Patent ID: 9399804
Filing Date: 2016-07-26
CPC Classification: C22B,Y02P

Claim Text:
1. A method for recovering scandium, comprising: a leaching step of obtaining a leachate and leach residue by solid-liquid separation under high temperature and high pressure after charging a nickel oxide ore containing scandium, aluminum and chromium into a pressure vessel with sulfuric acid, a neutralization step of obtaining neutralized sediment and a post-neutralization solution by adding a neutralizer to the leachate, a sulfuration step of obtaining nickel sulfide and a post-sulfuration solution by adding a sulfidizing agent to the post-neutralization solution, and separating the nickel sulfide and the post-sulfuration solution, an ion exchange step of obtaining a scandium eluent by bringing the post-sulfuration solution into contact with a chelate resin to adsorb the scandium on the chelate resin, a solvent extraction step of obtaining a stripping liquid by bringing the scandium eluent into contact with an extraction agent, a scandium precipitation step of obtaining precipitates by adding a neutralizer or oxalic acid to the stripping liquid, and a roasting step of obtaining scandium oxide by drying and roasting the precipitates; wherein the chelate resin is a resin having iminodiacetic acid as a functional group, and wherein the ion exchange step comprises: an adsorption step of adsorbing the scandium on the chelate resin by bringing the post-sulfuration solution into contact with the chelate resin, an aluminum removal step of removing aluminum, which has been adsorbed on the chelate resin in the adsorption step, by bringing the chelate resin, which has adsorbed scandium in the adsorption step, into contact with 0.1 N or less sulfuric acid, a scandium elution step of obtaining the scandium eluent by bringing the chelate resin after the aluminum removal step into contact with from 0.3 N or more to less than 3 N sulfuric acid, and a chromium removal step of removing chromium, which has been adsorbed on the chelate resin in the adsorption step, by bringing the chelate resin after the scandium elution step into contact with 3 N or more sulfuric acid.