The Making of
Zinc
Zinc spends its working life protecting steel by corroding in its place. Winning the pure metal is the hard part. Heat its ore and the zinc boils away as a vapour that wants to burn straight back to powder, so nearly all of it is now made not with fire but with electricity.
Every figure on this page is sourced. The notes at the end say where each one comes from.
If it is steel and it lives outdoors, zinc is probably why it hasn’t rusted away.
The journey
From rock to coating, the whole arc
Making zinc means turning a lean sulphide rock into pure metal without letting the metal boil away. The ore is crushed and floated into a rich concentrate, roasted to an oxide, then (for more than nine tonnes in ten) dissolved in acid and plated out with an electric current rather than reduced in a furnace. Tap a stage to follow it through.
Three inputs, and the third is the expensive one
Zinc metal is made from a sulphide rock, an acid, and a great deal of electricity. The rock is cheap and common; the electricity is what you are really paying for.
Only three things go into making zinc, and they are wildly unequal in cost. The mineral is abundant, the acid is largely made on site from the ore itself, and the electricity, the input that actually pulls the metal out of solution, is the one that shapes the whole industry.
Sphalerite: zinc sulphide (ZnS)
Almost all zinc starts as sphalerite, a zinc-sulphide mineral scattered widely through the earth’s crust. As mined, the rock is far too lean to smelt, typically 5 to 15% zinc, so it is crushed, ground, and floated in water until the zinc-bearing grains separate out as a concentrate of about 55% zinc, carrying a little copper, lead, and iron with it. That concentration happens at the mine, because it is cheaper to move a rich concentrate than a mountain of waste rock. (Metalpedia; grades are route-typical.)
Sulphuric acid
The electrolytic route runs on acid. It dissolves the roasted ore, and the same acid is regenerated in the electrical cell and pumped back to do it again. Much of that acid is a by-product of the roasting step itself: the sulphur driven off the ore becomes sulphur dioxide, and that is turned into sulphuric acid (the same contact-process acid, made and consumed on site) rather than released. (Metalpedia; EPA.)
Electricity
The defining ingredient. Pulling zinc out of solution with an electric current, called electrowinning, takes roughly 3,900 kWh for every tonne of metal, and the electrolysis step alone accounts for about a third of all the energy a zinc smelter uses. This is why a zinc plant is really an electricity-into-metal machine, and why the price of power shapes the industry as much as the price of ore. The zinc plates onto aluminium cathode sheets and is stripped off every day or two. (Metalpedia; IZA.)
Two ways out of the ore, electricity or caught fire
Both routes begin the same way, by roasting the ore to an oxide. They part at the next step: one dissolves that oxide and plates the metal out with electricity; the other reduces it with carbon at a heat so high the zinc comes off as a gas that has to be caught before it re-oxidises.
Every route shares a first step: roasting. The concentrate is burned in air so that its zinc sulphide becomes a powdery zinc oxide (the industry calls it “zinc calcine”) and its sulphur leaves as sulphur dioxide, bound for the acid plant. What happens to that calcine next is the whole story.
Roast, leach, electrowin
Why make a metal with electricity instead of fire? Because fire boils it away. Because heating zinc oxide hot enough to reduce it would boil the metal off, the modern industry mostly refuses to reduce it with heat at all. Instead it dissolves the calcine in sulphuric acid, a step called leaching, to make a zinc-sulphate solution. That solution is cleaned by a neat trick: adding zinc dust makes the dissolved copper, cadmium, cobalt, and nickel drop out as solids, because zinc is reactive enough to shove them out of solution and take their place.
The cleaned solution then goes into electrical cells, where a current drives the zinc onto aluminium sheets and oxygen off at the other electrode, rebuilding the sulphuric acid, which returns to the leach. Every day or two the sheets are lifted out and the zinc peeled off. Melt those peelings and cast them and you have special high-grade zinc: 99.995% pure. The cells barely run warm, around 30–35 °C, which is the point: this is chemistry done with electricity, not heat.
Catching the vapour
The older route does reduce the oxide with carbon, and pays the price the electrical route avoids. To strip the oxygen off, the furnace has to reach around 1,400 °C, far above zinc’s 907 °C boiling point, so the metal emerges not as a liquid but as a vapour mixed with furnace gas. Let it cool slowly and it simply burns back to oxide; the whole art is to chill it fast enough to catch it. The classic solution is brutal and clever: spray the hot gas with a shower of molten lead droplets that quench the zinc vapour in an instant and carry it down as liquid, to be separated from the lead as it cools.
It works, but it costs. This is an energy-hungry way to make zinc, and it yields a metal only about 98% pure, fine for galvanising but too dirty for the die-casting alloys that need 99.995% zinc, so it must be refined further. As electricity displaced fire, the fire route retreated: the blast-furnace (Imperial Smelting) version now runs in only a few countries: China, India, Japan, and Poland. (Metalpedia.)
One metal, four working lives
Most zinc never becomes a solid object you would recognise. It is a coating, an alloying partner, or a chemical, and by far its biggest job is to be a skin that gives itself up to save the steel underneath.
Four families cover almost all of it. Only the first is a use most people would picture, and it is by far the largest.
A coating: galvanising
Dip steel into molten zinc, or spray it on, and the steel gains a skin that does two jobs at once. It is a barrier; and, because zinc is the more reactive metal, it is a sacrifice: at a scratch or a cut edge, the zinc corrodes in the steel’s place rather than letting rust creep under the coating. That second property, cathodic protection, is why a galvanised part keeps protecting itself even when damaged, and why about 60% of all zinc ends its life as a coating on someone else’s metal.
