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    млллллллн    лллллллл  ллллллллн               оолллллллллп
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  млпллллллмллллмолллллллл ол пллллл           м   лнллллл             м
 мл оллллллллллп  ллллллллл плм  плллмм    ммлллп ол олллн         ммлл
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          ARRoGANT                CoURiERS      WiTH     ESSaYS

Grade Level:       Type of Work           Subject/Topic is on:
 [ ]6-8                 [ ]Class Notes    [Technical Explanation   ]
 [ ]9-10                [ ]Cliff Notes    [of different types of   ]
 [ ]11-12               [x]Essay/Report   [explosives              ]
 [x]College             [ ]Misc           [                        ]

 Dizzed: 09/94  # of Words:1607  School: ?              State: ?
ФФФФФФФФФ>ФФФФФФФФФ>ФФФФФФФФФ>Chop Here>ФФФФФФФФФ>ФФФФФФФФФ>ФФФФФФФФФ>ФФФФФФФФФ

SCICAN INVESTIGATION REPORT


Purpose:
    To learn about the different areas of explosives and the separate
explosives related to each group.

Explosive adj. 1. of, involving, or characterized by an explosion
or explosions.
2. capable of exploding or tending to explode.
3. potentially violent or hazardous; dangerous: an explosive situation.
4. Phonetics. another word for plosive.
5. a substance that decomposes rapidly under certain conditions with the
production of gases, which expand by the heat of the reaction.  The energy
released is used in firearms, blasting, and rocket propulsion.

    The context of explosive that I am dealing with in my investigation is
the fifth context mentioned above.  I chose to do explosives because I am
very interested in them and their abilities.


Basic Description of Explosives

    Explosives are substances that produces a rapid, violent reaction when
exposed to heat, a strong blow or a special detonator.  During the
reaction, explosives give off large amounts of gases at high pressure.  The
powerful blast of energy released during an explosion gives explosives many
commercial and military uses.   Explosives let construction workers clear
land away for building roads or buildings with little effort.  They are
used in digging mines and to loosen the flow of oil deep beneath rock in
oil wells.  They blow away tunnels through mountains and send rockets into
space.  In war, explosives are used to damage cities, destroy ships and
airplanes, and kill enemy troops.  As you see, explosives aren't always
used as harmless substances.

    Explosives may be solids, liquids, or gases.  However, all explosives
consist of a fuel and an oxidizer--a substance that supplies the oxygen
needed to make the fuel burn.  When the most powerful explosives detonate,
a chemical reaction takes place very quickly (usually in less than a
millionth of a second).  Liquids and solids change to hot gases that expand
with a large blast of heat and pressure.  The higher the pressure, the more
powerful the explosion is.

    There are four main types of chemical explosives--primary explosives,
high explosives, blasting agents, and low explosives.

    Primary Explosives should be handled in small quantities.  They are
very sensitive to heat, and even a spark of static electricity can cause
them to explode.  A few primary explosives include lead azide, lead
styphnate, and mercury fulminate.  They are usually used in detonators to
set off other explosives.

    High Explosives detonate with greater power than primary explosives but
are less sensitive.  They usually require a detonator to set them off.
Common types of high explosives include nitroglycerin; RDX; TNT; PETN; and
pentolite, a combination of TNT and PETN.  Most high explosives are used
commercially for blasting and excavating, but they also are used by the
military in grenades, bombs, and artillery shells.  High explosives can be
mixed with substances called plasticizers to produce plastic explosives.
Plasticizers, like such as oil and wax, make it easy to shape explosives
into various forms.  Plastic explosives have been used mostly by terrorists
because of the ease of concealment but it has been used in bombs and by the
armed forces in land mines.

    Blasting Agents are the safest and least expensive explosives used in
industry.  They are usually used to blast away rock in excavating and
mining operations.  Common blasting agents include dynamite and mixtures of
ammonium nitrate and fuel oil.

    Low Explosives burn rapidly rather than detonate.  The most common type
of low explosive is gunpowder.  It serves as a propellant to shoot
ammunition from guns and other weapons.  Fireworks are also low explosives.

    Below, I will talk about high explosives, low explosives, and blasting
agents.  I will talk about the explosives in each group separately.



High Explosives

Nitroglycerin

    Nitroglycerin, also called Nitroglycerol, is a powerful explosive.  It
is the principal explosive ingredient of dynamite.  Pure nitroglycerin is a
heavy liquid that is clear and has the consistency of motor oil.  The
commercial product is usually a yellowish or brownish colour.  When
nitroglycerin explodes, it expands to form gases that take up more than
1,000 times as much space as the liquid.  That would mean that if you had
10 ml of nitroglycerin, the gases created from the explosion would be close
to 10,000 ml.  The explosion of nitroglycerin is about three times as
powerful as that of an equal amount of gunpowder, and the explosion speed
is 25 times as fast as that of gunpowder.  Although its explosive
capabilities are very great, it is not often used as an explosive.  Doctors
use nitroglycerin to treat certain heart and blood-circulation diseases.

