The Extraction Separation Of Am(Ⅲ) And Eu(Ⅲ)

The separation of trivalent actinides ((An (Ⅲ)) from lanthanides cations ((Ln(Ⅲ)) is difficult because of the similar chemical properties, such as ionic radii and oxidation states, thia caused by the lanthanide and actinide' constriction. In this pape we reviewed the ectraction separation method of metal ions, introduced the mechanism, the characteristic and the application of solvent extraction, solid phase extraction and the ion-imprinting method. We reviewed the development of study on separation.In this paper, we have synthesized several materials as extractants and investigated their extracton ability for Am(Ⅲ) and Eu(Ⅲ), this paper include two sections1. (1) N, N'- bis(salicilidene)ethylenediamine (H2salen)- and its derivatives were investigated as extractants for the separation of Am(Ⅲ) and Eu(Ⅲ). As results, H2salen is effective extractant for the mutual separation of Am(Ⅲ) and Eu(Ⅲ) under the experiment conditions. The maximum SFAm/Eu of 96 was obtained in the extraction system using nitrobenzene as diluent. Eu(Ⅲ) can be extracted from hydrochloric acid solution in the different form M (H3salen)·Cl4, M (H2salen)Cl3 and M (salen)Cl at different pH by H2salen/nitrobenzene. And yet Am (Ⅲ) can be extracted from hydrochloric acid solution in M(H2salen)Cl3 only. The effect of molecular structure of four ligan on the extraction for Am (Ⅲ) and Eu(Ⅲ)were studed. The extacion of Am (Ⅲ) and Eu (Ⅲ)from 0. 1 mol/L LiCl medium with these schiff base ligands in chloroform, as the results showed that the order of extraction ability for Am(Ⅲ) and Eu(Ⅲ) is sci4>sci2>sic3>schiff baseⅠ> schiff baseⅡ, and the extraction selectivity for Am(Ⅲ) is sci4> schiff baseⅠ> sic3> sci2. The obtained maximum separation factors (SFAm/Eu) are 9.4,2.8,2.5,2.1. Sci4 was thus chosen as an extractant to detected the effect of concentration on Am(Ⅲ) and Eu(Ⅲ)extraction from acid solution and the content of the coordination complex were deduced, sci4 conplexed with Eu(Ⅲ) in form 1:1, with Am(Ⅲ) in form 2:1 or 3:1.(2) A tripodle ligand was synthesised and crystal structure of tripod liand and a intermediate product were obtained. The reaction mechanism of the tripod was proposed. As extractant for Am(Ⅲ) and Eu(Ⅲ) the tripod ligand was studied, as the result showed that the ligand could extract Am(Ⅲ) and Eu(Ⅲ) only at high pH.2. (1) he Fe3O4 magnetic nanoparticles were synthesized by chemical coprecipitation of FeSO4·7H2O and FeCl3·6H2O in ammonia solution at a certain temperature. Then, silica was coated on the surface of Fe3O4 nanoparticles using a chemical precipitation method of sodium silicate. The X-ray diffraction(XRD) of Fe3O4 demonstrated that the magnetic nanoparticle was Fe3O4 and the structure of the magnetite nanopartides is spinel, According to the image of Fe3O4/SiO2 by TEM, the morphology is obviously core-shell structure, and the vibrating sample magnetometer(VSM) showed that magnetic materials was superparamagnetic as their magnetization and coercive force are almost zero. Schiff base ((1E,N1E)-N1-benzylidene-N2-((E)-2-((E)-benzylideneamino)vinyl) ethene-1,2-diamine) modified SiO2 were prepared with 3-chloropropyl trimethoxysilane (CPTMS) as coupling agents with ulrasonic technique under mild conditions. The samples were characterized by IR spectroscopy, XRD, TGA and Magnetic hysteresis loop(2)Three molecularly imprinted polymeric microspheres (MIPMs) were prepared by suspension polymerization method in aqueous system using Eu (Ⅲ) as ion-printing template, N-Phenylanthranilicacid,1-(2-pyridiny lazo)-2-Naohthalenol and-((allyl(benzyl)amino)methyl)phenol as coordination ligand, respectively,4-vinylpyridine as functional monomers and Divinylbenzne as cross-linker, The morphology including the size, size dist ribution, pore and pore dist ribution of the polymer beads was analyzed by BET analysis. The molecule selecting property of the Eu (Ⅲ) ions was detected through statics liquid method. The results showed that uniform-sized spherical IIPMs had been prepared in aqueous system by suspension polymerization method, the printing molecules selectively.(3) combining the high selectivity and good mass transport of surface molecular imprinting technique, high surface-to-volume ratio of nanoparticles and speediness of magnetic separation, two kinds of novel core—shell surface molecularly imprinted nano-composite system were synthesized for separation and recognition of Am(Ⅲ) and Eu(Ⅲ) using surface imprinting technique. .N-Phenylanthranilic acid and 4-vinylpyridine, which are the coordination ligand and functional monomer respectively and divinylbenzne (DVB) as cross-linking monomer, EuCl3·6H2O as template and then ion-imprinted thin films were coated onto the nano-silica or silica-modified Fe3O4 nanoparticle's surface through oxidation with AIBN in organic solution. The morphology and recognition properties of the surface ion-imprinted nanomaterial were investigated by transmission electron microscopy(TEM), X-ray diffraction(XRD), thermogravimetric analysis(TGA), vibrating sample magnetometer(VSM) and the recognition mechanism of template ion identification Was discussed. The Eu(Ⅲ) ion adsorption results showed that Eu(Ⅲ) ion-IP-coated silica or magnetic nanoparticles have high adsorption capacity for template ion due to specific recognition sites for template metal ions on the imprinted shell make this nanoparticles with specific selectivity and high stability,the imprinted magnetic nanoparticles could easily reach the adsorption equilibrium and magnetic separation under an external magnetic field(4) To obtained a clean and safe materials for separation of Am (Ⅲ) and Eu (Ⅲ). We get three kinds gel beads, containing sodium alginate (SA)/Ca2+/multil-wall carbon nanotubes(MWNTs), (SA)/Ca2+/Fe3O4-SiO2and (SA)/Ca2+/MWNTs/Fe304-SiO2.In this study, MWNTs are individually dispersed in aqueous solution using SA with ultrasonic wave method. Their adsorption capacity for Eu3+was investigated The result showed that it has better adsorption for Eu(Ⅲ)at pH 6.