Extraction of Mn(II) and Co(II) from Chloride Solutions with the Di(2-ethylhexyl)phosphoric Acid/Menthol Deep Eutectic Solvent

Extraction of Mn(II) and Co(II) from chloride solutions in the system with a hydrophobic deep eutectic solvent (HDES) based on di(2-ethylhexyl)phosphoric acid (D2EHPA) and menthol is studied depending on the aqueous phase acidity, the HDES composition, the concentration of chloride ions, and the volume ratio of the system phases. The extraction mechanism for the studied metals is established. A thermodynamic analysis of the extraction process in the proposed system is carried out. Evaluation of the possibility of reusing the HDES D2EHPA/menthol on the example of the extraction of Mn(II) ions is performed for the first time. The potential for the application of the proposed HDES for isolation of metals from aqueous solutions is demonstrated.