Parameters such as the concentrations of TOA and Fe(II), the
phase ratio and the reaction time were kept the same as mentioned
in Section 3.1.6. Temperature ranging from 25 to 45 ◦C were preformed
to test the effects on the extraction yields of Fe(III) and
sulfuric acid. The experimental results are plotted in Fig. 8. It indicates
that the increase of temperature leads to the increases of
extraction yields of Fe(III) and sulfuric acid due to the improvements
of the hydrolysis of Fe(III) and the solubility of the complex
in the organic phase.