Thermodynamic behavior of vanadium and chromium in “FeO”‐SiO ₂ ‐CaO‐V ₂ O ₃ ‐VO ₂ ‐Cr ₂ O ₃ system

Abstract The vanadium and chromium have an extremely high potential for application in ceramics. High‐chromium vanadium slag, a by‐product of the smelting of high‐chromium vanadium‐titanium magnetite, contains significant vanadium and chromium resources. However, the lack of thermodynamic studies on oxide systems containing VO x and CrO x has limited their efficient utilization. In this study, the phase equilibrium experiments of the “FeO”‐SiO 2 ‐CaO‐V 2 O 3 ‐VO 2 ‐Cr 2 O 3 system were carried out at 1400°C under P O2 = 10 −10 atm, and the corresponding isothermal section diagram was constructed. The results showed that vanadium and chromium were mainly crystallized as Fe(V,Cr) 2 O 4 and (Fe,V,Cr) 2 O 3 , and Fe(V,Cr) 2 O 4 had higher crystallization ability. Furthermore, the influence of basicity, “FeO” content, and temperature on the thermodynamic behavior of vanadium and chromium was further investigated in the coexistence region of Fe(V,Cr) 2 O 4 +Liquid. It was found that the crystallization of vanadium and chromium was inhibited with the decreasing “FeO” content; the increase in basicity inhibited the crystallization of vanadium but facilitated the crystallization of chromium; the decrease in temperature significantly enhanced the crystallization of vanadium but had a weaker effect on the crystallization of chromium. This study provides the basic thermodynamic data for the efficient utilization of high‐chromium vanadium slag.