The presence of chromium in iron oxides such as hematite and magnetite, hinders their dissolution in reductive-complexing formulations. The oxidative pretreatment (op) of such oxides, which results in Cr leaching from the oxide, has improved the, dissolution when subsequently treated with a reductive-complexing formulation. In this study, various oxidative reagents such as Mn(III)-L and permanganate (acidic/alkaline) reagents Were compared for their effectiveness of Cr2O3 dissolution. Because the permanganate reagents, were effective for the op of Cr-sunstituted hematites/magnetites, the relative effectivenes of permanganate reagents can be shown as HMnO4 approximate to NP > AP The op with permanganate, reagent was found to be marginally advantageous for the reductive-complexing dissolution of Cr-substituted hematites (csh) and magentites, (csm) in V(II) formulations such as. vanadium(H) picolinate, vanadium(II) ethylene-diaminetetraacetate and vanadium(II) citrate. Nevertheless, the amount of chromium released during the op step was only a fraction of its original content in the oxide, and the use of higher concentration's (greater than or equal to stoichiometric amounts) of oxidative reagents was not found to be advantageous. However, even this, small amount of Cr removal could improve the dissolution of these oxides. The nature of the dissolution profiles of csh/csm has not varied because, of the op step when compared with their dissolution profiles without the op step. The redox cycling in a typical case of 20% csh/csm has shown that the extent of dissolution can. be further improved by adopting a multicycle dissolution process.