Kinetics of indium extraction by HDEHP from hydrochloric acid solutions

Two most widespread methods of taking into account the rate of the reverse process in extraction systems have been analysed. It has been shown that one of them contains a principal error caused by the use of the wrong expression for the drive force of the extraction process especially important for the systems with small equilibrium distribution coefficients. Kinetics has been studied of extraction and re-extraction of indium in the system indium - solutions of HCl-D2EhHPK in heptane. The equilibrium character of this system has been shown and the first order in metal of the direct and reverse processes has been established. Heterogeneous character of the limiting stage of these processes has been observed (the surface reaction in an adsorbed layer on the interface). The concentration dependences and activation energy of this reaction have been determined. The cations In3+ and InCl2+ make the main contribution into the interaction with an extracting agent