Abstract: A mixer settler system is disclosed. The system comprises a mixer [110] configured for receiving an organic phase and an aqueous phase, the mixer [110] being further configured to maintain the organic phase and the aqueous phase in a single unstable emulsion phase, wherein mass transfer occurs between said organic phase and said aqueous phase; and, a column settler [120] which is configured to receive a single unstable emulsion phase from the mixer [110] via an emulsion inlet [125] and is also configured to separate the single unstable emulsion phase into a stable organic phase and a stable aqueous phase by virtue of coalescence; the column settler further comprising an organic outlet [121] above the emulsion inlet [125] and an aqueous outlet [123] below the emulsion inlet [125]; the column settler [120] further discouraging mass transfers within the unstable emulsion phase and further promoting coalescence of each of said stable organic phase and stable aqueous phase.