Two stage leaching process for selective metal extraction from spent nickel metal hydride batteries
Two stage leaching process for selective metal extraction from spent nickel metal hydride batteries
复制标题
从废镍氢电池中选择性提取金属的两阶段浸出工艺
DOI：
10.1016/j.jclepro.2017.04.144
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发表时间：
2017-07-20
影响因子：
11.1
通讯作者：
Abhilash
中科院分区：
文献类型：
--
作者：
Meshram, Pratima;Somani, Hemant;Abhilash
在本研究中，通过实验和理论建立了闭环两阶段浸出工艺，用于选择性溶解废镍氢电池电极材料中的金属。第一步，将烘烤参数（例如温度、酸浓度和持续时间）优化为 300 摄氏度，2 mL H2SO4，1.5 g 正极粉末，90 分钟。该过程的热力学可行性确定了在酸烘烤过程中镍、锌和稀土元素的水溶性硫酸盐的自发形成。烘烤后，进行两阶段浸出以浸出烘烤材料中存在的不同金属。在第一阶段水浸中，75℃、1小时内提取了91.73％Ni、94％Zn、91％稀土元素，回收率较低，为36.5％Co、22.1％Fe、23.5％Mn。由于Co和Mn的回收率较低，使用NaHSO3的H2SO4溶液在95℃下进行第二阶段浸出1小时，提高了Co（55%）和Mn（74%）的提取率。发现金属的总回收率为 98.2% Ni、91.4% Co、98% Zn、97.8% Mn 和 96% 稀土元素。由于较低的酸消耗及其金属选择性，两阶段工艺（烘烤和浸出）优于阴极粉末的直接硫酸浸出。 (C) 2017 Elsevier Ltd. 保留所有权利。
In this study, a closed loop two-stage leaching process has been experimentally and theoretically established for the selective dissolution of metals from electrode material of spent Ni-MH batteries. In the first step, baking parameters, such as temperature, acid concentration, and duration were optimized as 300 degrees C, 2 mL H2SO4 for 1.5 g of cathode powder, 90 min. The thermodynamic feasibility of the process ascertained the spontaneous formation of water-soluble sulfates of nickel, zinc, and rare earth elements during the acid baking. Post-baking, a two-stage leaching was performed for leaching of different metals present in the baked material. In first stage leaching with water, 91.73% Ni, 94% Zn, 91% rare earth elements were extracted with a low recovery of 36.5% Co, 22.1% Fe, 23.5% Mn at 75 C in 1 h. Owing to the low recovery of Co and Mn, 2nd stage leaching was performed using NaHSO3 in H2SO4 at 95 degrees C for 1 h, improving extraction to Co (55%) and Mn (74%). The overall recovery of the metals was found to be 98.2% Ni, 91.4% Co, 98% Zn, 97.8% Mn and 96% rare earth elements. The two-stage process (baking and leaching) outperforms direct sulfuric acid leaching of cathode powder due to lower acid consumption and its selectivity of metals. (C) 2017 Elsevier Ltd. All rights reserved.