Reactive Zinc Extraction with D2EHPA in a Kühni Miniplant Column

Abstract

AbstractReactive extraction of Zn2+ with di‐(2‐ethylhexyl) phosphoric acid (D2EHPA) was examined in a multistage countercurrent extraction column of type Kühni. Hydrodynamics and mass transfer for the reactive European Federation of Chemical Engineering (EFCE) test system were comprehensively experimentally investigated in a DN32 Kühni miniplant column. The experiments demonstrate that the column hydrodynamics and mass transfer performance markedly depend on throughputs, phase ratio, energy input as well as on the component concentrations. Using a simple equilibrium stage model, it was found that two to four stages per meter can be reached in the miniplant extractor. The system physical properties (density, viscosity, interfacial tension) of the reactive test system change rapidly due to mass transfer, which is considered by appropriate correlations.