Assembly Line

How mercury is made

Roast a soft red rock in moving air, chill what comes off, and a metal that stays liquid at room temperature runs out.

stations
5
things upstream
2
raw sources
2
step from the ground
1

The short version

Even the richest ore holds only 2.5% of this metal, locked up as the red sulfide cinnabar. Plants heat crushed ore in moving air, so oxygen takes the sulfur and the freed metal rises as vapor. A cooled column turns that vapor into liquid, distillation cleans it, and it ships in iron flasks.

  1. Crush the red ore

    Ore from the mine is broken small so heat and air can reach the cinnabar inside it. Cinnabar is soft, with a Mohs hardness of 2 to 2.5, and grinds readily.

    Goes in
    Cinnabar

  2. Roast in a rotary furnace

    The crushed ore tumbles through a rotary furnace in a current of air. Oxygen binds to the sulfur and leaves as sulfur dioxide gas, and the metal evaporates. Spent rock comes out as calcines, and runoff from abandoned calcine piles is a recognized source of ecological damage.

    Goes in
    Air

  3. Condense the vapor

    Hot furnace gas climbs into a condensing column, where the metal cools from vapor back to liquid. Refining this metal is hazardous work and a historic cause of poisoning.

  4. Distill out impurities

    The collected liquid is heated again and purified by distillation. Different substances boil at different temperatures, so the metal comes off apart from whatever it dragged along.

  5. Fill iron flasks

    Finished metal is most often shipped in iron flasks. It forms amalgams with almost every common metal, and iron is the exception. Prices are quoted by the flask.

    76 pounds to a flask

End of the lineMercury Next it goes into neon sign.

Worth repeating

  • Mercury became the first known superconductor in 1911, when it was chilled below 4 K.
  • The mines at Almadén in Spain have produced about 250,000 metric tons of mercury over the past 2000 years.
  • Nevada's McDermitt Mine, the last mercury mine in the United States, closed in 1992.

Back to the ground

Follow every input upstream and mercury starts as these 2 raw sources.

CinnabarAir

See it on the map

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Where it comes from

  1. China88% of world output, 2200 tonnes
  2. Tajikistan178 tonnes
  3. Russia50 tonnes
  4. Mexico32 tonnes

Mine output in 2020, out of about 2500 tonnes worldwide, as given on Wikipedia.

Where it goes next

Mercury feeds 1 line directly.

Neon sign

Keep walking

Non-alcoholic beer 6 stations · 21 raw sources Cotton candy 9 stations · 17 raw sources Foundation makeup 6 stations · 24 raw sources Toothpaste 7 stations · 20 raw sources Hairspray 7 stations · 21 raw sources Basketball 8 stations · 20 raw sources

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Sources

Cite this page: "How mercury is made." Assembly Line, 2026-11-03. https://assemblyline.org/make/mercury

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