Direct Vanadium Alloying of Liquid Steel with Self‐Reduction Vanadium Slag Briquette

Herein, a green and innovative direct alloying technology of liquid steel with self‐reduction vanadium slag briquette is proposed. This method with resource‐conserving, energy‐saving, and environment‐friendly, provides an alternative of the compact process for producing vanadium‐bearing steel. Thermodynamic and experimental investigations are carried out to illustrate the selective reduction tendency of oxide components in vanadium slag, recovery yield of vanadium and reaction mechanism during the direct alloying process. The reduction order of oxide components in vanadium slag briquette is FeO, Cr 2 O 3 , V 2 O 3 , and MnO, and after 20 min alloying time, the mass fraction of [V] in liquid steel climbs dramatically up to 0.56%. With increasing alloying temperature from 1520 to 1600 °C, the recovery yield of vanadium increases from 70.23% to 84.54%, and the highest vanadium recovery yield could reach 90.04% under the optimal conditions, indicating that higher temperature is essential to enhance self‐reduction reaction and mass transfer in liquid steel. The direct alloying process is controlled by the diffusion of vanadium element from the reaction interface into liquid steel through the slag‐metal boundary layer. In addition, smaller‐size vanadium slag briquette and intensified mixing of liquid steel are recommended to ensure rapid alloying and high vanadium recovery in applicable industrial production.