HEH[EHP]从硝酸盐介质中萃取钙的动力学研究

The Extraction Kinetics of Ca(Ⅱ) from Nitrate Medium with HEH[EHP]

采用上升液滴法研完了HEH(EHP)——正辛烷溶液从硝酸盐介质中萃取Ca(Ⅱ)的正向反应速率与机理,考察了不同萃取条件对萃取速率的影响,提出了速率方程,并对萃取机理进行了讨论。

The kinetics and mechanism of extraction of Ca(Ⅱ) from nitrate medium with HEH[EHP] in octane by means of the Single Drop Method were studied at 298K. The effect of the temperature on the extraction rate was also investigated. The experimental results indicate that the extraction process may be controlled by the following inter facial reactions: Ca^(2+)HA_(i)K_1(?)K_(-1)CaA_(i)^+ +H^+ CaA_(i)^+ +2H_2A_2(o)K_2(?)K_(-2)CaA_2·2HA(o)+HA(i)+H^+ the forward linitial rate of the extraciton can be expressed as follows R_f=k′[Ca^(2+)][H_2A_2]_(o)~2/k_(-1)[H!+]+k_2[H_2A_2]_(o)~2 where k'=k_1k_2[HA](i).[]denotes the initial concentration, (o)and(i), the organic phase and interfase, respectively.the reaction rate constant(k) and activation energies(E,) were calculated.