acquaints chemists and metallurgists with the properties and industrial applications of methanesulfonic acid (MSA, CHSOH). Over the past quarter-century, MSA has garnered increasing interest as a reagent for green chemistry due to its strong acidity, while circumventing many of the challenges associated with handling concentrated sulfuric acid, hydrochloric acid, or nitric acid. Concentrated MSA is a non-oxidizing reagent, exhibiting high chemical stability against redox reactions and hydrolysis, as well as high thermal stability and limited corrosivity towards construction materials.

Recycling of metals from LiFePO battery cathode material by using ionic liquid based-aqueous biphasic systems.

Lithium-ion batteries are essential for electric vehicles and energy storage devices. With the increasing demand for their production and the concomitant surge in waste generation, the need for an efficient and environmentally friendly recycling process has become imperative. This work presents a new approach for recycling of metals from the LiFePO (LFP) cathode material.

Separation of americium from highly active raffinates by an innovative variant of the AmSel process based on the ionic liquid Aliquat-336 nitrate.

A new variant of the AmSel (Americium Selective Separation) system for the separation of Am(iii) from a PUREX raffinate was tested in which the aliphatic diluent was replaced by the ionic liquid Aliquat-336 nitrate. For this ionic liquid variant, the kinetics, and the influence of both the HNO concentration and the ligand concentration on the stripping were evaluated. In addition, both the original AmSel system, and the ionic liquid variant were demonstrated on a simulated highly active raffinate.

Gamma radiation effects on AG MP-50 cation exchange resin and sulfonated activated carbon for bismuth-213 separation.

Medical Ac/Bi radionuclide generators are designed to provide a local supply of the short-lived Bi for cancer treatment. However, radiation-induced damage to the sorbents commonly used in such radionuclide generators remains a major concern. In this study, the effects of gamma radiation on AG MP-50 cation exchange resin and sulfonated activated carbon (SAC) were studied by analyzing the changes in the morphological characteristics, functional groups, and the La/Bi sorption performance, with La being a suitable non-radioactive substitute for Ac.

Scalable Electrodeposition of Liquid Metal from an Acetonitrile-Based Electrolyte for Highly Integrated Stretchable Electronics.

The advancement of highly integrated stretchable electronics requires the development of scalable sub-micrometer conductor patterning. Eutectic gallium indium (EGaIn) is an attractive conductor for stretchable electronics, as its liquid metallic character grants it high electrical conductivity upon deformation. However, its high surface tension makes its patterning with sub-micrometer resolution challenging.

Fluorine-free organic electrolytes for the stable electrodeposition of neodymium metal.

Electrowinning is regarded as a clean process to recover neodymium metal from secondary sources such as spent Nd-Fe-B permanent magnets, but the current methods are severely limited by a high energy consumption (molten salts), or by the high costs and environmental impact of the electrolyte components (ionic liquids). Therefore, there is a demand for more sustainable electrowinning methods for the recovery of neodymium metal. Inspired by our own previous work and the work of others, we developed new fluorine-free organic electrolytes that enable the electrodeposition of neodymium metal at room temperature.

Removal of copper and iron from ethanolic solutions by an anion exchange resin and its implication to rare-earth magnet recycling.

In the recycling of end-of-life rare-earth magnets, the recovery of non-rare earth constituents is often neglected. In the present study, strong cation and anion exchange resins were tested batchwise for the recovery of the non-rare-earth constituents of permanent magnets (copper, cobalt, manganese, nickel and iron) from synthetic aqueous and ethanolic solutions. The cation exchange resin recovered most of metal ions from aqueous and ethanolic feeds, whereas the anion exchange resin could selectively recover copper and iron from ethanolic feeds.

Conversion of Lithium Chloride into Lithium Hydroxide by Solvent Extraction.

Unlabelled: A hydrometallurgical process is described for conversion of an aqueous solution of lithium chloride into an aqueous solution of lithium hydroxide via a chloride/hydroxide anion exchange reaction by solvent extraction. The organic phase comprises a quaternary ammonium chloride and a hydrophobic phenol in a diluent. The best results were observed for a mixture of the quaternary ammonium chloride Aliquat 336 and 2,6-di--butylphenol (1:1 molar ratio) in the aliphatic diluent Shellsol D70.

Choline chloride-ethylene glycol based deep-eutectic solvents as lixiviants for cobalt recovery from lithium-ion battery cathode materials: are these solvents really green in high-temperature processes?

