Determination of Vanadium Valence State in CaO-MgO-Al₂O₃-SiO₂ System By High-Temperature Mass Spectrometry

In the present study, the applicability of the high-temperature mass spectrometric method combined with Knudsen effusion cell for quantifying the valence states of V in the multicomponent system CaO-MgO-Al₂O₃-SiO₂-VO _x up to a maximum temperature of 2050 K (1777 °C) was examined. The valence ratio of V³⁺/V⁴⁺ in slag phase was derived from the partial pressures of VO and VO₂ in the effused vapor phase. The results show good agreement with the literature values obtained by other techniques. A correlation between the valence ratio V³⁺/V⁴⁺ and the oxygen partial pressure as well as basicity was achieved based on the present results and accessed data in the literature. The results of the present study demonstrate that the Knudsen cell-mass spectrometric method can be a very effective tool in estimating the valence ratios for of transition metals in metallurgical slags.