Gao J, Peng B, Fan H, Kang J
Department of Chemistry, Northwest Normal University, Lanzhou, People's Republic of China.
Talanta. 1996 Oct;43(10):1721-5. doi: 10.1016/0039-9140(96)01954-6.
The kinetics of solid-liquid extraction of rare earth elements (RE) (La, Ce, Sm, Dy and Yb) were studied with 1-(2-pyridylazo)-2-naphthol (PAN) at 60 degrees C using paraffin wax as a diluent. The rate of extraction is first order with respect to metal ion and hydrogen ion in the aqueous phase and second order with respect to the extractant in the organic phase. The rate-determining step is the formation of an RE(PAN)(2) complex between RE(3+) and PAN in the aqueous phase. The rate constant for the extraction was found to be about 10(11) 1 mol(-1) s(-1). The temperature dependence of extraction rate was determined and the activation parameters were calculated.
在60℃下，以石蜡为稀释剂，研究了用1-（2-吡啶偶氮）-2-萘酚（PAN）对稀土元素（RE）（镧、铈、钐、镝和镱）进行固液萃取的动力学。萃取速率对水相中金属离子和氢离子为一级反应，对有机相中萃取剂为二级反应。速率决定步骤是水相中RE(3+)与PAN形成[RE(PAN)(2)] (+)络合物。发现萃取的速率常数约为10(11) 1 mol(-1) s(-1)。测定了萃取速率的温度依赖性并计算了活化参数。
