In situ anodic leaching of Nd-Fe-B sludge with fast leaching kinetics for selective recovery of rare-earth elements  

作　　者：Xuan Xu Xiaozheng Jia Peng Jing Yuanyuan Zhang Jianguo Cui Kristina Zuzek Sturm Saso Baocang Liu Jun Zhang 

机构地区：[1]School of Chemistry and Chemical Engineering,Inner Mongolia University,Hohhot,010021,China [2]Inner Mongolia Keruixingyun Science&Technology Incubation Base Co,Ltd.,Ordos,O17010,China [3]The Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou Research Institute of Rare Earths,Baotou 014020,China [4]Department for Nanostructured Materials,Jozef Stefan Institute,Ljubjana,SI-1000,Slovenia [5]School of Chemistry and Environmental Science,Inner Mongolia Normal University,Hohhot,010022,China

出　　处：《Journal of Rare Earths》2025年第3期603-611,I0007,共10页稀土学报(英文版)

基　　金：Project supported by the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2021BS02007,2022MS02014);the"Science and Technology Project of Ordos"Program(2021 CGI 17-9,2021 ZDI11-14);the National Natural Science Foundation of China(21971129,21961022,51903125,21661023);the"Inner Mongolia Autonomous Region 2022 Leading Talent Team of Science and Technology"Program(2022LJRC0008);China Postdoctoral Science Foundation(2018M640043,2019T120038)。

摘　　要：Neodymium-iron-boron(Nd-Fe-B)sludge is an important secondary resource of rare-earth elements(REEs).However,the state-of-the-art recycling method,i.e.,HCl-preferential dissolution faces challenges such as slow leaching kinetics,excessive chemical consumption and wastewater generation.In this work,the in situ anodic leaching of Nd-Fe-B sludge was developed to selectively recover REEs with high efficiency.The leaching rates of the REEs are 2.4-9.0 times higher using the in situ anodic leaching at the current density from 10 to 40 mA/cm^(2)than using conventional chemical leaching under the maintained pH of 3.7.Mechanism studies reveal that the anode-generated H~+plays the key role during the in situ anodic leaching process that locally increases the H^(+)concentration at the interface of sludge particles,accele rating the leaching kinetics.By achieving a total leaching efficiency of Nd-Fe-B sludge close to 100%and the Fe deposition efficiency in the range of 70.9%-74.3%,selective leaching of REEs is successfully realized and thus largely reduces chemical consumption.Additionally,a two-step recycling route involving electrolysis-selective precipitation was proposed that enables a stable REEs recovery of 92.2%with recyclable electrolyte.This study provides a novel and environmentally-friendly strategy for the efficient recovery of REEs from secondary resources.

关 键 词：Nd-Fe-B sludge Selective leaching Anode-generated H~+ Leaching kinetics REEs recovery 

分 类 号：TF845[冶金工程—有色金属冶金]