文獻名：A sustainable [P6, 6, 6, 14] 2 [OPBOA]-based separation process of rare earth and transition metal in waste NiMH battery

 

 

作者： Xiang Su^abc, Wenqi Xie^c, Xiaoqi Sun^acd

a Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PR China

b School of Chemistry and Environmental Engineering, Pingdingshan University, Pingdingshan, Henan 467000, PR China

c Fujian Research Center for Rare Earth Engineering Technology, Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen, Fujian 361021, PR China

d Ganzhou Rare Earth Group Co., Ltd., Ganzhou, Jiangxi 341000, PR China

 

 

 

摘要：The separation of rare earth (RE) and transition metals is a critical step in the recycling of nickel-metal hydride (NiMH) battery. From the point of environmental and practical issues, an ionic liquid (IL) [trihexyl(tetradecyl)phosphonium]₂[2,2' -(1,2-phenylenebis(oxy))dioctanoate] ([P_6,6,6,14]₂[OPBOA]) was newly synthesized for the separation of RE from transition metals in NiMH batteries leachate. The separation factors of β_Nd/Co and β_Nd/Ni could arrive at 5.2 × 10³ and 5.4 × 10³, respectively. Meanwhile, the extracted Ni(II) and Co(II) could be effectively scrubbed and stripped by 0.5 mol/L sodium chloride (NaCl) solution without loss of RE. The loaded Nd(III) in [P_6,6,6,14]₂[OPBOA] could be quantitatively stripped by 0.014 mol/L hydrochloric acid (HCl), 0.016 mol/L sodium oxalate (Na₂C₂O₄) or 0.022 mol/L sodium carbonate (Na₂CO₃). [P_6,6,6,14]₂[OPBOA] could be recycled without regeneration when Na₂C₂O₄ and Na₂CO₃ were used as stripping agents and larger precipitated particle size could be obtained by low-concentration Na₂CO₃ solution. In the process of separating rare earth and transition metal from NiMH battery, even to handle 500 mL feed solution, the recovery efficiency and purity of RE in NiMH batteries could still reach more than 96.4% and 99.8 wt% by using NaCl and Na₂CO₃ for stripping, respectively. As characterized by XRD, the recovered RE oxides could be easily obtained by calcinations.

 

關鍵詞：Phenoxy dicarboxylic acid;Ionic liquid;Separation;Rare earth;Transition metal