Di-2-ethylhexyl phosphoric acid DEHPA

The extractant is di(2-ethylhexyl) phosphoric acid (DEHPA) in conjuction with trioctyl phosphine oxide (TOPO). Stripping is by ammonium carbonate, and uranium precipitates as ammonium uranyl tricarbonate. The mixture shows a synergistic effect. The mixture is stable, and extracts uranium in hexavalent state. 

Under appropriate experimental conditions with pH-PFCCC, major matrix elements such as Ca and Mg in enriched tap water were found to be separated from trace elements. " Trace Cd, which will appear between chromatographic bands of Mg and Ca when using di(2-ethylhexyl) phosphoric acid (DEHPA) as an extracting reagent, was well determined without interference by alkali metals. 

In early studies, di-(2-ethylhexyl) phosphoric acid (DEHPA) had been chosen as the extractant (22). DEHPA extracts americium from the solutions of low acid concentrations such as 0.1 M, while a small percentage of americium is carried with the precipitate formed by denitration of the HLW with formic acid for acidity adjustment. At the end of the denitration, the pH of solution has to be kept lower than 0.5 to avoid the loss of americium more than 0.1 % due to coprecipitation with zirconium, molybdenum and tellurium. 

A great variety of carriers are used in the LM transport (see examples in the respective chapters). They may be divided to cation-, anion-exchangers, and neutral ligands. First group is the big number of organic acids and their derivatives and related proton donors. For example, some commercially available extractants di(2-ethylhexyl)phosphoric acid (DEHPA), bis... 

Anionic Sodium bis(2-ethylhexyl sulfosuccinate) [AOT] Bicyclic sulfonates Di(2-ethylhexyl) phosphoric acid [DEHPA] Di(2-ethylhexyl) phosphorothioic acid [DEPTA] Di(oleyl) phosphoric acid [DOLPA] Di(tridecyl) phosphoric acid Sodium dodecylbenzenesulfonate [SDBS]/1-butanol [4, and references therein] [5] [6,7] [8] [9,10] [11] [12]... 

Uranium is found in phosphate ores which are mined and processed to produce a fertilizer product of high phosphate content. The first step in the recovery of phosphate from ore consists of digestion with sulfuric acid followed by uranium removal. To date, the process is economical only if uranium is recovered as a by-product. Three solvent extraction processes are in commercial operation using the following extractants a mixture of di(2-ethylhexyl)phosphoric acid (DEHPA) and trioctylphosphine oxide... 

Ternary reverse micelles composed of NaAOT, di(2-ethylhexyl) phosphoric acid (DEHPA) and di(2-ethylhexyl) phosphorothioic acid (DEPTA) in isooctane were studied by Rong et al. [129]. The results indicated that both water content and micellar size in this system were larger than in single surfactant systems with AOT and DEPTA. 

Naphthenic acids (carboxylic acids) Di-2-ethylhexyl phosphoric acid (DEHPA)... 

An example of nonideal oiganic-iihase behavior arises with di-2-ethylhexyl phosphoric acid (DEHPA) in the extraction of metal cations. E ilibrium data of Troyer for extraction of copper in die presence of nickel from sulfote solution into xylene solutions of DEHFA are shown in Fig. 8.3-10. Although the organic-phase copper concentration would be expected to rise in proportion to that in the aqueous phase. 

The rate of extraction of aluminium(iii) from aqueous mineral acid by di-(2-ethylhexyl)phosphoric acid (DEHPA) has been measured and found to follow rate law (5). 

Di(2-ethylhexyl) phosphoric acid (DEHPA) HCl, organic acid-heptane Rare earth, heavy metals... 

Organophosphorus extractants such as di(2-ethylhexyl)-phosphoric acid (DEHPA), 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPA), iV-benzoyl-A-phenyUiy-droxylamine (BPHA), and tetraoctylethylenediamine (TOEDA) are often used due to their solubility properties in the stationary organic phase. ... 

Moreno, C Valiente, M. Studies on the mechanism of transport of lanthanide ions through supported liquid membranes containing di-(2-ethylhexyl) phosphoric acid (DEHPA) as a carrier. Journal of Membrane Science, 1999, 155, 155-162. 

Danesi et al. investigated separations of actinides (22-33) with various SLM systems and carriers like die neutral bifunctional phosphorus compound CMPO (23-31,33), as well as acidic [di-(2-ethylhexyl)phosphoric acid = DEHPA, dinonylnaphthalenesulfonic acid = DNNSA] (22,26-28,32,33) and basic (Primene JM-T, a mixture of and r-C22 45NH2) carriers (27,30) and determined the... 

Though the stripping of metal ions seemed to be feasible by an acid solution, the disadvantages in this case were the low solubility of PC-88A and the metal complexes in the ILs. This is also true with another organophosphorus extractant di(2-ethylhexyl)phosphoric acid (DEHPA) [12]. To develop a more practical IL-based extraction system, a new proton dissociation-type extractant, which is soluble in ILs like neutral extractants, was desired. 

Note than an acidic extractant, such as di-2-ethylhexyl phosphoric acid (DEHPA), may have a more complex chemistry than a chelating agent, HK, due to its dimerization or self-association in the orgatuc phase (Ritcey and Ashbrook, 1984a, p. 28). We have observed such behavior earlier with carboxylic acids in nonpolar orgatuc solvents. 

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