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研究P507-Cyanex272钠皂协同萃取剂在同一水相中同时萃取Co2+,Ni2+的动力学机制,用以研究动力学层面上Co2+,Ni2+分离的可能和效果。文中测得P507-Cyanex272钠皂协同萃取Co2+,Ni2+的表观活化能分别为23.76和16.63 kJ·mol-1。综合搅拌速度和温度对萃取速率的影响,判定该协萃体系下Co2+的控制机制为扩散-化学反应混合控制,Ni2+的控制机制为扩散控制。Co2+和Ni2+的萃取速率都与层流恒界面池的恒界面积大小成正比,结合有机磷酸钠皂萃取金属离子的反应机制,认为该萃取反应区是两相界面层,或是靠近有机相一侧的双电子层区。用起始速率法测定了水相金属离子浓度和有机相萃取剂浓度分别对Co2+,Ni2+萃取速率的影响。测出Co2+浓度、Ni2+浓度、P507钠皂浓度、Cyanex272钠皂浓度4个影响因素对应Co2+,Ni2+的反应级数分别为0.98,0.48,(0.65,0.89),(0.42,0.39),确定了P507-Cyanex272钠皂协萃体系对Co2+的协萃反应速率方程式为:r=k[NaA1]0.65(o)[NaA2]0.42(o)[Co2+]0.98(i).
To study the kinetics mechanism of simultaneous extraction of Co2 + and Ni2 + from P507-Cyanex272 sodium soap synergistic extractant in the same aqueous phase to study the possibility and effect of Co2 + and Ni2 + separation on kinetic level. It was found that the apparent activation energy of P507-Cyanex272 synergistic extraction of Co2 + was 23.76 and 16.63 kJ · mol-1, respectively. Based on the influence of stirring speed and temperature on the extraction rate, the control mechanism of Co2 + in this extraction system was diffusion-chemical hybrid control, and the control mechanism of Ni2 + was diffusion control. The extraction rate of Co2 + and Ni2 + is proportional to the constant boundary area of laminar constant interface cell. Combined with the reaction mechanism of extraction of metal ions by sodium organophosphates, the extraction reaction zone is considered to be two-phase interface layer or close to the organic phase Side of the double e-layer area. The initial rate method was used to determine the effects of aqueous metal ion concentration and organic phase extractant concentration on the extraction rates of Co2 + and Ni2 + respectively. The reaction orders of Co2 + and Ni2 + were 0.98,0.48 (0.65,0.89) and (0.42,0.39), respectively, and the concentrations of P507, P507 and P507 were determined by the four influencing factors of Co2 + concentration, Ni2 + concentration, P507 sodium soap concentration and Cyanex272 sodium soap concentration. The synergistic reaction rate equation of -Cyanex272 sodium soap extraction system for Co2 + is: r = k [NaA1] 0.65 (o) [NaA2] 0.42 (o) [Co2 +] 0.98 (i).