
Speciation of the Sulfuric AcidFerric SulfateFerrous ...
iii The importance of the cathodic ferric ion reduction reaction on the overall leaching process is progressively increased when increasing the nominal Fe3+/Fe2+ ratio and temperature. Leaching is under anodic control when the nominal Fe3+/Fe2+ ratio is around 1:1, whereas at higher nominal Fe3+/Fe2+ ratios and temperatures it is under mixed control.