In hydrometallurgical recovery of LIB metals, ion exchange (IX) has hitherto played only a minor role. Separation experiments were conducted in single laboratory-scale IX columns with the aim of laying the foundation for a continuously operated multicolumn IX process similar to a simulated moving bed (SMB) configuration. In this study, the initial process developed earlier was improved by reducing the number of process steps and external streams. The desorption step with oxalate solution was examined in single-column batch experiments to ensure complete desorption of iron in the proposed continuous multicolumn IX process. Additionally, the volume flowrates were adjusted to achieve acceptable switch times of 25 min in an SMB configuration. It was found that the bead size of the resin is a critical factor in IX recovery of battery metals. The raffinate purity for the case of processing 2.5 BV lithium-ion battery waste leachate (LIBWL) improved from 97.2 % to 99.8 % when the resin bead size was reduced from 0.55 ± 0.05 mm to 0.4 ± 0.04 mm and a narrower bead size distribution. The LIBWL feed concentration was varied to mimic the dilution of fresh feed in an SMB set-up. The percentage recovery of Co and Ni decreased from 93.7 % and 96.6 % to 80.8 % and 89.4 %, respectively, when the LIBWL was diluted. This was a result of the decrease in concentration of impurity metals in the feed. Less impurity metals were sorbed and consequently, more ion exchange sites were available for the sorption of the target metals, which enhanced the retention of Co and Ni. The results were used to develop an IX column operation strategy and to suggest an initial SMB design. The multicolumn configuration presented in this work offers great potential for continuous production of high-purity Li, Ni and Co-containing raffinate (> 99.5 %).

中文翻译：

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电池金属回收中连续离子交换工艺的设计：从单柱实验到模拟移动床配置


在锂离子电池金属的湿法冶金回收中，离子交换 (IX) 迄今为止只发挥了次要作用。分离实验在单个实验室规模的 IX 柱中进行，目的是为类似于模拟移动床 (SMB) 配置的连续运行的多柱 IX 工艺奠定基础。在这项研究中，通过减少工艺步骤和外部流的数量，改进了早期开发的初始工艺。在单柱批量实验中检查了草酸盐溶液的解吸步骤，以确保在所提出的连续多柱 IX 工艺中铁的完全解吸。此外，还调整了体积流量，以在 SMB 配置中实现可接受的 25 分钟切换时间。研究发现，树脂的珠粒尺寸是电池金属 IX 回收的关键因素。当树脂珠粒尺寸从0.55±0.05mm减小到0.4±0.04mm并且珠粒尺寸分布更窄时，处理2.5BV锂离子电池废浸出液(LIBWL)的萃余液纯度从97.2%提高到99.8%。改变 LIBWL 进料浓度以模拟 SMB 装置中新鲜进料的稀释。当 LIBWL 稀释时，Co 和 Ni 的回收率分别从 93.7 % 和 96.6 % 下降到 80.8 % 和 89.4 %。这是进料中杂质金属浓度降低的结果。吸附的杂质金属较少，因此有更多的离子交换位点可用于吸附目标金属，从而增强了 Co 和 Ni 的保留。结果用于制定 IX 塔操作策略并提出初始 SMB 设计建议。 这项工作中提出的多塔配置为连续生产高纯度含锂、镍和钴的萃余液（> 99.5%）提供了巨大的潜力。