Deep-eutectic solvents (DESs) are often considered to be safe, eco-friendly and non-toxic solvents. Due to these green credentials, they are increasingly being studied for application in metal recycling processes. One example is their use as lixiviants for the recovery of cobalt from lithium cobalt oxide (LiCoO, LCO), which is a common cathode material in lithium-ion batteries.

Recovery of copper, zinc and lead from photovoltaic panel residue.

The increase in photovoltaic panel installations in Europe will generate vast amounts of waste in the near future. Therefore, it is important to develop new technologies that allow the recycling of end-of-life photovoltaic panels. This material can serve as a secondary resource, not only for precious metals ( silver), but also for base metals.

Dissolution behavior of precious metals and selective palladium leaching from spent automotive catalysts by trihalide ionic liquids.

The dissolution behavior of the precious metals gold, platinum, rhodium and palladium in the trihexyl(tetradecyl)phosphonium trihalide ionic liquids [P][Cl], [P][Br], [P][IBr] and [P][I] was investigated. The highest dissolution rates were observed for the trichloride ionic liquid [P][Cl] and this system was investigated in more detail. The effects of the trichloride concentration in the ionic liquid and temperature were studied, reaching higher leaching rates at higher trichloride conversions and increased temperatures.

Continuous Counter-Current Ionic Liquid Metathesis in Mixer-Settlers: Efficiency Analysis and Comparison with Batch Operation.

Following the initial cation formation, the synthesis of ionic liquids (ILs) often involves an anion-exchange or metathesis reaction. For hydrophobic ILs, this is generally performed through several cross-current contacts of the IL with a fresh salt solution of the desired anion. However, if a large number of contacts is required to attain an adequate conversion, this procedure is not economical because of the large excess of the reagent that is consumed.

Nonaqueous Solvent Extraction for Enhanced Metal Separations: Concept, Systems, and Mechanisms.

Efficient and sustainable separation of metals is gaining increasing attention, because of the essential roles of many metals in sustainable technologies for a climate-neutral society, such as rare earths in permanent magnets and cobalt, nickel, and manganese in the cathode materials of lithium-ion batteries. The separation and purification of metals by conventional solvent extraction (SX) systems, which consist of an organic phase and an aqueous phase, has limitations. By replacing the aqueous phase with other polar solvents, either polar molecular organic solvents or ionic solvents, nonaqueous solvent extraction (NASX) largely expands the scope of SX, since differences in solvation of metal ions lead to different distribution behaviors.

Hard-Soft Interactions in Solvent Extraction with Basic Extractants: Comparing Zinc and Cadmium Halides.

Solvent extraction is often applied to separate and purify metals on an industrial scale. Nevertheless, solvent extraction processes are challenging to develop because of the complex chemistry involved. For basic extractants, much of the chemical behavior remains poorly understood due to the conditions far from thermodynamic ideality.

Opposite selectivities of tri--butyl phosphate and Cyanex 923 in solvent extraction of lithium and magnesium.

The synergic solvent extraction system of tri--butyl phosphate (TBP) and FeCl (or ionic liquids, ILs) has been extensively studied for selective extraction of Li from Mg-containing brines. However, Cyanex 923 (C923), which extracts many metals stronger than TBP, has not yet been examined for Li/Mg separation. Here, we report on the unexpected observation that the C923/FeCl system has opposite Li/Mg selectivity compared to the TBP/FeCl system.

Ethylammonium nitrate enhances the extraction of transition metal nitrates by tri--butyl phosphate (TBP).

Several molecular polar solvents have been used as solvents of the more polar phase in the solvent extraction (SX) of metals. However, the use of hydrophilic ionic liquids (ILs) as solvents has seldomly been explored for this application. Here, the hydrophilic IL ethylammonium nitrate (EAN), has been utilized as a polar solvent in SX of transition metal nitrates by tri--butyl phosphate (TBP).

Electrochemical behavior and electrodeposition of gallium in 1,2-dimethoxyethane-based electrolytes.

The electrochemical behavior and electrodeposition of gallium was studied in a non-aqueous electrolyte comprising of gallium(iii) chloride and 1,2-dimethoxyethane (DME). Electrochemical quartz crystal microbalance (EQCM) and rotating ring disk electrode (RRDE) measurements indicate that reduction of gallium(iii) is a two-step process: first from gallium(iii) to gallium(i), and then from gallium(i) to gallium(0). The morphology and elemental composition of the electrodeposited layer were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX).