Liquid-liquid extraction of gallium(III) from acidic nitrate media with bis(2-ethylhexyl) phosphinic acid in toluene

The distribution equilibria of gallium(III) between bis(2-ethylhexyl) phosp hinic acid dissolved in toluene and acidic aqueous nitrate media has been i nvestigated as a function of the concentration of extractant in organic pha se and concentration of hydrogen ion and gallium(III) ion in aqueous phase. The extraction characteristics of bis(2-ethylhexyl) phosphinic acid are co mpared with that of bis(2-ethylhexyl) phosphoric acid to get further inform ation. The stoichometry of the extracted species is determined on the basis of slope analysis and IR spectra. Gallium is extracted by a cation exchang e mechanism as GaR3 by bis(2-ethylhexyl) phosphinic acid and as GaR3.HR by bis(2-ethylhexyl) phosphoric acid. Temperature dependence of the extraction equilibrium is examined by temperature variation method. Both extraction p rocesses are endothermic in nature and increase in temperature is favorable .