Lithium Ion Wet Recovery and Extraction Solution for TOC Removal

Ternary lithium-ion batteries are generally composed of a positive electrode, a negative electrode, an electrolyte, a current collector, a separator, and a casing. After multiple charge and discharge cycles, the electrode material structure is damaged, resulting in severe capacity decay. When the battery capacity decays to 70% to 80% of its initial capacity, it needs to be replaced.

The composition of waste ternary lithium-ion batteries is complex. In order to improve the effective recovery rate of materials, pretreatment processes are used to obtain different material streams to ensure the effective separation of positive electrode active materials for further processing. The pretreatment process usually includes the following steps: discharge, dismantling, separation, and separation of positive electrode active materials.

The wet metallurgical method is the most important method for recovering ternary lithium-ion batteries, which includes leaching and purification processes (such as solvent extraction, chemical precipitation, electrochemical deposition, etc.). Due to its high recovery rate of valuable metals, low pollution, and easy control, it is widely used.

After the positive electrode material is leached by organic leaching agents (citric acid, oxalic acid, formic acid, etc.) or inorganic acids (sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, etc.), valuable metals such as Li, Ni, Co, Mn, Cu, Al, and Fe enter the leaching solution. In order to separate valuable metals from complex solutions, solvent extraction method has been widely used for the recovery and separation of metals in the leaching solution due to the high selectivity of extractants for different metal ions. It can quickly and efficiently separate valuable metals in the leaching solution.

After filtration, adjust the pH value of the leaching solution, use P204 to extract and remove impurities. For cobalt, use P507 to extract and separate Co and Li. After using sulfuric acid for stripping, high-purity cobalt sulfate solution is obtained. After solvent extraction and recovery of cobalt, the raffinate is concentrated and added with saturated sodium carbonate to precipitate lithium in the form of lithium carbonate.

It is worth noting that due to the presence of hydrophilic groups in the organic phase, it is impossible to completely agglomerate and separate the oil particles in the subsequent process. Therefore, the oil phase components will be carried in the extracted residue and reverse extraction solution. If the carried oil phase is not removed, it will have a serious impact on the purity and performance of the subsequent nickel/cobalt products.

Haipu HP268 is a polymer based porous adsorption resin with excellent pore structure, high specific surface area, and pore volume, which can be specifically used for oil removal from water bodies. It has good mechanical and chemical stability, and the inner and outer surfaces are rich in functional groups with strong affinity for oil, making it more effective for oil adsorption in water bodies. HP268 has a large adsorption capacity for oil, fast adsorption rate, easy regeneration, simple operation, and long service life.

HP268 is suitable for: removing heterocyclic rings from leaching solution, removing TOC (residual P204P507 sulfonated kerosene, etc.) from cobalt sulfate nickel sulfate feed solution. The minimum TOC can be reduced to below 20mg/L. In addition, it can also be applied to the resource treatment of oily wastewater generated by extraction process, and various feed solutions for oil removal. The overall process is efficient and green, and no new impurities are introduced in the feed solution, with obvious economic benefits, which is conducive to promoting the recovery and development of lithium-ion batteries.