Liquid-liquid two-phase flow in extraction columns of the rotating disc contactor type is analysed using the multi-dimensional computational fluid dynamics (CFD) technique. Euler-Euler and Euler-Lagrange models are employed to give insight into the global flow structure and to analyse the turbulence related dispersion processes. Laser-Doppler velocity measurements are used to check the Euler-Euler results while a measured residence time distribution allows the assessment of the Euler-Lagrange approach. The results give rise to the expectation that CFD will become an accepted design tool in chemical engineering.