RECOVERING METHOD OF HIGH PURITY INDIUM

摘要

PROBLEM TO BE SOLVED: To provide a method to recover high purity indium with a simple process from an indium-contg. material such as ITO target waste. SOLUTION: An indium-contg. material is dissolved in hydrochloric acid, and an alkali is added to the dissolved liquid to neutralize to obtain a specified pH range from 0.5 to 4 so as to precipitate specified metal ions as hydroxides in the dissolved liquid. Then hydrogen sulfide gas is blown into the liquid to precipitate and remove metal ions as sulfides which are harmful in the succeeding electrolysis process. Then the dissolved liquid is used as an electrolytic source soln. to recover indium metal by electrolysis. By this method, indium of >=99.999% purity can be recovered from an ITO target waste.