Electrolytic Zinc (SHG/SSHG)

Korea Zinc Co., Ltd. (Seoul; KRX: 010130; ~$9B revenue) is the world's largest single-site zinc, lead, and silver smelter operator and the world's largest non-Chinese indium refiner. Indium is recovered as a byproduct at its Onsan smelter in Ulsan, South Korea — the only facility in Korea with an indium processing line. Korea Zinc produces ~150 tonnes of indium annually at 99.999% purity (vacuum-packed 5-kg bars), meeting roughly 11% of global demand outside China. About 90% of Korea Zinc's indium output is exported to the US, Japan, and Taiwan — making it the primary indium supplier for US and Taiwanese display/semiconductor manufacturers seeking non-Chinese supply. The Onsan smelter also produces gallium and antimony; Korea Zinc has invested heavily to diversify into critical minerals as a strategic counterweight to Chinese dominance.

Swiss-UK commodity trading and mining company (LSE: GLEN, HQ Baar, Zug Switzerland; ~$250B revenue); world's largest zinc producer by combined mining and trading operations. Glencore's zinc mining assets include: Mount Isa (Queensland Australia — one of the world's largest underground zinc-lead-silver mines), Lady Loretta (Queensland), Antamina (Peru — joint venture), and multiple other mines. Glencore also markets zinc concentrate from third-party miners through its commodity trading arm. Glencore's business model — combining mine ownership with commodity trading intelligence — gives it unique market positioning: it both produces zinc and trades the global zinc supply, enabling it to influence prices and allocations in ways that pure miners or pure traders cannot. Glencore is also the world's largest coal exporter and a major cobalt producer (Katanga, DRC) — the same Swiss trading house that mines zinc for galvanizing irrigation pipes also mines the cobalt in EV batteries and the coal that generates electricity for steel mills that process galvanized steel.

Swedish mining and smelting company (NASDAQ OMX: BOL, HQ Stockholm); major European zinc producer operating Kokkola smelter (Finland, 315,000 t/yr — one of Europe's largest) and Odda smelter (Norway). Mines zinc at Garpenberg (Sweden, Europe's largest zinc mine), Tara (Ireland), and Kristineberg (Sweden). Boliden is the primary Nordic zinc supplier for European battery assemblers. Also produces copper, lead, gold, silver. Boliden is the company that caused the Aznalcóllar mine disaster in Spain (1998) — one of Europe's worst environmental disasters — and decades later remains one of Europe's most important metals producers.

Chinese zinc and germanium producer (SHEX: 600497, HQ Kunming, Yunnan); major integrated zinc miner and smelter in China. Also one of the world's largest germanium producers — germanium is a critical semiconductor material used in fiber optic cables, infrared optics, and solar cells. Yunnan Chihong's position in germanium (a byproduct of zinc smelting) means the same Chinese company that makes zinc for alkaline batteries also produces a large fraction of the world's germanium for telecommunications and defense optics.

Nyrstar NV (Balen, Belgium; subsidiary of Trafigura since 2019) is one of the world's largest zinc smelting groups, operating multiple European zinc smelters that collectively produce indium as a byproduct. Nyrstar's Critical Minerals Recovery program recovers indium across three European smelters: Balen/Pelt (Belgium), Budel (Netherlands), and Auby (France). Nyrstar's Budel zinc smelter — the largest zinc smelter in the Netherlands — was placed on care and maintenance in January 2024 due to high European energy costs, then restarted at reduced capacity in May 2024. Balen (Belgium) is the largest-capacity single Nyrstar site. Nyrstar's combined indium output is modest relative to Asian producers; however, it represents critical European indium supply for domestic ITO manufacturers.