Substance flow analysis of indium for flat panel displays in Japan

Substance flow analysis (SFA) of indium has been conducted in this study. The purpose of this study is to identify the relevant issues for the development of an efficient indium recycling system by performing SFA of indium supplied for indium-tin oxide (ITO) processing as transparent electrodes, which accounts for 86.9% of the total indium demand. In this study, as part of the development of substance and material flow data, (1) data on the flow of indium was collected and reviewed, (2) the amount of dissipated indium associated with the production of flat-panel displays (FPDs) were estimated and (3) its environmental impact was also assessed. The major conclusions are (a) 470 t-In is used in ITO for transparent electrodes, out of which 220 t-In is dissipated or potentially dissipated in Japan, and (b) 220 t-In of dissipated indium is equivalent to 11.4 TJ of energy consumption, 0.5 × 10³ t of CO₂ emissions, and 1.0 × 10⁶ t of Total Materials Requirement (TMR).