an improved liquid - liquid solvent extraction system is provided having a mixing stage which includes a mixing device for creating a dispersion of the two liquid phases followed by a residence chamber designed to enhance contacting and mass transfer between the solute and solvent phases . the separating stage includes a drop size conditioning device which establishes a drop size in the discontinuous liquid phase of the dispersion which can be separated easily from the continuous liquid phase in the succeeding settling stage of the device . the drop size conditioning device also acts to reduce entrainment of the solvent phase in the solute phase during separation of the phases . the settling device may contain a series of baffles to reduce the time required for phase separation and to reduce entrainment of the solvent phase in the solute phase . the system is used to extract metal ions such as uranium , copper , cobalt , nickel , and vanadium from aqueous process streams containing dilute concentrations of such ions . hydrocarbon solvents which are partially or totally immiscible in water are used to extract the metal ions and may contain additives such as complex - forming agents to aid in the mass transfer of metal ions to the solvent phase . after contacting and separation of the phases , the metal ions are recovered from the hydrocarbon solvent .