Study of Scandium Pre-enrichment from Red Mud Leached by Hydrochloric Acid

The effects of concentration of hydrochloric acid,leaching time and ratio of liquid to solid(L/S)on leaching rate of scandium from red mud of Bayer process were investigated.The results show that leaching rate of scandium is 96.63% under the optimum conditions including hydrochloric acid concentration of 7mol/L,temperature of 80 ℃,leaching time of 90 min,and L/S=8.0.The extraction rate of scandium reaches 97.99% with P204 as extracting agent.Scandium-rich organic phase is cleaned by acid solution,neutralized with NaOH solution and then filtrated and dried.The mass fraction of scandium in solid is 2.09% with total scandium recovery efficiency of 97% above and enriched time of 328 compared with that in red mud.