Recycling of Spent Indium–Gallium–Zinc Oxide Based on Molten Salt Electrolysis

A facile electrochemical method was used for the first-time recovery of an In–Ga–Zn alloy from a spent indium–gallium–zinc oxide (IGZO). In this work, the molar ratio of In, Ga, and Zn in the alloy is almost the same as that in the initial IGZO after it was electrochemically recovered. For the process, a graphite crucible was used as the cathode to collect the electrolytic products since liquid gallium can be infiltrated into almost all metals to form alloys. The oxygen and carbon contents were only 220 and 130 ppm, respectively, and the yield can reach 98 wt %. The process was simple, efficient, and sustainable and can be extended to large-scale production. Moreover, the obtained alloy was used as raw material for the preparation of oxide composite powders by a coprecipitation method, which can be utilized for preparing the IGZO target. The size of the powder was between 40 and 50 nm, and the distribution of each element was uniform. This article offers a reference for the electrodeoxidation of all gallium-containing oxides. Meanwhile, it also provides a concept for electrolytically recovered alloys directly used as raw materials for the preparation of IGZO.