ABSTRACT
Solvent extraction has a variety of meanings in different chemical disciplines, but in inorganic chemistry and hydrometallurgy it means the phase-transfer of metal ions or ion pairs from an aqueous solution (the aqueous phase) to an immiscible-organic-extractant phase. The solvent extraction of metals developed to its present sophisticated state largely because of, and certainly parallel with, the Manhattan Project. More recently-developed solvent-extraction systems generally consist of an extractant (the organic-phase-complex-forming compound) dissolved in a diluent (relatively inert organic liquid) in contact with the aqueous phase. Neither the diluent nor the extractant should distribute to the aqueous phase and the compound formed between the extractant and the metal must also be highly organophilic. For successful use of a solvent extraction system in analytical separations or in an extractive scintillator, it is necessary to pay attention to the conditions under which an extractant is effective in general, and for a given substance in particular.
