Amines as Extractants—Studies of the Organic Phase

The Chemistry of Solvent Extraction

“…In aliphatic hydrocarbon diluents, third phase formation has been observed/ 544 ' 573) The degree of aggregation of the organic phase solutes frequently depends on the amount of nitric acid extracted/ 538,548) Halo acids. The extractive behaviour of hydrofluoric acid, however, has been found to be quite different from that of the other acids/ 511, 526, 578 -58°) For many chloride/ 522, 530, 532, 558,574a ' 576,577) and some bromide (535,558,574) and iodide (530,574) (14) have been reported. The extractive behaviour of hydrofluoric acid, however, has been found to be quite different from that of the other acids/ 511, 526, 578 -58°) For many chloride/ 522, 530, 532, 558,574a ' 576,577) and some bromide (535,558,574) and iodide (530,574) (14) have been reported.…”

“…The distribution curves of hydrobromic and hydroiodic acids(5io, 526,535,539,558, 574) are s i m jj ar to t h a t of hydrochloric acid/ 507, 510, 520, 522, 523, 526, 530, 532, 538-540, 547, 551, 558, 570, 574-578) unc J er comparable experimental conditions. While excess acid extraction is immediate with HF, there is no excess acid extracted with HI up to about 7 M in the initial aqueous solution/ 510 ) Regardless of the type of the extraction isotherms, the excess acids extracted are interpreted in terms of hydrogen bihalide formation/ 507,511,520,523,530,578) Though the transfer of hydrochloric acid is markedly affected by the presence of alkali chlorides in the aqueous solution/ 78 ) the organic acid concentration only exceptionally exceeds that corresponding to R 3 NH«HC1 2 . Extraction of excess acid varies considerably with the different halo acids.…”

The Effect of Temperature on the Extraction of Nitric Acid, Uranyl, and Plutonium Nitrates by Long Chain Tertiary Amines

“…In the extraction of a metal ion, which forms complex ions in presence of a supporting electrolyte, by means of amine salt the distribution coefficient is : (2) where the £ are the summation of all species present respectively in the organic (m q ) and in the aqueous phase (m¡). The anionic exchange reaction can be written in the general form (the charges of the ionic species will be omitted for the sake of simplicity) : …”

“…The extraction of nitric acid, uranyl nitrate and plutonium (IV) nitrate from aqueous solutions by long chain aliphatic tertiary amines in suitable diluents has been the subject of several studies [1][2][3][4][5][6][7][8]. However, insufficient data on the temperature dependence of the extraction of plutonium and uranium are available [9] to allow a calculation of the ΔΉ.…”

“…In this work the influence of the temperature on the extraction of nitric acid, uranium (VI) and Pu (IV) from nitric aqueous solutions by a tertiary amine nitrate has been studied with the aim to compute the AH for the extraction processes and to improve, if possible, the uranium-plutonium separation. References [1,2,3] list an abundant bibliography on this matter.…”