Selective leaching of vanadium from vanadium slag using organic acids

Abstract: Large amounts of vanadium bearing slags are produced during steel making and discarded to the environment. Bioleaching has proved that it is an environmentally friendly route which has been lately used for recovery of metals. The leaching of vanadium from a roasted slag was studied using gluconic, citric and oxalic acids. The vanadium slag was roasted at 900oC in presence of Na2CO3 prior to leaching. The effect of acid concentration, solid/liquid ratio, particles size and temperature were investigated. It was observed that at a concentration of 150mM for gluconic acid and 100mM of citric and oxalic acid, 2% of S/L ratio, -38μm and temperature of 45oC, 91, 86 and 81% of vanadium were recovered from gluconic, citric and oxalic acid respectively. Recovery of vanadium using gluconic acid is affected more by the acid concentration compared to citric and oxalic acids. The solid/ liquid ratio as well as the particle size increase have a negative effect on the recovery of each acid and the temperature increase allows to enhance the recovery