The Synthesis Of Diamide Compounds And The Study Of Their Extraction Properties

The separation of iron has been the popular direction of scientific research, at the same time, in the modern industrial production there are also facing a common problem, that is how to iron removal from intergrown ore. this is also our researchers' researching hot spot in recent years. Praseodymium element, one of the rare earth elements, is widely used in the aerospace and industrial manufacturing of glaze, therefore, separation and purification of Fe(III) and Pr(III) has a very important role in the development of the national economy. For now, solvent extraction has become a mainstream method of separation and enrichment of metal elements due to its high yield and the continuous unit operation. In this work, two kinds of double amides extractant have been synthesized: malonamide and3-oxy-glutaramide. The extraction property of different kinds of double amides extractant for Fe(III) and Pr(III) were investigated. The main contents are as follows:The extraction behaviors of light rare earth elements, La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) with DODPMA, N,N' –di(6-hydroxyhexyl)-N,N'-propyl-malonamide and N,N'-di(2-hydroxypropyl)-N,N'-octyl- malonamide was studied. The results showed that the extraction ability of DODPMA for all of the investigated elements basic remain unchanged with the increase of nitric acid concentration. The distribution ratio of uranium(VI) increases sharply with the adding of LiNO3 in aqueous phase. The extractant, N,N' –di(6-hydroxyhexyl)-N,N'-propyl-malonamide and N,N'-di(2-hydroxypropyl)-N,N'-octylmalonamide, can be resolved in the aqueous solution. So, it is not suitable to investigate their extraction ability.The extraction of Pr(III) with DMDDdDGA, DEDDdDGA, DPDDdDGA and DBDDdDGA studied. The effect of hydrochloric acid concentration, extractant concentration, and temperature on the extraction distribution ratio of Pr(III) were investigated. The distribution ratio of Fe(III) increases with the acid concentration under the experimental conditions and the DMDDdDGA and DEDDdDGA can form three phase in high acid concentration. The interfacial behavior of the extractant in different diluents, in the liquid-liquid(L/L) extraction of Pr(III) from hydrochloric acid and nitric acid solution, was studied to clarify the solvent effect of the diluents.The extraction of Fe(III) with N,N,N?,N?-tetrabutylmalonamide(TBMA), N,N,N?,N?-tetrabutyl-3-oxy-glutaramide(TBDGA) and N,N,N?,N?-tetrabutylsuccinamide(TBSA) was studied in order to understand the relationship between the chemical structure of the extractants and their Fe(III) extraction behaviors. The effect of hydrochloric acid concentration, extractant concentration, and temperature on the extraction distribution ratio of Fe(III) were investigated. The extraction efficiency of the extractants toward Fe(III) in toluene increases in the order: TBMA<TBSA<TBDGA. Spectroscopic data(UV-visible, IR and 1HNMR) and density functional theory(DFT) were used to clarify the extraction mechanism. Their structure of the extracted compound are as follows: [H?(2TBMA)]+[FeCl4]-, [H?(2TBDGA)]+[FeCl4]- and [H?(TBSA)]+[FeCl4]-.The performance of extraction and stripping of Fe(III) from hydrochloric acid with N,N,N',N'-tetra-2-ethylhexyldiglycolamide(T2EHDGA) in different diluents was studied in order to understand the relationship between the nature of the diluents and their extraction of Fe(III). The affect of hydrochloric acid concentration, chloride ion concentration, extractant concentration and temperature on the extraction distribution ratio of Fe(III) were investigated. Spectroscopic data(UV-visible and IR) were used to clarify the extraction mechanism. The extraction efficiency of the extractant toward Fe(III) in different diluents increases in the order: toluene < n-hexane < n-octane < n-dodecane. The interfacial behavior of T2 EHDGA in different diluents, in the liquid-liquid(L/L) extraction of Fe(III) from hydrochloric acid solution, was studied to clarify the solvent effect of the diluents. The applicability of T2 EHDGA to separate Fe(III) from Cu(II), Ni(II) and Cd(II) solution was investigated. The striping of Fe(III) were also studied and found that distilled water can achieve satisfactory result.