EFFECTS OF STRUCTURE OF N,N-DISUBSTITUTED AMIDES ON THEIR EXTRACTION OF ACTINIDE AND ZIRCONIUM NITRATES AND OF NITRIC ACID¹

Abstract

The effects of changes in the structure of 21 N,Y-disubstituted amides on the extraction of actinide and zirconium nitrates and of nitric acid are given. Successive alkyl substitution on the cu-carbon atom greatly decreases the extraction of quadrivalent actinides and of zirconium, but only moderately decreases the extraction of hexavalent actinides and nitric acid. The extraction mechanisms for the extraction of uranyl nitrate and nitric acid are very similar to the mechanisms of extraction by trialkyl phosphates and dialkyl alkylphosphonates. However, the extraction mechanisms for the quadrivalent species by amides appear to be quite different from the mechanisms with the phosphorus compounds. A connection between the stretching frequency of the carbonyl bond in the amides and their power as extractants is substantiated in a general and qualitative way, but an exception is noted.

Advanced Hydrometallurgical Separation of Actinides and Rare Metals in Nuclear Fuel Cycle

“…The development of an N,N-dialkylamide as a new, more highly efficient extractant than TBP began in the 1960's in the USA [3,4] and, up to the present, work is also reported from Italy [5,6], France [7][8][9] , Russia [10,11], and India [12,13]. Also in the Japan Atomic Energy Agency (JAEA), development of new N,N-dialkyamides as alternative extractants to TBP began in 1992 [14,15].…”

Extraction of Uranium(VI) from Nitric Acid Solution Using Pyrrolidone Derivatives

“…It has been reported that N,N-disubstituted amides [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and N-substituted cyclic amides [20][21][22] extract U(VI) effectively. The physicochemical properties of these compounds as the extractants can be tuned by the judicious choice of alkyl groups.…”

“…Molecular modeling methods have also been used to understand the influence of amide structures on the extraction behavior of metal ions. 1,2) Amide compounds for U and Pu cycles are classified into three types based on the extraction properties, i.e., the first one is compounds such as N,N-dihexyl octanamide, which can extract U(VI) and Pu(IV) simultaneously, [1][2][3][4][5][6][7][8]21,22) the second is compounds such as N,N-di-2-ethylhexylbutanamide, which can extract U(VI) and Pu(IV) species in the high-concentration region of HNO 3 and strip only Pu(IV) species in the low-concentration region of HNO 3 , 4,9) and the third one is compounds that can extract only U(VI) [9][10][11] such as N,N-di-2-ethylhexyl-iso-butanamide (D2EHIBA). D2EHIBA has also been studied as the extractant for recovering 233 U from irradiated Th.…”

Extraction of UO 2 2 + with N , N -di(2-ethylhexyl)-2,2,3,3,4,4,4-heptafluorobutanamide from Nitric Acid Media

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ABSTRACT: In this work, N, 2,3,3,4,4, was synthesized for the extraction of UO 2 2+ from nitric acid media. IR spectroscopy, 1 H-NMR and 19 F-NMR were applied to characterize the synthesized DEHFBA.

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“…Some progresses have been made on amides extractants [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. For example, Siddall carried out investigations on N,N-dialkyl aliphatic amides as an alternative of TBP in the reprocessing of spent nuclear fuel in the early 1960's [3,4]. Manchanda Manchanda et al have completed a series of studies on the extracting U and Th distribution behavior of N,N-dialkyl amide [18,19].…”