The nonstationary behavior of a four-stage Kuhni column operated in batch mode to the point of chemical equilibrium was investigated with the objective of determining a method of generating reliable engineering design data in an easy and cheap way. Experiments were carried out under extraction and stripping conditions with the liquid-liquid reactive system adopted by the European Federation of Chemical Engineering, ZnSO4/bis(2-ethylhexyl)phosphoric acid/n-heptane. The following variables were evaluated: rotor speed, organic-phase throughput, and extractant concentration for extraction studies and proton and extractant concentrations for stripping studies. The closed-circuit method gave estimates of heights of transfer units of adequate accuracy for design purposes. On the other hand, hydrodynamic and mass-transfer parameters estimated from concentration profiles using the backflow model were found correlated, thus indicating that information on drop size distributions is required for the evaluation of individual parameters over the whole agitation range.