Evaluation of the separation technology in a pilot plant

El trabajo consiste en un estudio bibliográfico acerca del reciclaje de las baterías de ion litio y más concretamente del proceso de extracción líquido-líquido del cobalto que éstas contienen. Después de realizar un análisis bibliográfico, este proceso se ha estudiado mediante experimentos primero a escala laboratorio y, posteriormente, en una planta piloto consistente en un conjunto de mezcladores-sedimentadores, donde diversos parámetros influyentes en el proceso han sido estudiados. Dos distintos disolventes: Cyanex 272 y Versatic Acid 10 han sido estudiados en ambos sistemas.La importancia de este estudio se basa en el incremento constante del consumo de metales como litio, cobalto, níquel, etc. los cuales son escasos, en diferentes aplicaciones tecnológicas: baterías de automóviles, baterías de móviles, paneles solares, etc. De este modo, mediante este trabajo se intenta realizar una importante introducción a este campo, realizando un estudio útil sobre el que poder trabajar posteriormente.<br /

Review of achieved purities after li-ion batteries hydrometallurgical treatment and impurities effects on the cathode performance

This paper is a product purity study of recycled Li-ion batteries with a focus on hydromet-allurgical recycling processes. Firstly, a brief description of the current recycling status was presented based on the research data. Moreover, this work presented the influence of impurities such as Cu, Fe and Mg on recovered cathode materials performance. The impact of the impurities was described depending on their form (metallic or ionic) and concentration. This work also reviewed hydromet-allurgical recycling processes depending on the recovered material, obtained purity and recovery methods. This purity data were obtained from both research and battery industry actors. Finally, the purity study was completed by collecting data regarding commercial battery-grade chemical compounds and active lithium cathode materials, including required purity levels and allowed impurity limitations

Electrolyte recovery from spent Lithium-Ion batteries using a low temperature thermal treatment process

Electrolyte recovery is seldomly considered in state-of-art lithium-ion battery recycling methods but rather evaporates and decomposes uncontrolled during the pre-treatment steps. However, controlled and safe removal of the electrolyte is inevitable and of high importance to the recycling industry to minimize the environmental impact of the recycling processes by preventing severe threats produced by the inflammable, toxic and hazardous components of the electrolyte. This study investigated the effects of temperature and process time of a low temperature thermal treatment process on electrolyte recovery. The process exhaust gases and recovered products were analyzed by In-Situ Fourier-transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC–MS) to determine the effectiveness of the significant process parameters. The results show that the electrolyte solvents, which are dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and ethylene carbonate (EC), were successfully recovered for 80\ua0minutes of processing time at 130\ua0\ub0C. The LiPF6 decomposition products hydrogen fluoride (HF) and phosphoryl fluoride (POF3) were detected in the exhaust gas stream and recovered as acidic solutions. Thermal treatment below 150\ua0\ub0C is a promising approach for the recovery of the electrolyte solvents prior to the metal recycling stage due to its simplicity, feasibility, and environmental benefit

Complete and selective recovery of lithium from EV lithium-ion batteries: Modeling and optimization using oxalic acid as a leaching agent

The necessity of a feasible process for the recycling of lithium-ion batteries is nowadays evident due to the significant demand for raw materials for battery production, but also due to legislative requirements to achieve certain recycling efficiency with sufficient quality of the products. Special conditions to achieve high lithium recovery and its use in new batteries represent a challenge for a commercial hydrometallurgical approach. In this work, an early selective recovery of lithium using oxalic acid as a leaching agent is investigated. The different solubility of transition metals oxalates in comparison to lithium oxalate was the main driving force to achieve selective separation in the leaching step. Nickel, cobalt, and manganese oxalates are insoluble and remained in the solid residue, while lithium oxalate was dissolved in the solution. Using a design of experiments to optimize the operation, optimal parameters were identified as 60 \ub0C, 60 min, 0.6 M oxalic acid, resulting in 98.8% leaching yield for lithium, while less than 0.5 % of cobalt and nickel, and 1.5% of manganese were leached. This can significantly improve the lithium recovery in the current recycling processes. Moreover, aluminum was completely dissolved, which is a phenomenon not reported previously. It would constitute an advantage to the subsequent recycling operations

Innovative recycling of organic binders from electric vehicle lithium-ion batteries by supercritical carbon dioxide extraction

The growing demand for energy storage devices due to the skyrocketing production/consumption of portable electrical and electronic equipment as well as electric vehicles has promoted battery technologies, resulting in the piling of a large number of waste lithium-ion batteries (LIBs). Organic binders wrapped on electrode particles are usually the main reason that causes the difficulty of liberation and extraction of electrode materials. Pyrolysis or incineration is the general approach to separate the organic binder, leading to fluorinated exhaust gas emissions. In this study, the supercritical carbon dioxide (SC CO ) combined with a cosolvent dimethyl sulfoxide was innovatively adapted to enable the extraction of organic binders from spent LIBs to facilitate the liberation of the cathode material from aluminum foil. Pure polyvinylidene fluoride was preferentially used to study the SC CO dissolution mechanism. The results indicate that 98.5 wt% polyvinylidene fluoride (PVDF) dissolves in SC CO dimethyl sulfoxide system under the optimum conditions; 70\ub0C process temperature, 80 bar pressure, and 13 min duration. After removing PVDF, the recovered sample was characterized by Fourier Transform Infrared Spectrometer (FTIR) and thermogravimetric analyzer (TGA) to observe its possible re-utilization. It is clear that the surficial chemical groups and content remained the same after treatment. SC CO processing effectively liberates the active cathode material from the aluminum substrate due to removal of the binder. The suggested innovative approach is promising as an alternative pretreatment method due to its high efficiency, relatively low energy consumption, and environmentally friendly features

