Importance

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Abstract

There is provided a method for recovering indium, the method being capable of recovering indium having a high purity at simple and inexpensive steps in a short time and with a high recovery. After indium containing substances, such as ITO target scraps, are crushed, the crushed substances are ground until the percentage of coarse particles having a larger particle size than a predetermined particle size is not larger than a predetermined percentage. Thereafter, the ground substances are dissolved in an acid, and the solution thus obtained is neutralized with an alkali so that the pH of the solution is 0.5 to 4. Then, the solution is aged at a temperature of 60 to 70.degree. C. for 3 hours or longer to deposit and remove hydroxides of predetermined metal ions in the solution. Then, hydrogen sulfide gas is blown into the solution to deposit and remove sulfides of metal ions which are harmful to electrolysis at the subsequent step, and thereafter, the solution thus obtained is used as an electrolytic solution for electrowinning indium metal to recover indium having a high purity.

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First Claim