SCANDIUM RECOVERY METHOD

摘要

In order to recover high-quality scandium from nickel oxide ores efficiently, this method comprises: a leaching step (S1) for feeding Ni oxide ores and sulfuric acid into a pressure vessel, and subjecting the mixture to solid-liquid separation to form a leachate and a leach residue; a neutralization step (S2) for adding a neutralizing agent to the leachate, and thus forming a neutralization sediment and a post-neutralization fluid; a sulfurization step (S3) for adding a sulfurizing agent to the post-neutralization fluid, and separating the obtained mixture into Ni sulfide and a post-sulfurization fluid; an ion-exchange step (S4) for bringing the post-sulfurization fluid into contact with a chelating resin, making Sc adsorbed on the chelating resin, and forming an Sc eluent; a solvent extraction step (S6) for bringing the Sc eluent into contact with an extracting agent, adding a back-extraction agent to the extract, and thus forming back-extracted matter; and a roasting step (S8) for roasting the back-extracted matter, and thus forming Sc oxide. It is preferable that the method further includes, after the ion exchange step (S4), a concentration step (S5) for forming a sediment from the Sc eluent and dissolving the sediment in an acid, and includes, after the solvent extraction step (S6), an Sc precipitation step (S7) for dissolving the back-extracted matter in hydrochloric acid, adding oxalic acid to the obtained solution, and thus forming Sc oxalate crystals.