Indium: Extraction
How a few parts per million become a screen coating
What this tab covers How it is mined, drilled or grown, and processed into a tradeable form: the main methods compared, their unit economics, by-products, and the companies that do this work globally and in India.Indium is recovered mainly from sphalerite, the zinc sulphide mineral. Zinc deposits that yield it contain from under 1 to 100 parts per million, far too little to mine for indium alone. Smelters collect indium in residues and dusts, then leach and refine it to 99.99% metal. Smaller amounts come from tin and copper ores. Recovery efficiencies for some companion metals can be as low as 10%, so much indium in mined zinc is never captured (Nassar et al., pdf p. 7). Companionality is about 95%.
Indium is a by-product of zinc. A zinc smelter that installs a recovery circuit can extract indium from its residues; one that does not sends it to waste. Primary output therefore depends on which smelters choose to recover it, mostly in China and Korea. A large second loop runs through recycling of manufacturing scrap: ITO sputtering leaves most target material unused, and Japanese and Korean refiners recover it. Recovery from copper and tin ores is technically possible but rarely economic (USGS 2026).
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| By-product of zinc smelting (residue leaching and solvent extraction) | almost all primary indium (Tilton and Guzman 2016; USGS 2026) | China 760 t, Korea 180 t, Japan 65 t, Canada 40 t in 2025 (USGS); world capacity 1,700 t | Not published; USGS notes recovery from most copper and tin deposits is uneconomic | zinc host; germanium, cadmium, lead, silver | n/a |
| Recycling of ITO sputtering targets and production scrap | not published; USGS lacks data on quantities recovered | n/a | end-of-life recycling input rate about 1% (EU CRM 2023); most recycling is of new manufacturing scrap | tin | n/a |
| Recovery from stocks and tailings | small and irregular | Fanya stock about 3,609-3,629 t, about five to six years of supply (Fastmarkets 2017; Lipmann Walton 2020) | n/a | n/a | Indicative: the 2019 court auction opened at 790.4 yuan/kg (about $113/kg) and failed to sell (Lipmann Walton 2020) |
How each method works
By-product of zinc smelting (residue leaching and solvent extraction)Indium in zinc concentrate concentrates in leach residues and fumes. These are re-leached with acid, indium is pulled out by solvent extraction, cemented on zinc or aluminium plates to crude metal, then electrorefined. The same plants often recover germanium and cadmium.
Low marginal cost where circuits exist; supply cannot follow demand faster than circuits are built.
USGS MCS 2026; Tilton and Guzman (2016), Mineral Economics and Policy Recycling of ITO sputtering targets and production scrapSpent targets, sputtering-chamber scrap and etching waste are dissolved and refined back to metal, then remade into targets. Japan and Korea dominate this loop.
Adds supply without new mining; almost nothing comes back from old screens.
USGS MCS 2026; EU CRM 2023 Recovery from stocks and tailingsSome producers recover indium from old tailings and slags on a limited scale (USGS Circular 1365). The largest above-ground stock is the 3,600 t held in the warehouses of China's collapsed Fanya exchange, whose sale has been attempted by court auction.
A large overhang that caps price rallies; quality and actual tonnage are uncertain.
USGS Circular 1365 (2010); Fastmarkets (2017, 2018); Lipmann Walton & Co (2020) Unit economics are indicative ranges from the sources named; costs vary widely by deposit, region and year.By-product supply
Companionality is about 95%: indium is recovered almost entirely from zinc. Primary indium output rose 1,675% between 1975 and 2012 while zinc grew only 231% (Nassar et al. 2015), because smelters added recovery circuits as display demand boomed. That route has limits. Each new circuit takes years, zinc output does not respond to indium prices, and in 2017 China's environmental crackdown on zinc mines cut indium output by about 20% (Fastmarkets). Supply is price-inelastic in the short run.
Share produced as a by-product
About 95% of primary supply comes as a by-product of zinc (Nassar, Graedel & Harper 2015, approximate).Who does it: global
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Korea Zinc not published; Korea Zinc is the main Korean producer and Korea supplied 25% of US imports 2021-24 | South Korea | zinc smelting with indium recovery (Onsan) | not published | 2025 | USGS MCS 2026 (Korea output 180 t, capacity 310 t); company volume not published |
| Chinese zinc smelters (country total) operator volumes not published; China had 70% of world output | China | indium recovery at zinc and lead smelters | 760 t In (country refinery output) | 2025 | USGS MCS 2026 |
| Teck Resources (Trail Operations) not published | Canada | zinc-lead smelting with indium recovery | not published | 2025 | USGS MCS 2026 (Canada output 40 t) |
| Nyrstar (Auby smelter, Trafigura group) not published | France | zinc smelting with indium recovery | not published | 2025 | USGS MCS 2026 (France output 21 t, capacity 70 t) |
| Umicore not published | Belgium | indium refining and recycling | not published | 2025 | USGS MCS 2026 (Belgium output 19 t) |
| Japanese refiners and ITO recyclers (country total) operator volumes not published | Japan | zinc smelting, ITO target making and recycling | 65 t In (country refinery output) | 2025 | USGS MCS 2026 |
Who does it: India
India has no reported indium refining; USGS lists no Indian output. Indium is on India's 2023 critical list, and the country imports metal and ITO targets for electronics. Hindustan Zinc's FY2025 integrated report reports no indium recovery.