Di-2-ethylhexyl phosphoric acid D2EHPA

Solvent Extraction. Liquid—hquid extractioa, well known ia the chemical iadustry, was first used ia extractive metallurgy for the processiag of uranium. When a dilute solution of uranium is contacted with an extractant such as di(2-ethylhexyl) phosphoric acid (D2EHPA) or R2HPO4, dissolved ia... 

L-Phenyl- alanine Di-2-ethylhexyl phosphoric acid (D2EHPA) H2SO4 Counter-trans-port of H+ ELM Concentration as cation [47]... 

The use of organophosphorus acids, such as di(2-ethylhexyl)phosphoric acid (D2EHPA di(2-ethylhexyl) monohydrogen phosphate 2 R = C4H9CH(Et)CH2), is now well established in the recovery of base metals. This reagent has found commercial application in the separation of cobalt from nickel,67 68 the separation of zinc from impurities such as copper and cadmium,69 the recovery of uranium,68 beryllium70 and vanadium,71 and in separations involving yttrium and the rare-earth metals.72 73... 

In membrane extraction of metals, the mass transport of solute from one phase to another occurs by diffusion. It is controlled by phase equilibrium and the resistances of boundary layers in two phases and the membrane material. Both types of materials are used for membrane extraction and stripping, hydrophilic and hydrophobic, and composite hydro-philic/hydrophobic barriers are also developed to avoid the membrane solubilization [122,123]. To enhance separation, the reactive liquids that induce chemical reaction with one of the separated species can be used. In membrane SX of metals, extracting agents, such as tri- -octylphosphine oxide (TOPO), di(2-ethylhexyl)phosphoric acid (D2EHPA), and n-octyl(phenyl)-A,A-diisobutylcarbamoylmethylphosphine oxide (CMPO), and commercial reagents like CYANEX 301, CYANEX 923, LIX622, and LIX622N are applied. 

Among the acidic carriers, di-(2-ethylhexyl) phosphoric acid (D2EHPA) has been the most commonly used in PIM studies. D2EHPA is a commercially available extractant that also has the ability to act as a plasticizer [23,24]. It has been... 

Kolev, S. D., Baha, Y., Cattrall, R. W., Tasaki, T., Pereira, N., Perera, J. M., and Stevens, G. W. 2009. Sohd phase extraction of zinc(II) using a PVC-hased polymer inclusion membrane with di(2-ethylhexyl)phosphoric acid (D2EHPA) as the carrier. Talanta 78 795-799. 

Synonyms Bis (2-ethylhexyl) hydrogen phosphate Bis (2-ethylhexyl) orthophosphoric acid Bis (2-ethylhexyl) phosphate Bis (2-ethylhexyl) phosphoric acid Di-2-ethylhexyl phosphoric acid D2EHPA 2-Ethyl-1 -hexanol hydrogen phosphate Empiricai C16H35O4P... 

An especially intriraing use of liquid-membrane technology, reported for the first time recently by Fox and Hayworth et al.," is the recovery of uranium from wet process phosphoric acid (WPPA). In the manufacture of fertilizer fiom phosphate rock, the acid is solubilized by treatment with sulfuric acid. In addition to HjP04, this crude leachate can contain up to 0.18 g/L of uranium. Under oxidizing conditions this occurs as the uranate ion, UO . Solvent extraction (SX) processes have been developed to recover die uranium values. One of the most common of these uses a mixture of di-(2-ethylhexyl) phosphoric acid (D2EHPA) and trioctylpbosphine oxide (TOPO) in kerosene solution. The chemistry of solvent extraction is as follows ... 

Figure 1. Monoprotic organic acids chelating ligands (a) C(7)-substituted derivatives of 8-hydroxyquinoline, OXINE Di(2-ethylhexyl)phosphoric acid, D2EHPA Variously substituted -diketonates related to acetylacetone, ACAC Variously substituted /S-hydroxyoximes LDC 65N has Rj = phenyl, R2 = H, R, ...

Solvent extraction of metal ions plays an important role in hydrometallurgy. Further development of solvent extraction is constrained by the limited number of commercially available extractants which include di(2-ethylhexyl)phosphoric acid (D2EHPA), bis(2,2,4-trimethylpentyl)phosphinic acid (Cyanex 272 ), trioctyl-phosphine oxide (TOPO), tri- -butylphosphate (TBP), some hydroxy oximes (extractants in the LIX or Acorga series) and derivatives of 8-hydroxyquinoline (extractants in the Kelex and LIX-26 series). 

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