Process of vanadium extraction from stone coal vanadium ore by activated sulfuric acid leaching at atmospheric pressure

The method of activated sulfuric acid leaching of stone coal vanadium ore was studied.The effects of the ore particle sizes,sulfuric acid concentration,amount of active agent and catalyst agent,reaction temperature,reaction time and liquid to solid ratio on the leaching rate of vanadium were investigated,respectively.The results show that the optimal conditions of leaching vanadium from stone coal are as follows: stone coal with size less than 74 μm accounting for 80%,sulfuric acid concentration 150 g/L,dosage of active agent(relative to ore) CaF2 60 kg/t,dosage of catalyst R 20 g/L,reaction temperature 90 ℃,reaction time 6 h and liquid to solid ratio(volume/mass,mL/g) 2:1.Under the best condition,the leaching rate of vanadium can be higher than 94%.Under the optimum condition,the two-stage counter-current leaching process was employed,and the dosages of sulfuric acid and active agent CaF2 can be saved.The total recovery rate of vanadium is 86.9% throughout the whole process of two-stage counter-current leaching-solvent extraction-stripping-oxydrolysis.The purity of product V2O5 is higher than 99.5%.