Slag samples from the oxygen converter and commercial vanadium slag obtained in removing vanadium from low-silicon hot metal are analyzed by up-to-date methods. The number of phases and their chemical composition are investigated, as well as the density and accessibility of the slag. The main components are a spinelide phase (containing more than 97% of the oxidized vanadium) and silicate phases (ortho- and meta-silicates). The slags obtained in removing vanadium from low-silicon hot metal are suitable for subsequent chemical and metallurgical processing.