RDX (Cyclonite or Hexogen)ФФ

    RDX is a powerful explosive also known as cyclonite and hexogen.  It is
commonly used as a war explosive, being the main explosive charge in bombs.
It has wide use in detonators and fuses.  RDX is made by the action of
nitric acid on hexamethylene-tetramine, a product of formaldehyde and
ammonia.  When RDX is mixed with liquid TNT, an explosive called
Composition B is formed.  This explosive is more powerful than TNT, and has
replaced it in most artillery shells.

TNT (Trinitrotoluene)

    TNT is short for trinitrotoluene, a powerful solid explosive.  TNT is
made up of the elements nitrogen, hydrogen, carbon, and oxygen.  The
explosive is made by nitrating the chemical compound toluene.  The
explosive made forms in pale yellow crystals that may darken to a darker
brown colour. These crystals of TNT can be handled safely.  TNT can be
melted at low heat without igniting, and so can be molded to increase its
usefulness.  TNT is used alone and in mixtures with other explosives, such
as PETN, RDX, and ammonium nitrate.  It is mainly used as the explosive
charge for shells and bombs.

PETN (Pentaerythritol Tetranitrate)ФФ

    PETN is short for pentaerythritol tetranitrate, an explosive more
powerful than TNT.  It is used as the core of detonating caps and fuses
because it is capable of exploding in small devices.  The combination of
PETN and TNT is called pentolite.  Doctors also use PETN like they do
nitroglycerin, in treating some heart disorders.



Low Explosives

Gunpowder

    Gunpowder is an explosive material that burns rapidly to form
high-pressure gas.  Expansion of this gas inside the barrel of a gun can
accelerate a bullet to great speed.  Gunpowder is therefore used as a
propellant in a variety of ammunition.  It is also used in explosives for
blasting operations, in fireworks, and in fuses.

    There are several kinds of gunpowder.  The first important substance
used as gunpowder in guns and cannons was black powder.  Black powder
consists of a mixture of saltpeter (potassium nitrate), charcoal, and
sulfur.  These ingredients can be mixed together in the right proportions
and be used as a powder.  Sometimes, graphite is added.  The texture of
black powder can range from fine powder to larger pellets.

    The basic formula for black powder has been modified for special
purposes. Sulfurless gunpowder contains saltpeter and charcoal but no
sulfur.  It is not as powerful as regular black powder, but it corrodes the
gun barrel less.  Another variation is the black powder used in fireworks
and blasting agents.  The saltpeter is sometimes replaced by less expensive
sodium nitrate.

Cordite

    Cordite was one of the original smokeless powders used to propel
projectiles from guns.  It replaced gunpowder in many cases because it
burned with a lot less smoke.  However, cordite damaged gun barrels much
more than gunpowder did.  The name cordite refers to the cordlike lengths
in which it was made.  Cordite is composed of 30 percent nitroglycerin, 65
percent nitrocellulose, and 5 percent petrolatum.



Blasting Agents

Dynamite

    Dynamite is one of the most important industrial explosives.  It is
used to blast out damsites, canal beds, mines, quarries, and the
foundations for large buildings.  It also has been used for demolition in
warfare.

    The main explosive in dynamite is nitroglycerin.  It is mixed with
other materials--some explosive and some nonexplosive--and packed in
cylinders made of waxed paper or plastics.  These cylinders, called
cartridges, range from 7/8 to 8 inches (22 to 200 mm) in diameter and from
4 to 30 inches (10 to 76 cm) in length.

    To use dynamite, workers insert an explosive device called a detonating
cap or blasting cap into one end of the cartridge.  They place the
cartridge in a hole bored into the material to be blasted.  Earth is packed
around and behind the cartridge.  After moving to safety, the workers set
off the detonating cap--and the explosion--by means of a fuse or an
electric current.

    There are four main types of dynamite.  They are:  straight dynamite,
ammonia dynamite, straight gelatin, and ammonia gelatin.

   Straight dynamite contains nitroglycerin and an absorbent, chemically
reactive mixture, such as wood pulp and sodium nitrate.  It is the oldest
type and has been replaced by ammonia dynamite for most uses.

    Ammonia dynamite is more powerful, safer, and less expensive than
straight dynamite.  It contains ammonium nitrate and produces fewer toxic
fumes and cooler gases than other dynamites do.  It is called a permissible
explosive, which means that it can be used safely in mines where extreme
heat could ignite dust or gas in the air.

    Straight gelatin is made from a stiff gel called blasting gelatin.
Blasting gelatin consists of nitroglycerin mixed with a small amount of
nitrocellulose.  Sodium nitrate and other ingredients are added to make
straight gelatin.  Straight gelatin has been replaced by ammonia gelatin
for most uses.  Ammonia gelatin is made by adding ammonium nitrate and
other ingredients to blasting gelatin.  Ammonia gelatin is waterproof.  It
is used for underwater blasting.

Conclusion: I have learned many new things that I did not know about
explosives before I did my investigation.  I learned that there are four
main groups of explosives, and each group has different uses.
