The thermodynamics of extracting In（ Ⅲ） with diethylhexylmonothiophosphoric acid as an extractant in a H2SO4 system is reported. The equilibrium molalities of In^3＋ ions were measured at a high acidity and ionic strengths varying from 0. 1 to 2.0 mol/kg in an aqueous phase containing Na2SO4 as the supporting electrolyte. The values of the standard extraction constant K^0 at various temperatures were obtained by the methods of extrapolation and polynomial approximation. The equation lgK^0 = - 51.95 - 5.93 × 10^3/T ＋ 6. 15 × 10^-2 T was also obtained and the thermodynamic quantities for the extraction process were calculated.
LIU Xing-zhi ZANG Shu-liang FANG Da-wei LI Jun WANG Lu-ning
