4. Solvent extraction of copper

There are two main routes to solvent extraction, depending on whether you're operating in sulfuric or ammoniacal media. Inherited from the processes used in nuclear energy, solvent extraction (SX process) not only aims to increase the concentration of copper in cupric solutions, to make it compatible with electrowinning (EW process), but also to reject soluble impurities.

The extraction and re-extraction reactions of copper in a sulfated solution with chelating extractants (RH) are as follows: ${[\text{2}R\text{H}]}_{\text{org }}+{\left[{\text{CuSO}}_{\text{4}}\right]}_{\text{aq}}\underset{\text{réextraction }}{\overset{\text{extraction }}{\text{⇌}}}{\left[{\text{R}}_{\text{2}}\text{Cu}\right]}_{\text{org }}+{\left[2{\text{H}}^{+}+{\text{SO}}_4^{2-}\right]}_{\text{aq}}$