A novel method of leaching vanadium from extracted vanadium residue using sodium sub-molten salt medium

Leaching of an extracted vanadium residue in sodium sub-molten salt medium was investigated. The significant effects of reaction temperature, particle size of residue, reaction time and NaOH-to-residue mass ratio on vanadium extraction were studied. By the orthogonal experiment study, it can be concluded that the impact order of factors is T-r > t > R according to the significance to the leaching process. Under conditions of reaction temperature 170 degrees C, NaOH-to-residue 4:1, stirring speed 700 rpm, particle size -74 mu m and reaction time around 180 min, leaching efficiency of vanadium obtained is higher than 90%. And, the leaching process of vanadium, with activation energy 27.69 kJ.mol(-1), is controlled by the chemical reaction-controlled as the following rate equation. ln(1-x) = -k