To clarify the possibility of substituting part of O2 with CO2 during the vanadium extraction process in converter, the oxidation of vanadiumTo clarify the possibility of substituting part of O2 with CO2 during the vanadium extraction process in converter, the oxidation of vanadium-containing hot metal is carried out on a laboratory-experimental scale by using CO2-O2 gas mixture as oxidizer. The results show that both the oxidized carbon and oxidation rate of carbon in the hot metal are increased with increasing proportion of CO2 in the gas mixture, while the amount of oxidized vanadium decreases with increasing proportion of CO2. The amounts of oxidized vanadium and carbon are comparable when the CO2 proportion is 0 and 20% (volume percentage) respectively. The amount of oxidized carbon and vanadium is 34.56% and 96.85% respectively when the CO2 proportion is 0, and the amount of oxidized carbon and vanadium is 36.83% and 93.29% respectively when the CO2 proportion is 20%. The ratio of vanadium oxidation amount to carbon oxidation amount (ΔV/ΔC) is adopted to evaluate the effectiveness of extracting vanadium. The ΔV/ΔC is 5.96 when the CO2 proportion is 20%, and the ΔV/ΔC are all below 3.8 when the CO2 proportion is 40%, 60% and 80%. The vanadium oxidation rate increases in the early reaction stage and decreases in the late reaction stage with increasing of CO2 concentration.