ch e m i c a l s used i n m i n i n g 485
Chemicals Used in Mining
Chemicals used in mining and processing minerals contaminate the land,
water, and air, causing health problems for workers and people living near
mines. Toxic chemicals used in mining include:
• cyanide, sulfuric acid, and solvents for separating minerals from ore
• nitric acid
• ammonium nitrate and fuel oil (“ANFO”) used in blasting tunnels
• heavy metals such as mercury, uranium, and lead
• gasoline, diesel fuel, and exhaust fumes from vehicles and equipment
• acetylene for welding and soldering
Cyanide
Cyanide is used to separate gold from ore.
In its pure form, cyanide has no color and
smells like bitter almonds. It may lose this
smell when it combines with other chemicals.
It can be used in powder, liquid, or gas forms.
Cyanide is deadly when swallowed.
An amount the size of a grain of rice is
enough to kill a person. Exposure to low
doses over a long time may cause a swelling in the throat (goiter), which
can also be caused by malnutrition.
Cyanide is often spilled into waterways during gold mining, and when
ponds filled with mine wastes burst and spill. Mining companies say that
cyanide in water quickly becomes harmless. But this is true only when there
is lots of sunlight and oxygen. Even then it leaves behind other harmful
chemicals. If cyanide is spilled underground, or if the weather is cloudy or
rainy, it can remain harmful for a long time, killing fish and plants along
rivers and making water unsafe for drinking and bathing. Cyanide is so
dangerous that it has been banned in some countries.
Sulfuric acid
Sulfuric acid is a toxic chemical used in copper mining. It is also a byproduct
of many kinds of mining, mixing with water and heavy metals to form acid
mine drainage. Sulfuric acid smells like rotten eggs. Contact with sulfuric acid
can cause burns, blindness, and death.
A Community Guide to Environmental Health 2012