Abstract: The invention is directed to a multi-stage mixer-settler for use in the lid-liquid countercurrent extraction process with tubular stages disposed at a distance from and parallel with one another in a horizontal plane with each stage including a settling chamber. A vertically mounted rotatable agitator is provided in the mixing chamber. In order to be able to use the tubular mixer-settler also for the separation of substances of value, a housing of the tubular mixer-settler is connected to act as a cathode and anodes are disposed in the settling chamber.