Scandium recovery from ion-adsorption rare earth concentrate with HEHEHP as extractant  

HEHEHP从离子吸附型稀土精矿中回收钪

作　　者：ZHANG Wei ZHU Hao LIU Shu-feng NING Shun-yan WEI Yue-zhou 张伟;朱浩;刘书峰;宁顺艳;韦悦周(Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials,School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China;School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials,School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China [2]School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Journal of Central South University》2021年第3期679-689,共11页中南大学学报（英文版）

基　　金：Projects(11705032,11975082,U1967218)supported by the National Natural Science Foundation of China;Project(2017GXNSFBA198175)supported by the Natural Science Foundation of Guangxi Province,China;Project(AA17204100)supported by the Science and Technology Major Project of Guangxi Province,China。

摘　　要：An excellent extraction selectivity towards Sc over other REEs in 4 mol/L HCl solution was achieved with the separation factor βSc/REEs over 8000 by 2-ethylhexyl phosphoric acid mono 2-ethylhexyl ester(HEHEHP)and the extraction equilibrium can be obtained within 20 min.The extracted Sc can be stripped using 5 mol/L NaOH solution as eluent at 363 K with the stripping rate of 92.1%obtained.The extraction mechanism was clearly elucidated by slope analysis,saturation extraction,IR,and NMR analysis.It was revealed that the extraction of Sc in 4 mol/L HCl solution is still dominated by cation exchange process between P-O-H and Sc,and coordination process between P=O and Sc,with 6 molecules of extractant as dimer participating in the process.Finally,a flowsheet for the recovery of Sc from ion-adsorption rare earth elements(REEs)concentrate was proposed and proved in lab-scale experiment.2-乙基己基磷酸单(2-乙基己基)酯(HEHEHP)对4 mol/L HCl稀土溶液中的钪具有极高的选择性,其分离系数βSc/REEs超过了8000,且在20 min内达到萃取平衡。萃取后的钪在363 K下,利用5 mol/L NaOH作为洗脱剂,洗脱率达到92.1%。利用斜率法、饱和萃取法、红外光谱分析和核磁共振分析阐明了萃取机理。结果表明,HEHEHP在4 mol/L HCl溶液中萃取Sc主要是以P—O—H中的H与Sc的离子交换过程,以及P=O与Sc的配位过程为主导,且6个萃取剂分子作为二聚体参与萃取。最后,提出了从离子吸附型稀土精矿中回收钪的工艺流程,并在实验室进行了验证。

关 键 词：SCANDIUM HEHEHP solvent extraction ion-adsorption rare earth 

分 类 号：TF845.1[冶金工程—有色金属冶金] O658.2[理学—分析化学]