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1×1010.07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ΔHZr=-13.76 kJ·mol-1和ΔHHf=-13.05 kJ·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ΔGZr=-28.06 kJ·mol-1和ΔGHf=26.32 kJ·mol-1,熵变分别为ΔSZr=48.78 J·(K.mol)-1和ΔSHf=-134.30 J·(K.mol)-1。
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.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第2期266-271,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51174146)
国家科技部"十二五"国家科技支撑计划项目(2012BAB10B10)
教育部创新团队项目(IRT0974)
教育部科学技术研究重点项目(212110)
湖北省自然科学基金一般项目(2011CDB224)资助
关键词
DIBK
锆
铪
萃取
热力学
DIBK
zirconium
hafnium
thermodynamic
