Abstract
In order to develop a hydrometallurgical recycling process for an indium-tin-oxide (ITO) target, it is necessary to remove Sn(IV) ions from solutions containing Sn(IV) and In(III). In this study, therefore, the removal of Sn(IV) ions by galvanostatic electrolysis was examined. Polarization measurements were carried out under a nitrogen atmosphere. In the Sn(IV) solution, the current begins to increase at a cathode potential of −0.26 V vs. SHE, and keeps on increasing with a negative shift of the cathode potential. In the In(III) solution, the current begins to increase at a cathode potential of −0.43 V vs. SHE. In the galvanostatic electrolysis, 52% of Sn(IV) ions were removed and electrodeposited as metallic tin containing less than 1% indium; the current efficiency was close to 100%. After further electrolysis, indium was codeposited with tin.
