中文摘要：

以二异丁基甲酮（DIBK）为萃取剂，二（2-乙基己基）磷酸酯（P204）为改质剂，利用对数函数外推法对DIBK—P204体系从HSCN介质中萃取锆和铪的热力学进行研究，结果表明：锆铪与SCN-所形成配合物的一级稳定性常数分别为1×10^10.07和1×10^-0.12，DIBK-P204体系萃取锆和铪的热力学平衡常数分别为lg（K12,Zr）=5．00和lg（K12．Hf）=-4．69，焓变分别为△HZr=-13．76kJ·mol^-1和△日Hf=-13．05kJ·mol^-1，说明对锆铪的萃取反应为放热反应，升高温度不利于萃取反应的进行，并计算出常温下萃取反应的自由能变分别为△GZr=-28．06kJ·mol^-1和△GHf=26．32kJ·mol^-1，熵变分别为△Sz，=48．78J·（K·mol）^-1。和△SHf=-134．30J·（K·mol）^-1。

英文摘要：

With the diisobutyl ketone （DIBK） as extraction agent and the di（2-ethylhexyl） phosphoric acid （P204） as modifying a- gent, the thermodynamics of the solvent extraction of zirconium and hafnium from thiocyanic acid medium were studied by the logarith- mic extrapolation. The results showed that the thermodynamic equilibrium constants （lg（K12,zr） and lg（K12,Hf） ） of the extraction of zirconium and hafnium were imputed as 5.00 and - 4.69 individually, and the stability constants of complexes formed by zirconium and hafnium with SCN- were 1 × 10^10.07 and 1 × 10^-0.12 , respectively. The enthalpy, changes of exlxaction of zirconium and hafnium were calculated as - 13.76 and - 13.05 kJ·mol^-1, respectively. The results clearly showed that the extraction process of both zirconi- um and hafnium by the DIBK-P204 system was exothermic and imposed a negative influence with temperature. At room temperature, the values of AG of zirconium and hafnium （△Gzr and △GHf） were -28.06 and 26.32 kJ·mol^-1 , and the values of AS of zirconium and hafnium （ ASzr and ASm） were 48.78 and - 134.30 J.（K·mol） ^-1, respectively.