A microextraction approach for rapid extraction and separation of Mn(Ⅱ) and Co(Ⅱ) using saponified D2EHPA system  

作　　者：Yiwei Zhou Chen Zhuo Jinpei Huang Haipeng Liu Jianhong Xu 

机构地区：[1]The State Key Laboratory of Chemical Engineering,Department of Chemical Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of Chemical Science and Engineering》2022年第6期963-972,共10页化学科学与工程前沿（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.22025801 and 21636004)for this work.

摘　　要：In this paper,we proposed a microextraction approach for the extraction and separation of Mn(Ⅱ)and Co(Ⅱ)from sulfate solution simulating leachate of spent lithium-ion battery cathode materials using saponified di-(2-ethylhexyl)phosphoric acid system.The effects of the following operational variables were investigated:equilibrium pH,tri-«-butyl phosphate concentration,saponification rate,two-phase ratio and residence time.The results showcased that the microextractor can reach the extraction equilibrium within 20 s,thereby greatly reducing necessary extraction time comparing to that of conventional processes.The volumetric mass transfer coefficient showed 8-21 times larger than that of batch device.With the help of microextractor,95%of Mn(Ⅱ)was extracted with a single theoretical stage at a chosen two-phase ratio of 3:1,and the separation factor β_(Mn/Co) was as large as 65.5.In the subsequent stripping step,more than 99%of manganese from loaded phase was easily stripped under optimal conditions.The microextraction approach greatly enhances the mass transfer while enabling a continuous and controllable extraction process within a simple structure design.When extracting spent electrode material with microextractors,the comprehensive recovery of mangenese can reach 96%.The microextraction approach has a good applicability in the spent lithium-ion battery cathode materials recycling at both bench and industrial scales.

关 键 词：extraction equilibrium mass transfer coeffi-cient MICROEXTRACTION multicomponent extraction di-(2-ethylhexyl)phosphoric acid 

分 类 号：O6[理学—化学]