Recovery of Rare Earth Metals (REMs) from Nickel Metal Hydride Batteries of Electric Vehicles
Recovery of Rare Earth Metals (REMs) from Nickel Metal Hydride Batteries of Electric Vehicles
复制标题
DOI：
10.3390/min12010034
复制
发表时间：
2021-12
期刊：
影响因子：
2.5
通讯作者：
M. Jha;P. Choubey;Om Shankar Dinkar;Rekha Panda;R. Jyothi;Kyoungkeun Yoo;I. Park
中科院分区：
文献类型：
--
作者：
M. Jha;P. Choubey;Om Shankar Dinkar;Rekha Panda;R. Jyothi;Kyoungkeun Yoo;I. Park
镍氢电池（NiMH）具有高能量密度、体积精确、抗过充等特性，广泛应用于便携式电子设备和电动汽车的制造中。这些镍氢电池含有大量的稀土金属（REMs）以及Co和Ni，这些金属由于非法倾倒和不当回收而被丢弃。鉴于稀土资源的战略、经济和产业重要性，为缓解稀土资源的供需缺口和自然资源的有限性，有必要开发稀土资源的二次资源。因此，本文报道了一种可行的从废镍氢电池中回收稀土和有价金属的湿法冶金工艺流程。在H2O2浓度为10% （v/v）、温度为75°C、溶解时间为60 min的条件下，稀土元素（Nd、Ce和La）的溶解率达到90%以上。从得到的浸出液中，用10%的PC88A在pH = 1.5、O/A比为1/1的煤油中稀释，进行两段逆流萃取，回收稀土元素Nd和Ce。在pH为1.5 ~ 2.0的浸出液中选择性沉淀纯度为99%的La，滤液中留下Cu、Ni和Co。在平衡pH为2.5和5的条件下，用lix84萃取Cu和Ni，剩下Co作为余液。所开发的工艺流程是可行的，经过规模化/中试后具有工业开发的潜力。
Nickel metal hydride (NiMH) batteries are extensively used in the manufacturing of portable electronic devices as well as electric vehicles due to their specific properties including high energy density, precise volume, resistance to overcharge, etc. These NiMH batteries contain significant amounts of rare earth metals (REMs) along with Co and Ni which are discarded due to illegal dumping and improper recycling practices. In view of their strategic, economic, and industrial importance, and to mitigate the demand and supply gap of REMs and the limited availability of natural resources, it is necessary to explore secondary resources of REMs. Therefore, the present paper reports a feasible hydrometallurgical process flowsheet for the recovery of REMs and valuable metals from spent NiMH batteries. More than 90% dissolution of REMs (Nd, Ce and La) was achieved using 2 M H2SO4 at 75 °C in 60 min in the presence of 10% H2O2 (v/v). From the obtained leach liquor, the REMs, such as Nd and Ce, were recovered using 10% PC88A diluted in kerosene at eq. pH 1.5 and O/A ratio 1/1 in two stages of counter current extraction. La of 99% purity was selectively precipitated from the leach liquor in the pH range of 1.5 to 2.0, leaving Cu, Ni and Co in the filtrate. Further, Cu and Ni were extracted with LIX 84 at equilibrium pH 2.5 and 5, leaving Co in the raffinate. The developed process flow sheet is feasible and has potential for industrial exploitation after scale-up/pilot trails.