Zinc: Extraction

Why zinc and lead come from the same mines

Zinc is mined mainly as sphalerite, a zinc sulfide, from sediment-hosted and volcanic-hosted deposits that usually also carry lead and silver. Lead and zinc are classic co-products, often pulled from the same mine (Tilton & Guzmán). Ore is crushed and floated into a concentrate, which smelters roast and then leach and electrowin into Special High Grade metal. The ore also carries smaller metals: cadmium, indium, germanium, gallium and thallium are recovered, or not, as by-products of zinc refining (Nassar et al.). US drilling at the idled Middle Tennessee mines in 2025 targeted germanium and gallium as well as zinc.

Zinc comes mainly from sulphide ores of zinc and lead, often with silver. Ore is mined, mostly underground, and floated into concentrate at the mine. Concentrate is sold to smelters, many of them in China, Korea, Europe, Canada and India, which roast it to oxide, leach it in sulphuric acid, purify the solution and electrowin high-grade zinc. A smaller share is smelted in blast furnaces with lead. Secondary zinc is recovered from steelmaking dust and galvanising residues. Because concentrate carries lead, silver and minor metals, by-product credits shape both mine and smelter economics.

Methods compared

How each method works

Sulphide ore is drilled, blasted and hauled, then crushed, ground and floated. Separate zinc and lead concentrates are produced, with silver reporting mostly to the lead concentrate. Concentrate is trucked, railed or shipped to smelters, many of them owned by other firms.

Lead and silver credits can push net costs below zero, but grades decline as mines age, as at Red Dog.

Concentrate is roasted to zinc oxide, releasing sulphur dioxide that is converted to sulphuric acid. The calcine is leached in acid, iron and impurities are removed, and pure zinc is plated onto cathodes, stripped, melted and cast into Special High Grade ingots. Integrated miners such as Hindustan Zinc capture the full margin.

Makes the high-purity grade the LME trades, but needs large amounts of electricity, which closed some European capacity when power prices spiked.

Dust from electric arc steel furnaces, which carries zinc from galvanised scrap, is processed into crude zinc oxide and fed to smelters. Galvanising dross and ash, brass scrap and die-cast scrap are remelted or refined.

Recovers zinc that would otherwise be hazardous waste, but much zinc is dissipated in coatings and chemicals and cannot be recovered.

Share produced as a by-product

Who does it: global

Who does it: India

India mined about 870 kt of zinc in 2025, fifth in the world, with 10 Mt of reserves (USGS). Hindustan Zinc is almost the only primary producer and held about 77% of the domestic primary zinc market in FY2025 (HZL IR FY2024-25); the rest is imported.