Die-casting and brass
Zinc’s low 419 °C melting point, well below aluminium’s 660 °C and far below copper’s 1,085 °C, makes it the metal of choice for die-casting: molten zinc fills fine, complex moulds crisply, at low energy and with long die life, giving the small precise parts inside locks, cars, and appliances. Alloyed the other way, with copper, zinc makes brass, harder and more workable than either parent.
Rolled zinc
Rolled into sheet, zinc roofs and clads buildings, weathering to a soft grey that can last a century. It is the visible face of the metal, the one use where you are looking straight at the zinc itself rather than at the steel or brass it is hiding inside.
Zinc oxide
A large slice of zinc never becomes metal at all: zinc oxide, a fine white powder, goes into rubber and tyres, paints, ceramics, sunscreen, and (as a plant and animal micronutrient) into fertilisers and animal feed. These dispersive chemical uses are the ones that essentially never come back for recycling.
First use of refined zinc
Galvanising is sourced precisely; the rest is shown in rough order, not to exact shares.
Galvanising is about 57% of ~14 Mt of refined first use (IZA), rising to ~60% of all zinc produced on the IZA 2050 scenario. The remaining ~40% (die-casting alloys, brass and bronze, rolled zinc, and zinc-oxide chemicals) is shown in order rather than by precise share, because the folder sources give the galvanising figure but not an audited split of the rest.
About thirteen million tonnes a year, and where it comes from
The world mines and refines roughly 13 million tonnes of zinc a year. China leads both the digging and the smelting; the places that mine the ore and the places that turn it into metal are often not the same places at all.
Zinc is the fourth most-used metal, after iron, aluminium, and copper. In 2025, world mine production was an estimated 13.0 million tonnes of zinc-in-concentrate, and global refined-metal production about 13.8 million tonnes. Those are two different measures (ore content versus finished metal), which is why the figures don’t line up exactly. (USGS, 2026; refined forecast ILZSG.)
Top mine producers, 2025e
Zinc content of concentrate, in millions of tonnes. China alone mines close to a third of the world’s ore. (USGS, 2026.)
Dig here, smelt there
Zinc is a good example of a material whose map splits in two. The United States mines a lot of ore, worth about $2.2 billion in 2025, yet exports most of that concentrate to foreign smelters and imports refined metal to use, relying on imports for roughly three-quarters of the refined zinc it consumes. The ore and the metal travel in opposite directions. (USGS, 2026; US figures, regional.)
The supply chain, using the US case
Each step happens in a different place; the point of the diagram is the direction of travel, not the tonnages.
Dug in five states (for example Red Dog, Alaska) and mostly shipped out as concentrate.
Refined into metal abroad; China dominates new smelting capacity.
Refined zinc coats steel for construction and vehicles.
The problem isn’t running out, it’s the power bill and the loop
Zinc’s sustainability story is not scarcity. There is plenty of ore and a growing “urban mine” of zinc already in use. The pressure sits on the electricity the electrolytic route drinks, and on closing the recycling loop for a metal that spends decades locked inside buildings before it comes back.
Not a shortage
It is tempting to divide reserves by annual demand and predict a date when zinc runs out; the industry’s own data says that misreads the problem. Refined zinc production rose about 80% between 1990 and 2019, yet the reserve lifetime barely moved, because exploration keeps converting resource into reserve. Beyond today’s ~240-million-tonne reserves lie identified resources of roughly 1.9 billion tonnes, and far more that is geologically present. Scarcity is not the binding constraint. (USGS, 2026; IZA.)
The energy question
The real cost is power. Because the dominant route makes zinc by electrowinning, each tonne carries roughly 3,900 kWh of electricity, and the carbon footprint of that tonne depends heavily on whether the grid behind it burns coal or runs on renewables. Decarbonising zinc is therefore less about changing the chemistry and more about changing the electricity that drives it, which ties zinc’s emissions directly to the cleanliness of the power system around each smelter.
Closing the loop: the urban mine
Zinc can be melted and reused indefinitely without losing its qualities, but much of it is hard to get back soon: locked into galvanised beams and zinc roofs, it may not return for 30 to 100 years. In 2020 about 234 million tonnes of zinc were already in use, an “urban mine” roughly the size of the world’s proven reserves, and one projected to double by 2050 as today’s buildings age into scrap. (IZA, 2022; modelling Fraunhofer ISI.)
of zinc were already in use in 2020, an urban mine about as large as the world’s reserves, and set to double by 2050. Secondary sources supplied about 4.3 Mt of zinc that year, and roughly a quarter of the zinc going into new products now comes from recycled material. The share recovered from products at the end of their lives is lower and rising, with room to grow as waste systems improve.
The forward bet: zinc as a battery
Zinc’s newest role loops back to its oldest: it powered the very first battery in 1799 and still dominates the disposable batteries in a drawer. Now rechargeable zinc chemistries (zinc-ion, nickel-zinc, zinc-air, zinc-halide) are being built for grid-scale storage, where their pitch is not energy density but safety and duration. (Zinc Battery Initiative, 2025.)
The contrast with the lithium-ion battery is the point: zinc grid batteries are non-flammable, with no thermal runaway, able to hold charge for many hours to power a home or a microgrid, and made from an abundant, widely traded metal, trading energy density for safety and duration. If long-duration storage becomes the missing piece of a renewable grid, zinc’s tension resolves neatly: the metal that protects the steel holding up wind turbines could also help store what they generate.