Analysis of V and Cr with various valence states in FeO-SiO2-MnO-TiO2-VOx-MgO-CrOx system by XPS method

The valence states of vanadium and chromium in FeO-SiO 2 -MnO-TiO 2 -VO x -MgO-CrO x system were investigated by X-ray photoelectron spectroscopy (XPS). The results indicate that Cr(III) and V(III) are the dominant valence states in this slag system. The fractions of Cr(III) and V(III) are more than 93% and 92% respectively. The fractions of Cr(II) and V(IV) are in the range of 3% ∼ 6%. The fractions of Cr(VI) and V(V) are below 0.9% and 1.9% respectively. Oxygen potential Log(PO 2 ) has great influence on the valence states of Cr and V. Cr 2 O 3 content has little influence on the valence state of V. Similarly, V 2 O 3 content has little influence on the valence state of Cr. The contents of toxic hexavalent Cr(VI) and pentavalent V(V) can be reduced by decreasing Log(PO 2 ) or decreasing Cr 2 O 3 content and V 2 O 3 content.