Integrated Leaching and Separation of Metals Using Mixtures of Organic Acids and Ionic Liquids

Amino Acid Leaching of Critical Metals from Spent Lithium-Ion Batteries Followed by Selective Recovery of Cobalt Using Aqueous Biphasic System

To reduce the exploitation of mine resources and decrease the harm to the environment caused by urban electronic wastes, the recovery of critical metals in secondary resources is crucial. In this study, we have successfully developed an eco-friendly process to integrate the leaching and separation of cobalt (Co) from a spent lithium-ion battery (LIB) cathode using an amino acid-based aqueous biphasic system (ABS). We, for the first time, demonstrated a simple method for leaching a LIB cathode using only amino acids. In addition, we have investigated the leaching mechanism using the typical cathode active material lithium cobalt oxide (LiCoO₂). Then, the Co was selectively extracted by a biphasic system (amino acid-PPG400-H₂O). This novel process has an excellent prospect in the field of spent-battery recycling because of its eco-friendly and process-simplified advantages.

Green separation of lanthanum, cerium and nickel from waste nickel metal hydride battery

In a circular economy context, there is a growing need for more sustainable waste management options to recover elements from end-of-life materials. These "secondary ores" represent a source of critical elements that are often present in higher concentration compared to their primary ore. In this work, the recovery of lanthanum (La) from waste nickel metal hydride battery (NiMH) leachate is investigated using an aqueous biphasic system (ABS) process based on a pluronic triblock copolymer (L35). An initial screening is performed to determine the influence of the ABS phase forming salt anion and alizarin red extractant on the La extraction efficiency and selectivity. From these results, a three-step ABS process is developed, varying only the nature of the salt and requiring no additional extractant. In a first step, the ABS composed of L35 + thiocyanate ammoniun + H₂O efficiently extracts iron, manganese, and cobalt leaving La, cerium, and Ni in solution. Nickel is subsequently recovered by precipitation using dimethylglyoxime. Finally, La is separated from cerium using the L35 + ammonium nitrate + H₂O ABS, recovering 62 g of La with 94% purity per kilogram of black mass of NiMH battery. This work highlights the applicability of ABS for the treatment of raw and complex matrices, potentially allowing for a greener hydrometallurgical treatment of wastes.