To provide a method for efficiently recovering indium from an acid solution essentially consisting of oxalic acid represented by an etching waste solution.
The method for recovering indium comprises: an adsorption stage where a solution containing indium and oxalic acid is contacted with chitosan so as to adsorb the indium into the chitosan; and a desorption stage where the chitosan adsorbed with the indium is contacted with an acidic aqueous solution comprising hydrochloric acid, sulfuric acid or nitric acid so as to desorb the indium. Regarding the method for recovering indium, from a solution comprising indium and oxalic acid, the indium can be recovered at high efficiency. Therefore, regarding the method for recovering indium, indium can be efficiently adsorbed from an oxalic acid solution such as an etching waste solution exhausted upon the production of an ITO transparent electrode. Particularly, by performing an alkali treatment stage before the desorption stage, the ions of the other metal such as tin coexistent in the etching waste solution and indium are separated, and, only the indium can be recovered.
ROKI TECHNO CO LTD
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