Novel approach to recycling of steel swarf using hydrometallurgy

Steel swarf is a hazardous waste which is challenging to recycle due to its high content of heavy metals and cutting fluids and is today commonly landfilled. The swarf can contain up to 80% iron and represents a potential secondary raw material for production of reagents like ferric chloride, which can be utilized in wastewater treatment. This work presents a novel hydrometallurgical approach for recycling steel swarf and production of ferric chloride by selective separation of iron from heavy metals. Swarf containing 69% iron was leached with hydrochloric acid. A leachate containing 24.600 mg/L Fe with 150 mg/L Mn, 12 mg/L Ni and &lt;1 mg/L Cr and Mo was obtained. The oil-based cutting fluids largely remained in the solid residue with only 1% dissolution in the aqueous phase. These findings showed that ferric chloride solutions of 99% purity can be produced from steel swarf in a single leaching step

Optimization of manganese recovery from a solution based on lithium-ion batteries by solvent extraction with d2ehpa

Manganese is a critical metal for the steelmaking industry, and it is expected that its world demand will be increasingly affected by the growing market of lithium-ion batteries. In addition to the increasing importance of manganese, its recycling is mainly determined by trends in the recycling of iron and steel. The recovery of manganese by solvent extraction has been widely investigated; however, the interaction of different variables affecting the process is generally not assessed. In this study, the solvent extraction of manganese from a solution based on lithium-ion batteries was modeled and optimized using factorial designs of experiments and the response surface methodology. Under optimized conditions (O:A of 1.25:1, pH 3.25, and 0.5 M bis(2-ethylhexyl) phosphoric acid (D2EHPA)), extractions above 70% Mn were reached in a single extraction stage with a coextraction of less than 5% Co, which was mostly removed in two scrubbing stages. A stripping product containing around 23 g/L Mn and around 0.3 g/L Co can be obtained under optimized conditions (O:A of 8:1, 1 M H2SO4 and around 13 min of contact time) in one stripping stage

Physical separation, mechanical enrichment and recycling-oriented characterization of spent NiMH batteries

Nickel–metal hydride (NiMH) batteries contain high amount of industrial metals, especially iron, nickel, cobalt and rare earth elements. Although the battery waste is a considerable secondary source for metal and chemical industries, a recycling process requires a suitable pretreatment method before proceeding with recovery step to reclaim all valuable elements. In this study, AA- and AAA-type spent NiMH batteries were ground and then sieved for size measurement and classification. Chemical composition of the ground battery black mass and sorted six different size fractions were determined by an analytical technique. Crystal structures of the samples were analyzed by X-ray diffraction. Results show that after mechanical treatment, almost 87\ua0wt% of the spent NiMH batteries are suitable for further recycling steps. Size classification by sieving enriched the iron content of the samples in the coarse fraction which is bigger than 0.25\ua0mm. On the other hand, the amounts of nickel and rare earth elements increased by decreasing sample size, and concentrated in the finer fractions. Anode and cathode active materials that are hydrogen storage alloy and nickel hydroxide were mainly collected in finer size fraction of the battery black mass

Intensification of lithium carbonation in the thermal treatment of spent EV Li-ion batteries via waste utilization and selective recovery by water leaching

The recycling of lithium-ion batteries remains an essential question, the recovery of lithium is a central matter since the European Commission identified it as a critical raw material. This article proposes a more effective technology in which lithium will be recovered as lithium carbonate earlier in the recycling process using thermal pre-treatment and water leaching. Two thermal treatments are compared: incineration and pyrolysis, the whole cell (cathode, anode, current collector foils, and separator) is thermally treated in a first route, while the separator is removed, in a second route. The separator\u27s presence showed a significant positive effect on the recovery, with an optimal recovery of 62% after pyrolysis at 700\ub0C for 1 h and water leaching at 25\ub0C with a solid-liquid ratio of 1:50 g/ml. Under these conditions, the solution purity was 92%, and aluminum was leached together with lithium. After evaporation, lithium carbonate and fluoride are found in the residue

Hydrometallurgical recycling of EV lithium-ion batteries: Effects of incineration on the leaching efficiency of metals using sulfuric acid

The growing demand for lithium-ion batteries will result in an increasing flow of spent batteries, which must be recycled to prevent environmental and health problems, while helping to mitigate the raw materials dependence and risks of shortage and promoting a circular economy. Combining pyrometallurgical and hydrometallurgical recycling approaches has been the focus of recent studies, since it can bring many advantages. In this work, the effects of incineration on the leaching efficiency of metals from EV LIBs were evaluated. The thermal process was applied as a pre-treatment for the electrode material, aiming for carbothermic reduction of the valuable metals by the graphite contained in the waste. Leaching efficiencies above 70% were obtained for Li, Mn, Ni and Co after 60 min of leaching even when using 0.5 M sulfuric acid, which can be linked to the formation of more easily leachable compounds during the incineration process. When the incineration temperature was increased (600–700 \ub0C), the intensity of graphite signals decreased and other oxides were identified, possibly due to the increase in oxidative conditions. Higher leaching efficiencies of Mn, Ni, Co, and Li were reached at lower temperatures of incineration (400–500 \ub0C) and at higher leaching times, which could be related to the partial carbothermic reduction of the metals