| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for efficiently collecting crude indium having a purity suitable for electrolytic refining from a scrap of an ITO target at a high yield. <P>SOLUTION: This collecting method includes the following steps (α) to (δ). The step (α) includes: leaching a ground scrap of the ITO target with hydrochloric acid, and then separating an insoluble residue to obtain a leachate. The step (β) includes: adding zinc dust to the leachate in an amount of 2 to 5 equivalent weight with respect to an amount of tin in the leachate by stoichiometry in a substitutional reduction reaction, producing a suspension of spongy indium (1) and a solid content of reductively precipitated impurity metals which are nobler than indium, and separating and collecting the spongy indium (1) to obtain an aqueous solution of indium chloride. The step (γ) includes: bringing aluminum into contact with the aqueous solution of indium chloride to obtain spongy indium (2). The step (δ) includes: mixing the spongy indium (1) and the spongy indium (2) with sodium hydroxide, and heating and melting them to obtain the crude indium. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
