Chemistry Department, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy.
Chemistry Department, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy.
Waste Manag. 2016 May;51:214-221. doi: 10.1016/j.wasman.2015.11.003. Epub 2015 Nov 10.
An innovative process was optimized to recover Co from portable Lithium Ion Batteries (LIB). Pilot scale physical pretreatment was performed to recover electrodic powder from LIB. Co was extracted from electrodic powder by a hydrometallurgical process including the following main stages: leaching (by acid reducing conditions), primary purification (by precipitation of metal impurities), solvent extraction with D2EPHA (for removal of metal impurities), solvent extraction with Cyanex 272 (for separation of cobalt from nickel), cobalt recovery (by precipitation of cobalt carbonate). Tests were separately performed to identify the optimal operating conditions for precipitation (pH 3.8 or 4.8), solvent extraction with D2EHPA (pH 3.8; Mn/D2EHPA=4; 10% TBP; two sequential extractive steps) and solvent extraction with Cyanex 272 (pH 3.8; Cyanex/Cobalt=4, 10% TBP, one extractive step). The sequence of optimized process stages was finally performed to obtain cobalt carbonate. Products with different degree of purity were obtained depending on the performed purification steps (precipitation with or without solvent extraction). 95% purity was achieved by implementation of the process including the solvent extraction stages with D2EHPA and Cyanex 272 and final washing for sodium removal.
开发了一种从便携式锂离子电池（LIB）中回收钴的创新工艺。采用物理预处理中试规模从 LIB 中回收电极粉末。采用湿法冶金工艺从电极粉末中提取钴，包括以下主要阶段：浸出（通过酸还原条件）、初步净化（通过沉淀金属杂质）、用 D2EPHA 进行溶剂萃取（去除金属杂质）、用 Cyanex 272 进行溶剂萃取（从镍中分离钴）、钴回收（沉淀为碳酸钴）。分别进行了测试，以确定沉淀（pH 值为 3.8 或 4.8）、用 D2EHPA 进行溶剂萃取（pH 值为 3.8；Mn/D2EHPA=4；10%TBP；两个连续萃取步骤）和用 Cyanex 272 进行溶剂萃取（pH 值为 3.8；Cyanex/Co=4、10%TBP、一个萃取步骤）的最佳操作条件。最后进行了优化工艺阶段的顺序，以获得碳酸钴。根据所进行的净化步骤（有无溶剂萃取的沉淀），获得了不同纯度的产品。通过实施包括用 D2EHPA 和 Cyanex 272 进行溶剂萃取阶段以及最终去除钠离子的洗涤在内的工艺，可获得 95%的纯度。
