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.

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.

Determination of Chlorides in Ionic Liquids by Wavelength Dispersive X-ray Fluorescence Spectrometry.

The synthesis of ionic liquids (ILs) usually involves two steps: (i) quaternization of a precursor followed by (ii) a salt metathesis reaction to introduce the desired anion. A consequence of the second step is that most ILs still contain some amount of the initial anion, often chloride. In this work, wavelength dispersive X-ray fluorescence (WDXRF) spectrometry is presented for the direct measurement of chlorides in ILs.

Separation of iron(iii), zinc(ii) and lead(ii) from a choline chloride-ethylene glycol deep eutectic solvent by solvent extraction.

Deep eutectic solvents (DESs) were used as alternatives to the aqueous phase in solvent extraction of iron(iii), zinc(ii) and lead(ii). The selective extraction of iron(iii) and zinc(ii) was studied from a feed of ethaline (1 : 2 molar ratio of choline chloride : ethylene glycol) and lactiline (1 : 2 molar ratio of choline chloride : lactic acid), with the former DES being more selective. A commercial mixture of trialkylphosphine oxides (Cyanex 923, C923) diluted in an aliphatic diluent selectively extracted iron(iii) from a feed containing also zinc(ii) and lead(ii).

Dissolution of noble metals in highly concentrated acidic salt solutions.

Highly concentrated solutions of AlCl3·6H2O and Al(NO3)3·9H2O were investigated for Au and platinum group metals dissolution. 95% Pd was leached from spent automotive catalysts in 15 min at 80 °C, while Pt required longer times; Rh dissolution was <20%. Au dissolution from wires required 24 h.

Separation of neodymium and dysprosium by solvent extraction using ionic liquids combined with neutral extractants: batch and mixer-settler experiments.

A solvent extraction method based on the combination of the ionic liquid trihexyl(tetradecyl)phosphonium thiocyanate or nitrate ([C101][SCN], [C101][NO]) and the neutral extractants Cyanex 923 or tri--butyl phosphate (TBP) has been investigated for the separation of Nd(iii) and Dy(iii) from chloride media. High distribution ratios and separation factors were obtained when using Cyanex 923 diluted in [C101][SCN] 40 : 60 (wt%) and extracting from chloride media. The addition of Cyanex 923 to the ionic liquid has four advantages: (1) increase in the distribution ratios of the rare earths, (2) decrease of the viscosity of the organic phase, hence an improved mass transfer, (3) increase in the loading capacity of the ionic liquid and (4) improvement of the coalescence and phase disengagement, which is of importance when carrying out separations in continuous mode.

Direct Analysis of Metal Ions in Solutions with High Salt Concentrations by Total Reflection X-ray Fluorescence.

Total reflection X-ray fluorescence (TXRF) is becoming more and more popular for elemental analysis in academia and industry. However, simplification of the procedures for analyzing samples with complex compositions and residual matrix effects is still needed. In this work, the effect of an inorganic (CaCl) and an organic (tetraalkylphosphonium chloride) matrix on metals quantification by TXRF was investigated for liquid samples.