Ultrasound-assisted bioacid leaching was examined for the extraction of valuable metals from spent lithium ion batteries (LIBs). In this work, organic acids in lemon juice were used as the leaching agent together with H2O2. Three effective factors, namely solid/liquid (S/L) ratio, lemon juice percentage, and H2O2 volume percentage, were optimized using Response Surface Methodology (RSM). The optimal conditions were found to be 0.98% (w/v) S/L ratio, 57.8% (v/v) lemon juice and 8.07% (v/v) H2O2 in the leaching liquor, achieving recovery of 100% Li, 96% Co and 96% Ni. Furthermore, the individual effects of ultrasound, H2O2 and lemon juice on metal recovery were studied and the results showed that without H2O2 or lemon juice, the metal recovery rates decreased greatly while the absence of ultrasound reduced recovery rates to a much smaller extent, indicating that both H2O2 and lemon juice were essential in the leaching process. The effect of time on the metals recoveries was examined and results showed that Li and Co recovery reached 100% with the leaching time of 35 min. The modified shrinking core modeling results suggested that chemical reaction was the rate controlling step.

中文翻译：

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天然有机酸和H2O2的超声辅助浸出废锂离子电池。

检查了超声波辅助生物酸浸提法，以从废锂离子电池（LIB）中提取有价值的金属。在这项工作中，柠檬汁中的有机酸与过氧化氢一起用作浸出剂。使用响应表面方法（RSM）优化了三个有效因子，即固/液（S / L）比，柠檬汁百分比和H2O2体积百分比。最佳条件是浸出液中的S / L比为0.98％（w / v），柠檬汁为57.8％（v / v）和H2O2为8.07％（v / v），实现了100％Li的回收率96 ％Co和96％Ni。此外，研究了超声波，H2O2和柠檬汁对金属回收率的个别影响，结果表明，没有H2O2或柠檬汁时，金属回收率大大降低，而没有超声波的情况下回收率则小得多。表明过氧化氢和柠檬汁在浸出过程中都是必不可少的。研究了时间对金属回收率的影响，结果表明，浸出时间为35 min时，Li和Co的回收率达到100％。改进的收缩核模型结果表明，化学反应是速率控制的步骤。