How zinc ore is mined

Zinc's main ore was named for the Greek word for deceiving, because it looks like galena but yields no lead.

stations: 4
things downstream: 150

The short version

Zinc ore comes up from open pits or underground workings, mostly as a dark sulfide called sphalerite. Mills crush it, mix it with water and grind it to a slurry, then blow air through flotation cells so the zinc sulfide climbs onto bubbles and leaves as froth. The same mineral also yields small amounts of cadmium, gallium, germanium and indium.

Cut out the sulfide

Zinc ores are taken from open pits and from underground, where cut-and-fill stoping is the most common method. Mount Isa in Australia reaches its ore through a shaft 1,144 m deep and hoists it in skips.
Grind to a slurry

Rock is crushed, mixed with water and milled until sulfide grains come free. Mount Isa's concentrator was built around rod and ball mills, and it added heavy-medium separation to reject waste ahead of them.
Float the sulfide grains

Reagents and air go into flotation cells. Zinc sulfide clings to the bubbles and is skimmed off as froth while waste rock sinks. Sphalerite often travels with lead minerals, so a mixed ore like Mount Isa's gets a lead-silver float and a separate zinc float.
Regrind and clean

Some ore needs another pass. To handle its George Fisher ore, Mount Isa added ISAmills for ultra-fine regrinding, along with better cleaner flotation, to lift recovery and concentrate grade. The finished concentrate goes to a smelter for roasting.

End of the lineZinc ore Next it goes into zinc, silver, gallium and 2 more.

Worth repeating

Sphalerite got its name in 1847 from the Greek word for deceiving, because it is so hard to identify.
Miners called the ore blende, from German words for blind or deceiving, since it looks like galena yet holds no lead.
Alongside zinc, sphalerite also yields cadmium, gallium, germanium and indium.