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

摘要

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°C, NaOH-to-residue 4:1, stirring speed 700 rpm, particle size -74 μm 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.