The rate of leaching of iron from ilmenite (FeTiO3) in hydrochloric acid (HCl) solutions is greatly enhanced by the presence of ultraviolet (UV) light. The magnitude of the air purged UV light illuminated leaching rate is approximately twofold higher than the N2 purged leaching rate under dark conditions. The enhanced rate is attributed to the photo dissociation of polymeric titanium oxy species via oxidising radicals OH and HO2 formed through Fe3+/Fe2+/H2O Fenton type reactions. Photo dissociation and consequent non-deposition of polymer species in the pores of ilmenite particles cause the chemical reaction between FeTiO3 and HCl acid in stirred solutions to become the rate determining step. The addition of H2O2 to the reaction mixture, in the presence and absence of UV light, further enhances iron leaching rate, confirming the role of radical species.
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