Extraction of Vanadium from CaO–SiO₂–MgO–Al₂O₃ Slags Based on Vaporization of Vanadium Pentoxide

Vanadium is an important micro‐alloying element for various steel grades. Consequently, it is also present in the slags used in the production of those grades. During steelmaking, the vanadium vaporization from the slag is not desirable, as it increases vanadium consumption and at the same time releases toxic vapors of its higher oxides. However, the recovery of vanadium from the slag after the processing is worthwhile. In oxidic form as vanadium pentoxide (V 2 O 5 ), vanadium can be extracted from the slag. In this research, the vaporization behavior of vanadium from CaO–SiO 2 –MgO–Al 2 O 3 industrial slag is investigated at 1873 K. The effect of different process parameters, e.g., the pressure in the furnace chamber, the duration of the oxygen treatment of the slag, and the oxygen flow rate, is considered. The effect of P 2 O 5 and Fe 2 O 3 addition on the extraction of vanadium is studied. It is possible to induce formation of V 2 O 5 gas bubbles in the slag due to the oxidation of vanadium. Thus, vanadium respectively V 2 O 5 is extracted from the slag.