Extraction columns in hydrometallurgy

Extraction columns are highly efficient and can be used in hydrometallurgy with modern liquid ion exchangers exhibiting fast chemical kinetics. Zinc extraction with di(2-ethylhexyl) phosphoric acid refers as an example for a basic design involving mass transfer and reactive equilibria. In respect to column hydrodynamics the usage of physically more reliable models, like the droplet population balance model, DPBM, is recommended and case studies are given. The problems involved in deriving the necessary simulation parameters from data banks, correlations or lab-scale experiments are discussed. As could be shown, column behaviour, even from literature sources, could be well predicted without usage of any efficiency or other fit parameter. In that respect, DPBM calculations should be the future standard when simulating extraction columns performance.