Humans have been using mercury since ancient times. In the Middle Ages, mercury was used in alchemy and medicine. Only in modern times did it become clear that mercury is highly poisonous.
Safely disposing of mercury
The paradox of energy-saving bulbs
There's also mercury in fluorescent lighting. Although they save energy, disposal can be a problem. Energy-saving bulbs should not be thrown away with regular waste, due to the tiny amount of mercury they contain.
Safely disposing of mercury
From the shredder ...
A fork-lift operator at the DELA recycling company in Essen, Germany, dumps a load of compact fluorescent tubes into a shredder. In order to prevent mercury from escaping, a filtering ventilation system sucks the air away.
Safely disposing of mercury
... to the silo ...
The shredded compact fluorescent tubes are stored in a silo until a spiral conveyor carefully carries them to a glass-washing area.
Safely disposing of mercury
... and in the washing machine.
Workers wash masses of broken glass from the shredded lamps to recover luminescent material and mercury from the glass shards.
Safely disposing of mercury
Pure glass
Glass from light bulbs is considered valuable in industrial processes, since it can withstand high temperatures and varying levels of pressure. But producers need the purest possible material.
Safely disposing of mercury
Vacuum drying
The glass-washing process leaves behind sludge with high mercury content. Mercury is distilled from this, like in a liquor distillery.
Safely disposing of mercury
Valuable illuminant
The pure illuminant is returned to the light bulb producers. They gladly pay for it, because it contains the rare earth elements yttrium and europium.
Safely disposing of mercury
Distillate
Pure mercury also comes out of the vacuum dryer. Since mercury is quite dense, it weighs 1.7 times as much as the same volume of iron. The amount shown in the jar here comes from 500,000 compact fluorescent light bulbs.
Safely disposing of mercury
Detox
Sulfur is directed to the left part of this machine, and from above, liquid mercury. The combination produces mercury sulfide, which has a very stable composition and is no longer poisonous.
Safely disposing of mercury
Red mercuric sulfide
The mercury sulfide can be disposed of by storing it in old mines. This, along with rock filling, stabilizes the old mining shafts.
Safely disposing of mercury
Disposal - as art
This piece of modern art, made from mercury sulfide, hangs on the wall at the DELA recycling company in Dorsten, Germany.
Author: Fabian Schmidt / sad
| Editor: Andreas Sten-Ziemons
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