Synthesis Of D2EHPA-TBP Impregnated Resins And Application In Adsorption Of Vanadium(Ⅳ)

Solvent-impregnated resin combines the advantages of both solvent extraction and ion exchange technology.It has the advantages of simple operation,less reagent consumption,low environmental pollution,and simple adsorption operation,and is increasingly applied to the separation and concentration of metal ions.However,the single extractant impregnated resin has the problems of small adsorption capacity,long equilibration time,and unsatisfactory separation effect between target components and impurity ions,which limits its application in actual production.According to previous studies,the dual extractant synergistic extraction system has the advantages of high extraction rate,excellent separating effect for vanadium with impurity ions,and high phase separation speed.In this study,different extractants were combined to prepare double extractant impregnated resins,to explore whether there are synergistic effects in the resin,and select the P204-TBP double extractant impregnated resins for subsequent study.The main findings are as follows:（1）In the dual extractant impregnated resins prepared by different extractants（P204-TBP、P507-TBP、P204-N235、P204-P507、P507-N235）,three extractant combinations P204-TBP,P507-TBP,and P507-N235 have positive synergy in the resins.After comprehensive consideration,the P204-TBP double extractant impregnating resin was chosen as the best resin for the following impregnation conditions.Through the optimization of impregnation conditions,the adsorption capacity of P204-TBP double extractant resin for Ⅴ（Ⅳ）can reach 28 mg/g.（2）The prepared P204-TBP impregnated resins（D-TIRs）were used for the adsorption of vanadium solution and compared with P204 impregnated resin（DIRs）.The results show that:D-TIRs have a faster impregnation equilibration time,wider pH adaptation range,faster adsorption rates and larger adsorption capacity for vanadium adsorption,as well as better separation effect for vanadium with impurity ions.（3）Through the adsorption kinetics analysis,the determination of the diffusion control model,and ESI-mass spectrometry and infrared spectroscopy analysis of the two resin in vanadium adsorption processes,we found that the addition of TBP in the resins not only accelerates the effective diffusion coefficient of the solution in the resin particles,but also destroys the hydrogen bonds between some P204 dimers and make some P204 dimers change into single molecules,which accelerates the reaction efficiency between P204 and VO²⁺,shortens the equilibration time.In addition,the adsorption process of vanadium onto the resins changes from pseudo-second-order kinetics model to pseudo-first-order kinetics adsorption model.