摘要
本文探讨了石油亚砜在盐酸介质中萃取分离锆铪时各种因素对萃取率和分离系数的影响,确定了萃合物的组成,求出了萃取反应的表观热焓,并根据光谱分析结果,提出了石油亚砜对锆铪的萃取机理。
In this work, the distribution coefficients of Zr and Hf in extraction by petroleum sulfoxide were examined experimentally under variety of Conditions. Zr was more easily extracted than Hf in hydrochloric acid solution. When the concentration of HCl was between 5.0 and 6.0M, the separation factor can be greater than 9. It was concluded that the chemical formula of the extractive complex was MCl_4·2HCl·2PSO. The extraction reaction goes as follows: (a) MCl_n^(4-n)+(4-n)Cl^-+2H_2O+2PSO_((0))≒(MCl_4·2PSO·2H_2O)_((0)) (b) MCl_n^(4-n)+(4-n)Cl^-+2PSO_((0))+2HCl+6H_2O≒(H^+·3H_2O·PSO)_2·(MCl_6^(2-))_((0)) Where M representing the metal ion of interest. The equilibrium constant of the reaction for Zr are K_(020)=3.26 and K_(022)=4.02. As for Hf, there exists the relationship of K_(020)/K_(022)=3.24. The apparent enthalpy changes for the extraction reaction are △H_(Zr) 22.4 and △H_(Hf) 22.5 kJ/mol respectively. Results of NMR spectra of extractive complex suggest that hydrogen ions form hydrogen bonds with sulfoxide groups (S=0), and FT-IR spectra hint a possibility that the oxygen atom in the sulfoxide group coordinates directly with M(Ⅳ) ions in the complexes.
出处
《化工冶金》
CAS
CSCD
北大核心
1990年第4期317-325,共9页
关键词
石油亚砜
萃取
锆
铪
分离
Petroleum sulfoxide Extraction Zirconium Hafnium Separation
