Iron(II) oxidation by SO2/O2 for use in uranium leaching

A review of acid leaching of uraninite

“…Previous studies conducted on natural and/or synthetic UO 2 dissolution have shown that the ferric ion oxidises the insoluble UO 2 to its soluble uranyl (UO 2 2+ ) form, with the additional oxidant re-converting the ferrous ion back to ferric ion (Arden and Beaumont, 1950;Laxen, 1965Laxen, , 1971. The oxidising agents most commonly used in uraninite leaching to convert ferrous ions to ferric ions are manganese dioxide (MnO 2 as pyrolusite) (Ho and Ring, 2007;Merritt, 1971); oxygen (Bovey and Stewart, 1979), hydrogen peroxide (DeVries, 1984;Lucas et al, 1983); Caro's acid (H 2 SO 5 ) (Lucas et al, 1983;Venter and Boylett, 2009); sulfur dioxide/air (SO 2 / air) (Ford, 1993;Ho and Quan, 2007); and sodium chlorate (Merritt, 1971). An evaluation of various oxidants used in acid leaching of uranium can be found in Venter and Boylett (2009).…”