Extraction experiments
The reactive extraction of sulfuric acid and Fe(III) simultaneouslywere performed in a 250 mL beaker at desired temperatureand ambient atmosphere. The experiment was commenced bystirring the mixture of organic solution and aqueous solution for15 min unless stated otherwise. After the desired reaction time wasreached, the mixture was left for 30 min for phase separation, andsamples (2 mL) of aqueous solution were withdrawn for analytics.Following the procedure described above, the reagent concentrations,the temperature and the volume ratio of the ferric solution
and the extraction solution were adjusted to determine their effectsupon the pH and the Fe(III) concentration of the raffinate. The
counter current extraction is performed as description in the ref