Two-amide extractant extraction of rare earth elements

Title: Two-amide extractant extraction of rare earth elements
　　Author: Zhang Yanju
　　Degree-granting unit: Jinan University
　　Keywords: amides;; synthesis;; extraction;; lanthanides
　　Summary:
　　Rare Earth is an important non-ferrous metals, in the development of new materials, ultra-pure materials preparation and other areas has important application value. Solvent extraction with fast response, good separation characteristics, has become the primary means of separation and purification of rare earths. In addition, nuclear fuel reprocessing, a goal is to use Neodymium Magnets neutrons to a long half-life actinides into short half-life isotopes, but the lanthanides can effectively capture neutrons, it is necessary to use solvent extraction method to high-level radioactive waste in the actinide and lanthanide separation.
　　New extractant scientific research and design process has been two important aspects of solvent extraction, so explore the suitable extraction solvent and extraction conditions on extraction chemistry is of great importance. Amide extractant for actinide and lanthanide extraction have a very good performance, but its associated chemical extraction and extraction properties of the theory is not enough depth. Five amide synthesized extractant, the extraction of its performance were studied in detail, the main contents include the following:
　　(1) synthesis of N, N, N ', N'-tetrabutyl-3 - oxo glutaric amide (TBDGA), N, N, N', N'-tetraethyl -3-- glutaric amide oxygen ( TEDGA), N, N'-dimethyl-N, N'-diphenyl-3 - oxygen glutaric amide (DMDPhDGA), N, N'-dimethyl-N, N'-two Decyl 3 - O glutaric amide (DMDDDGA), N, N, N ', N'-tetrabutyl Malonamide (TBMA), respectively, by infrared spectroscopy, elemental analysis, nuclear magnetic resonance analysis of its structure was characterized.
　　(2) TBDGA nitric acid extraction results show that under the conditions of low acidity, extractant and nitric acid were formed 1:1 adduct.
　　(3) study the TBDGA, DMDPhDGA, DMDDDGA nitric acid extraction of trivalent lanthanides properties and mechanisms, detailed study of the nitric acid concentration, extractant concentration and temperature on the extraction distribution ratio. Reaction mechanism has been extracted as follows: In addition to the chloroform system Dy (III) ions and four ligand molecules DMDDDGA, the other is a lanthanide ion and the three extractant molecules coordinated. For the first time using infrared spectroscopy and conductivity studies of TBDGA lanthanide complexes with the structure, that this complex is ionic complexes.
　　(4) extractant of trivalent lanthanide ions on the extraction distribution ratio in the range of experiments with the nitric acid concentration and the extractant concentration increases; in the same experimental conditions, the distribution ratio increases http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets with increasing atomic number large. The extraction reaction is exothermic, low temperatures are conducive to extraction. Obtained by calculating the extraction equilibrium constant and thermodynamic function values. The IR spectra of extracted complex that extractant molecules with metal ions through the carbonyl ligand.
　　(5) in different diluent systems studied TBDGA and DMDDDGA from the nitric acid extraction of lanthanide ions in the performance and reaction mechanism, the diluent TBDGA of different Gd (III) ions extraction capacity: xylene> tetrachloro carbon tetrachloride> toluene> chloroform, the composition of extracted complexes Gd (NO3) 3.3 TBDGA; DMDDDGA of Gd (III), Dy (III) ions extraction capacity: carbon tetrachloride> toluene> benzene> chloroform , extraction Gd (III) ions extracted complex was composed of Gd (NO3) 3.3 DMDDDGA, extraction of Dy (III) ions extracted complex was composed of Dy (NO3) 3.4 DMDDDGA. Extractant diluent not only affect the extraction efficiency, but also affect the composition of extracted complexes.
　　(6) under different experimental conditions investigated N, N, N ', N'-tetrabutyl Malonamide (TBMA) and Chung octyl phenoxy acetic acid (CA-12), bis (2 - ethylhexyl ) phosphoric acid (P204), tri-n-octyl phosphine oxide (TOPO) of Yb (III) ions co-extracted and found in the studied experimental conditions no synergy.
　　(7) the first study of the solid complexes La2 (NO3) 6.3 TEDGA, Pr2 (NO3) 6.3 TEDGA the crystal structure, both of which are triclinic, P1 space group. Three TEDGA molecules and lanthanum, praseodymium ions are tridentate ligand forms six bidentate coordination of nitrate and other metal ions.
　　Degree Year: 2010