【摘要】 本文提出用焙烧强化浮选法从废旧锂离子电池中回收LiMn₂O₄和石墨，研究了焙烧温度和焙烧时间对电极颗粒表面改性的影响，并采用一系列分析技术揭示了焙烧改性的机理。结果表明，焙烧改性后，浮选可使锰酸锂和石墨高效分离。电极活性材料在550℃下焙烧2 h后，LiMn₂O₄的浮选品位从未焙烧的63.10%显著提高到焙烧后的91.36%。通过电极活性材料的表面性质进行分析可知，造成LiMn₂O₄和石墨浮选分离困难的原因是电极颗粒表面被一层有机黏结剂和电解液包裹。利用XRD、SEM、 XPS和接触角分析技术，证明氧化焙烧可以有效去除电极材料表面的有机薄膜层，恢复LiMn₂O₄原本的亲水性表面，最终显著增加锰酸锂和石墨的表面润湿性差异。闭路浮选试验结果表明，最终获得的LiMn₂O₄产品，其品位和回收率分别为99.81%和99.40%。本研究为废旧锂离子电池的资源化回收提供了一种经济环保的方法。更多还原

【Abstract】 In this study, a roasting enhanced flotation process was proposed to recover Li Mn₂O₄ and grapite from waste lithium-ion batteries（LIBs）. The effects of roasting temperature and time on the surface modification was investigated, and a series of analytical technologies were used to reveal process mechanism. The results indicate that Li Mn₂O₄ can be effectively separated from graphite via flotation after the roasting. The flotation grade of Li Mn₂O₄ was significantly increased from 63.10% to 91.36% after roasting at 550 ℃ for 2 h. The TG-DTG analysis demonstrates that the difficulty in flotation separation of Li Mn₂O₄ from graphite is caused by the organic binder and electrolytes coating on their surfaces. The XRD, SEM, XPS, and contact angle analyses confirm that the organic films on the surfaces of those materials can be effectively removed by roasting, after which the wettability of Li Mn₂O₄ is regained and thus the surface wettability difference between the cathode and anode materials is increased significantly. The closed-circuit flotation test indicates that a Li Mn₂O₄ sample with high grade of 99.81% is obtained, while the recovery of Li Mn₂O₄ is as high as 99.40%. This study provides an economical and eco-friendly way to recycling waste LIBs.更多还原