How copper ore is mined
Modern copper ore is under 1% copper, so most of every truckload is thrown away.
- stations
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- things downstream
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The short version
Copper comes mainly from huge open pits in rock that holds only a sliver of metal. The rock is crushed to a fine powder, mixed with water and chemicals, and bubbled with air so the copper sulfide particles stick to the bubbles and float off as a froth. The froth is dried into a concentrate for smelting.
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Open the porphyry pit
Most copper is dug from big open pits in so-called porphyry deposits, which hold from 0.4 to 1.0% copper. Ore averaging less than 0.6% is normal in this century, so the pit moves enormous tonnages of rock for a small amount of metal.
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Mill to powder
Crushers and rotating mills reduce the rock until it is made of separate mineral particles, each smaller than 100 micrometers. Only at that size can the copper minerals be pried free of the surrounding silicate rock.
particles under 100 micrometers
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Float the sulfides
In tanks of water, reagents coat the copper sulfide grains so they repel water. Air is pumped through, the grains cling to the bubbles, and the copper-rich froth is skimmed from the top. Lime is used to raise the pH of the bath so the reagents work better.
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Leach the oxide ores
Oxidized ores do not float well. Instead they are piled in heaps and soaked in dilute sulfuric acid, which dissolves the copper into a solution that is collected at the bottom of the pile.
Worth repeating
- Global copper production was estimated at 22.8 to 22.9 million metric tons in 2024, from ore that averages under 0.6% copper.
- The rock left behind after flotation can be reprocessed for other metals, including lead from galena and zinc from sphalerite.
Where it comes from
- Chileat least one-third of the world total
- United Statessecond
- Indonesiathird
- Perufourth
Ranking by mined copper in 2005, from the British Geological Survey as quoted on Wikipedia; the source gives no newer ranking.
Where it goes next
Copper ore feeds 3 lines directly and reaches 118 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How copper ore is mined." Assembly Line, 2026-11-03. https://assemblyline.org/make/copper-ore