Recovery and Separation of Vanadium and Chromium by Two-Step Alkaline Leaching Enhanced with an Electric Field and H(2)O(2)

[Image: see text] This paper focused on the treatment of vanadium–chromium reducing residue with a two-step alkaline leaching process: electro-oxidation leaching of vanadium and H(2)O(2) as well as oxidation leaching of chromium in an alkaline medium. The effects of experimental parameters on the leaching performance of vanadium and chromium were investigated. The experimental data showed that in the first alkaline leaching in stage I, the leaching efficiency of vanadium reached up to 95.32% under optimal conditions, while most of the chromium could not leach out (about 4% of chromium was leached out). Chromium was easily oxidized to high valence (CrO(4)(2–)) with H(2)O(2) in the second alkaline leaching stage II. Under optimal conditions, 96.24% chromium was leached out.