How graphite is mined
Graphite is so soft it smears onto the waste rock around it and drags that rock along during cleaning.
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The short version
Graphite forms when carbon-rich sedimentary rock or coal is cooked deep underground. Miners reach it by open pit or tunnel, then crush the ore and float the graphite off in tanks of froth. Because graphite coats the waste rock, the crushing and floating may repeat up to seven times, or acid may dissolve what is left.
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Dig out the ore
Deposits are worked by both open pits and underground tunnels. Flake graphite comes from metamorphic rock, lump graphite from veins, and amorphous graphite from coal that was baked by heat underground.
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Crush the rock
Ore is broken down to free the graphite from the surrounding rock. Crews handle coarse flakes carefully at this point, since large flakes are worth more than fine powder.
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Float it on froth
In flotation tanks, light graphite rises with the froth and the waste rock sinks. Graphite's softness makes this harder than it sounds. It smears over waste particles and carries them up too, so the concentrate is reground and floated again, up to seven times.
up to 7 rounds
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Sort by flake size
The finished concentrate is screened into size fractions and tested for carbon content. Blends are then made to order, because a crucible maker and a brake-lining maker want different flakes.
Worth repeating
- Modern froth flotation, a process now used across mining, traces its beginnings to graphite and an 1877 German patent.
- Graphite is carbon, the same element as diamond, with its atoms arranged in sheets that slide past one another.
Where it goes next
Natural graphite feeds 1 line directly.
Keep walking
Sources
Cite this page: "How graphite is mined." Assembly Line, 2026-11-03. https://assemblyline.org/make/natural-graphite