5. Characteristics and constraints of an industrial system

Liquid-liquid extraction generally performs at least one of the following three functions:

• separation of solutes initially present in a complex mixture into two groups;

• concentration of a particular solute ;

• advanced purification of a given chemical compound.

Industrially, depending on the application, one of these three functions is decisive. The most economical implementation on an industrial scale is to implement a methodical countercurrent extraction system as shown in figure 8 , with each stage comprising several theoretical stages, and each flow circulating continuously