Diatomite is a sedimentary rock, that is white and yellowish in
color. It is composed of fossilized skeletons of one-celled algae-like
plants called diatoms. It is accumulated in marine areas. The
Honeycomb sillia structure is useful because of its high absorptive
capacity and surface area. It is also very chemically stable. Its
principal use is filtration.
This substance of diatomite is extracted from many countries
around the world. Out of 30 world countries the largest suppliers are
the United States, China, Denmark, and Japan. China supplies about
350 thousand metric tons, Denmark extracts 375 thousand metric
tons, and Japan, 190 thousand metric tons. About 725 thousand
metric tons of diatomite are extracted from the US Worldwide about
2,150 thousand metric tons are removed from the earth.
This product consists of approximately 90 percent silica, and the
remainder consists of compounds such as aluminum and iron oxides.
The material is extracted by a dredging barge cuts sediment with
rotating knives, mixes it with water and pumps it along a suspended
pipeline to the shore. Because diatomite is made from a skeletal
structure of diatoms, it isn’t made of chemicals that need to be
extracted. It is highly unreactive to other chemicals. It also has a
low thermal conductivity rate and a high fusion point.
Most diatomite mines are open pit mines because the deposits
are usually at or near the surface. Open pit mines are especially hard
on the environment because they are very large holes in the ground.
Diatomite is also mined when geologic uplifting brings these deposits
above sea level. The diatomite is easily mined this way, however,
being in marine areas, pollution in the water is a big concern.
Through the use of many mining machines, the waters can be easily
polluted. The method of dredging to cut away at the sediment does
not seem like it would be as environmentally friendly as well. Aside
from the mining having impact on the actual land, diatomite mining
has impacts on birds in surrounding areas. Many birds show a
tendency to avoid dredging areas. Besides factors of noise and
pollution and general unpleasantness of machines, birds also rely on
animals in shallow water for food where dredging has occurred.
Currently there are no recycling methods for diatomite. The
eventual replacement of diatomite filters with membrane types may
be speeded by legislation regarding waste disposal, which would make
the option of dumping diatomite cake in landfill sites more expensive
or even prohibited. One environmental specification of color is put on
diatomite, because it is a calcine product. It has to be of a light
whitish color or it is not available to be mined. This helps
environmentally because the color determines a standard for what
companies can and cannot mine.
I think one way for lessening the impact on the environment,
would be to work harder at developing recycling methods for
diatomite cake. If recycling could be put into use not as much
diatomite would need to be mined. To excavate diatomite, different
combinations of rippers, dozers, scrapers, front-end loaders, power
shovels, and dump trucks are used. Underground mining is not too
uncommon outside the United States. Usually, room-and-pillar
methods are used, often with equipment similar to that used in open
pits; in the smallest mines, hand tools are used. Dredging is used to
recover diatomaceous mud from the bottom of lakes. Since all these
methods are used in excavation, I think the best idea would be to
choose the method with the least impact environmentally.
Sixty four percent of the diatomite mined is used in filtration.
Fourteen percent is used for absorbents, and twelve percent used in
fillers. While two percent used for insulation, and eight percent used
in other ways. Diatomite is principally used in filtration of various
alcoholic beverages, sugar, oil, organic and inorganic chemicals, and
Many materials can be substituted for diatomite. Expanded
perlite and silica sand compete for filtration purposes. Other filtration
technologies use ceramic, polymeric, or carbon membrane. Alternate
filler materials include talc, ground silica sand, ground mica, clay,
perlite, vermiculite, and ground limestone. For thermal insulation
materials such as various clays and special brick, mineral wool,
expanded perlite, and exfoliated vermiculite can be used.
Conservation would mostly be attained through finding ways to
recycle or more efficiently using the cake, or using substitutes for the
Diatomite is an excellent filtering material for many things.
Most commonly used in beverages, fruit juices, soft drinks, beer, and
wine. It is used in chemicals like sodium hydroxide, sulfuric acid, and
gold salts. Filtration of cooking oils, vegetable and animal, and
sugars, cane, beet, and corn,