A multi-stage, counter-current liquid-liquid extractor is used to separate solute $C$ from a binary mixture $(F)$ of $A$ and $C$ using solvent $B$. Pure solvent $B$ is recovered from the raffinate $R$ by distillation, as shown in the schematic diagram below.
Locations of different mixtures for this process are indicated on the triangular diagram below. $P$ is the solvent-free raffinate, $E$ is the extract, $F$ is the feed and $ {\Delta}$ is the difference point from which the mass balance lines originate. The line $PB$ intersects the binodal curve at $U$ and $T$. The lines $P {\Delta}$ and $FB$ intersect the binodal at $V$ and $W$ respectively.
The raffinate coming out of the extractor is represented in the diagram by the point :
- $T$
- $U$
- $V$
- $W$