摘要
298±1K下用高速搅拌池法考察了2-乙基己基膦酸单2-乙基己基酯(HEHEHP)-正辛烷溶液从0.100mol·dm^(-3)硝酸盐水相中萃取Fe(Ⅲ)的动力学.为了分析萃取动力学机理,确定速率控制步骤在萃取体系中的准确部位,测定了HEHEHP、三辛基氧化膦(TOPO)和十二烷基磷酸钠(SDS)在正辛烷-0.100mol·dm^(-3)硝酸盐体系界面上的吸附特性.结果表明,体系中TOPO的存在使HEHEHP萃取Fe(Ⅲ)的速率减慢;将TOPO改为SDS,能使HEHEHP萃取Fe(Ⅲ)的速率加快、并就TOPO和SDS对HEHEHP萃取Fe(Ⅲ)速率的影响,首次作了定量处理.证实了HEHEHP萃取Fe(Ⅲ)动力学过程的界面特征.
The kinetics and mechanism of solvent extraction of iron (Ⅲ) with a n-octane solution of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (HEHEHP, HA) has been studied at ionic strength 0.1 and 298±1K by means of the high-speed stirring method. In order to further understand the reaction mechanism of iron (Ⅲ) with HEHEHP and to explain the catalytical role of trioctyl phosphine oxide (TOPO) and sodium dodecyl sulphonate (SDS) on the kinetic processes, so as to determine the exact location of the rate controlling steps in the reaction system, the adsorption activity of HEHEHP, TOPO and SDS at n-octane/ 0.100mol·dm-3 nitrate interface was measured respectively. The results indicate that TOPO decelerates the extraction rate of iron (Ⅲ) with HEHEHP, but SDS accelerates it. The influence of TOPO and SDS on the extraction rate of iron (Ⅲ) with HEHEHP was quantitatively dealed with.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1994年第4期373-379,共7页
Acta Chimica Sinica
基金
国家自然科学基金资助课题
