Abstract

In this study, the separation of Mn from a solution containing Co and Ni using solvent extraction method was explored. Bis-2-ethylhexyl phosphoric acid (D2EHPA) as extractant was diluted in the kerosene (20 vol%), and the effect of temperature was examined at 25, 40, and 55 °C. With increasing the temperature, the value of ΔpH increased, which means that the separation has been improved. The average value of the extraction reaction enthalpy of Mn was calculated as 41.8 kJ. As the temperature rose from 25 to 55 °C, Mn extraction percent increased from 93.4 to 98.3 in pH 3, and from 82.5 to 91.7 in pH 2.6. The average value of the extraction reaction enthalpy of Co was calculated as − 16.15 kJ. With increasing the temperature, Co extraction percent decreased from 39.6 to 27.5 and from 18.8 to 11 in pH 3 and 2.6, respectively. Applying the slope analysis method, the stoichiometry of extraction reaction for three metallic ions was calculated as 4. To obtain more selectivity and purity, the separation of Mn from Co and Ni was conducted via a simple extraction-extraction-scrubbing process. For this purpose, the extraction stage pH was adjusted to 2.5 at first, which led to 84%, 8.6%, and 6.2% extraction of Mn, Co, and Ni, respectively. The stripping of the organic phase was performed at pH 1.0, and with aqueous to the organic ratio equal to 1 (1:1). The second extraction stage was conducted at pH 2.5 and subsequently a scrubbing process with concentrated Mn solution cause the extraction percent of Mn, Co, and Ni to reach 69.3, < 1, and < 0.5, respectively.

Graphical Abstract

中文翻译：

---

D2EHAP溶剂萃取法选择性分离纯化废手机锂离子电池中钴和镍中的锰

摘要

在这项研究中，探索了使用溶剂萃取法从含有Co和Ni的溶液中分离Mn的方法。在煤油（20体积％）中稀释作为提取剂的双-2-乙基己基磷酸（D2EHPA），并在25、40和55℃下检查温度的影响。随着温度升高，ΔpH值增加，这意味着分离度得到了改善。Mn的提取反应焓的平均值被计算为41.8kJ。随着温度从25升至55°C，在pH 3中，Mn的提取百分比从93.4增加到98.3，在pH 2.6中从82.5增加到91.7。Co的提取反应焓的平均值被计算为-16.15kJ。随着温度的升高，在pH 3和2.6下，Co的萃取率分别从39.6降低至27.5和从18.8降低至11。应用斜率分析法，计算出三种金属离子的萃取反应的化学计量比为4。为了获得更高的选择性和纯度，通过简单的萃取-萃取-洗涤工艺将Mn从Co和Ni中分离出来。为此，首先将萃取阶段的pH值调节至2.5，分别导致Mn，Co和Ni的萃取率分别为84％，8.6％和6.2％。有机相的汽提在pH 1.0下进行，水与有机物的比例等于1（1：1）。第二萃取步骤在pH 2.5下进行，随后用浓Mn溶液进行洗涤过程，导致Mn，Co和Ni的萃取百分比分别达到69.3，<1和<0.5。为了获得更高的选择性和纯度，可通过简单的萃取-萃取-洗涤工艺从Co和Ni中分离出Mn。为此，首先将萃取阶段的pH值调节至2.5，分别导致Mn，Co和Ni的萃取率分别为84％，8.6％和6.2％。有机相的汽提在pH 1.0下进行，水与有机物的比例等于1（1：1）。第二萃取步骤在pH 2.5下进行，随后用浓Mn溶液进行洗涤过程，导致Mn，Co和Ni的萃取百分比分别达到69.3，<1和<0.5。为了获得更高的选择性和纯度，可通过简单的萃取-萃取-洗涤工艺从Co和Ni中分离出Mn。为此，首先将萃取阶段的pH值调节至2.5，分别导致Mn，Co和Ni的萃取率分别为84％，8.6％和6.2％。有机相的汽提在pH 1.0下进行，水与有机物的比例等于1（1：1）。第二萃取步骤在pH 2.5下进行，随后用浓Mn溶液进行洗涤过程，导致Mn，Co和Ni的萃取百分比分别达到69.3，<1和<0.5。分别提取2％的Mn，Co和Ni。有机相的汽提在pH 1.0下进行，并且水与有机物的比率等于1（1：1）。第二萃取步骤在pH 2.5下进行，随后用浓Mn溶液进行洗涤过程，导致Mn，Co和Ni的萃取百分比分别达到69.3，<1和<0.5。分别提取2％的Mn，Co和Ni。有机相的汽提在pH 1.0下进行，水与有机物的比例等于1（1：1）。第二萃取步骤在pH 2.5下进行，随后用浓Mn溶液进行洗涤过程，导致Mn，Co和Ni的萃取百分比分别达到69.3，<1和<0.5。

图形概要