A TBP/BTBP-based GANEX Separation Process. Part 1: Feasibility

The structures of CyMe4-BTBP complexes of americium(iii) and europium(iii) in solvents used in solvent extraction, explaining their separation properties

“…Recent studies have shown that poly-aromatic nitrogen compounds, N-PAHs, acting as tetradentate chelating ligands to the metal ions in the extraction, have the ability to sufficiently separate An(III) from Ln(III). [7][8][9][10] One of these N-PAHs, 6,6'-bis (5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzol [1,2,4]triazin-3-yl) [2,2]bipyridine, CyMe4-BTBP (Figure 1), has promising process potential, [11][12][13][14][15][16] as it has proven to be resistant towards acidic environments [17][18][19] and strong radiation from radioactive decomposition 13,20 Qualitative reasoning concerning the Lewis basicity of the extractant and the somewhat softer character of the actinoid(III) ions compared to the lanthanoid(III) ones has been used to explain the An(III)/Ln(III) separation capacity of N-PAH ligands. 32,33 An(III)/Ln(III) separation by CyMe4-BTBP has also been observed to vary with the solvent used.…”

Development of Highly Selective Ligands for Separations of Actinides from Lanthanides in the Nuclear Fuel Cycle

“…Mononuclear 1:1 complexes of 107 were also obtained with tetravalent Cp* 2 U 2+ ions (Cp* = pentamethylcyclopentadienyl) and with pentavalent UO 2 + ions that were formed by the reduction of the corresponding UO 2 2+ complexes with (pentamethylcyclopentadienyl)potassium or cyclopentadienylthallium. 109 A very unusual dinuclear m-oxo mixed-valence U(IV)/U(VI) complex was isolated from a mixture of U(OTf) 4 , UO 2 (NO 3 ) 2 , and CyMe 4 -BTBP (107). 77 In this complex, two ligands of 107 coordinated to the U(IV) ion in an orthogonal arrangement, while the nitrates coordinated to the U(VI) ion.…”

“…In addition, the BTBPs also extracted several d-block metals to a significant extent, in common with the tridentate BTP and hemi-BTP ligands. 100,103 The most promising of the BTBP ligands is CyMe 4 -BTBP (107), which was designed to be more resistant to radiolysis (discussed in detail in Section 9). This ligand is the most studied of the BTBP ligands, and its solvent extraction chemistry has been looked at in detail.…”

Development of the Chalmers Grouped Actinide Extraction Process

“…In recent years, TBP became a common extractant in different GANEX solvents [7,10,18]. A negative feature with TBP is, however, that it does not follow the CHON principle [19].…”

“…The different solvent systems developed all have the common denominator that they combine two different extractants; one being from the bis-triazine bipyri-dine (BTBP) family and the other being either tributyl phosphate (TBP) or the monoamide N,N-di(2--ethylhexyl)butyramide (DEHBA). In the initial process cyclohexanone was used as diluent with good results [7,8]. However, due to instability and density issues other diluents were investigated later on.…”