ITO (ITO)

ITO stands for indium tin oxide, a thin-film ceramic compound (typically 90% indium oxide and 10% tin oxide by weight) that is both electrically conductive and optically transparent. This combination is rare among materials, so ITO has become the default transparent conductive coating for liquid-crystal displays (LCDs), touchscreens, organic light-emitting diode (OLED) panels, and amorphous-silicon solar cells. Every smartphone screen, tablet, laptop display, LCD television, and capacitive touchscreen contains an ITO layer.

Why ITO matters in e-waste: Indium is a metal whose primary production is itself a by-product of zinc and copper refining, with no dedicated indium mines. Annual global primary supply is only 900-1,200 tonnes, and demand from display manufacturing exceeds this — making secondary indium from end-of-life displays a strategically important supply source. Each square metre of LCD glass carries roughly 100-200 milligrams of indium in the ITO layer. A 50-inch flat-panel television contributes about 80-150 mg of indium, a 6-inch smartphone display about 5-8 mg.

Recovery pathway: ITO recovery in India is at an early development stage. The technical sequence involves separating the LCD glass from the polarising film and backlight (a manual or semi-automated dismantling step), crushing the glass to expose the ITO surface, then leaching with hydrochloric or sulphuric acid to dissolve the indium and tin selectively. The resulting indium sulphate or chloride solution is concentrated and electrowon to metallic indium of 99.99% purity. Recovery yields at industrial scale reach 70-85% of contained indium.

Trade-offs and current Indian status: Economic break-even for ITO recovery requires at least 2-5 tonnes of LCD glass per day, equivalent to processing about 5,000-10,000 LCD screens daily. Few Indian e-waste plants reach this scale, so most LCD glass is currently routed to landfill or cement co-processing as inert glass cullet — a wasted opportunity given indium's strategic value. The Rare Metals Recovery initiative under India's Critical Minerals strategy specifically targets domestic ITO processing capacity by 2030.