Theoretical application and factors influencing casting settlement of FeV50 alloy

The process of separation of slag and alloy and distribution of vanadium in casting slag during the casting process of multiperiod FeV50 preparation were analyzed using the principle of infinite fluid gravitational settling. The effects of slag viscosity, particle size, casting temperature, molten-slag thickness, and insulation system on total vanadium (TV) content in slag were investigated. The analysis demonstrates that vanadium mainly comprises vanadium oxide and incompletely deposited primary ferrovanadium alloy in the casting slag. The sedimentation rate of settlement alloy increases with an increase in the particle size and decreases with an increase in the slag viscosity. The dropping time of FeV50 alloy and floating time of molten slag is 24.9 and 1.2 min, respectively, when the casting conditions are as follows-casting temperature:1850℃, slag layer thickness:50 mm, particle size:100 μm, and slag composition mass fraction:65.2% Al₂O₃, 15.5% CaO, 14.6% MgO, 1.9% Fe₂O₃, and 0.9% SiO₂. Through optimization experiments, the average vanadium mass content in the slag is reduced from 1.39% to 0.58% for the following casting conditions-slag layer thickness:35 mm, casting temperature:1900℃, slag component:60%-65% Al₂O₃, 15%-20% CaO, 9%-15% MgO; and casting insulation thickness:9 cm.