Mechanism on the Separation of Vanadium and Titanium from Vanadium Slag by Roasting with Ammonium Sulfate

The technology of simultaneously recovering V and Ti from vanadium slag via ammonium salt roasting has proven to be an efficient route. However, due the phase stability complex chemical composition slag, intermediate materials containing Fe, V, Mn are difficult characterized critically. This work aims investigate decomposition transformation during roasting, using a combination FT-IR, XRD, XPS SEM techniques. It was found that lattice structure Fe-contained spinel would transformed FeV2O4 Fe2+VnFe2?nO4 (0 < n 2) directly in air. there is no obvious change for Ti-contained Mn-contained spinel. Using NH4HSO4 (ABS) as additive N2 atmosphere, those spinels decomposed into various sulfate salts. Meanwhile, when roasted with air, part Fe(II) (NH4)2Fe(SO4)2 transferred Fe(III), but V(III), Ti(IV) Mn(II) salts remain same valance state. Ultimately, about 88% 81% were recovered, at 663.15 K 1:5 ratio slag-to-NH4HSO4 followed by 8 vol.% H2SO4 leaching.