在298.15K和离子强度为0.1～2.0moL·Kg~(-1)范围内,在较高浓度和浓酸度的萃取体系In_2(SO_4)_3—Na_2SO_4—D_2EHMTPA—n—C_8H_(18)—H_2O中,本文测定了萃取平衡。 In_(aq)~(3+)+3H_2A_(2(org))→In(HA_2)_(3(org))+3H_(aq)~+的In~(3+)的平衡浓度和水相pH值,其中Na_2SO_4为支持电解质。根据Pitzer电解质溶液理论,估算了平衡水相中的真实离子强度值,并用直线外推法和多项式拟合法确定了萃取过程的热力学平衡常数K~θ。 Under the condition of 298.15K and ionic strength of 0.1 ~ 2.0moL · Kg -1, in the high concentration and concentrated acid extraction system In_2 (SO_4) _3-Na_2SO_4-D_2EHMTPA-n-C_8H_ (18) -H_2O In this paper, the extraction equilibrium was determined. The equilibrium concentration of In 3+ in the range of In_ (aq) ~ (3 +) + 3H_2A_2 (org) → In (HA_2) _ (3 (org)) + 3H_ (aq) ~ + Value, where Na_2SO_4 is the supporting electrolyte. According to the Pitzer electrolyte solution theory, the true ionic strength in the equilibrated aqueous phase was estimated. The thermodynamic equilibrium constant K ~ θ of the extraction process was determined by linear extrapolation and polynomial fitting.