1. Classification of liquid-liquid extraction equipment

The devices used in solvent extraction processes are liquid-liquid contactors in which the intimate mixing of the two phases creates an interfacial area through which the solute can transfer.

There are two main classes of device:

• individual stage contactors ;

• contactors with non-individualized stages or differential contactors.

In the first stages, one phase is dispersed in the other and brought to equilibrium in the mixer, then the phases are separated by settling and sent in countercurrent to adjacent stages.

In the second type, generally consisting of vertical columns, one phase is dispersed in the other, which circulates in countercurrent, with extraction taking place continuously in the column, where an ideal concentration...