Recovery of neodymium,dysprosium,and cobalt from NdFeB magnet leachate using an unsymmetrical dialkylphosphinic acid extractant,INET-3
来源期刊：JOURNAL OF RARE EARTHS2020年第10期
论文作者：Zhengyu Liu Jiaming Wu Xinyu Liu Wen Wang Ziwei Li Ruijing Xu Yue Ding Junlian Wang
文章页码：1114 - 1118
摘 要：Rare earths （REs） and Co are critical strategic resources.Their recovery is crucial for ensuring that their supplies are adequate and for reducing environmental pollution.End-of-life NdFeB magnets are important secondary RE sources.The separation of Dy,Nd,and Co from NdFeB leachate using a relatively new extractant （2,3-dimethylbutyl）（2,4,4’-trimethylpentyl）phosphinic acid （INET-3）,was investigated in this study.The separation parameters,such as equilibrium pH,phase ratio,INET-3 concentration,and number of counter-current extraction stages,were optimised.The results show that INET-3 can separate Dy,Nd,and Co efficiently.For the preferential extraction of Dy from synthetic iron-free NdFeB leachate,the optimum equilibrium pH is 2.60.Under this condition,separation of Dy from the leachate requires four counter-current extraction stages at A/O （volume ratio of aqueous to organic）=1:2.This is demonstrated by a simulated four-stage counter-current extraction process.At equilibrium pH=2.52and A/O=1:2,98%of Dy is recovered with 95%purity.As to the subsequent separation of Nd from the leachate,nearly 100%is recovered with 99%purity through a simulated three-stage counter-current extraction process at equilibrium pH=5.33 and A/O=1:1.Approximately 95%of Co remains in the raffinate with 99.98%purity.
Zhengyu Liu1，Jiaming Wu1，Xinyu Liu1，Wen Wang1，Ziwei Li1，Ruijing Xu1，Yue Ding2，Junlian Wang1
1. School of Civil and Resource Engineering,University of Science and Technology Beijing2. Shijiazhuang Vocational College of Technology & Information
摘 要：Rare earths （REs） and Co are critical strategic resources.Their recovery is crucial for ensuring that their supplies are adequate and for reducing environmental pollution.End-of-life NdFeB magnets are important secondary RE sources.The separation of Dy,Nd,and Co from NdFeB leachate using a relatively new extractant （2,3-dimethylbutyl）（2,4,4’-trimethylpentyl）phosphinic acid （INET-3）,was investigated in this study.The separation parameters,such as equilibrium pH,phase ratio,INET-3 concentration,and number of counter-current extraction stages,were optimised.The results show that INET-3 can separate Dy,Nd,and Co efficiently.For the preferential extraction of Dy from synthetic iron-free NdFeB leachate,the optimum equilibrium pH is 2.60.Under this condition,separation of Dy from the leachate requires four counter-current extraction stages at A/O （volume ratio of aqueous to organic）=1:2.This is demonstrated by a simulated four-stage counter-current extraction process.At equilibrium pH=2.52and A/O=1:2,98%of Dy is recovered with 95%purity.As to the subsequent separation of Nd from the leachate,nearly 100%is recovered with 99%purity through a simulated three-stage counter-current extraction process at equilibrium pH=5.33 and A/O=1:1.Approximately 95%of Co remains in the raffinate with 99.98%purity.
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