Industrial Explosives 12
Industrial Explosives 12
Industrial Explosives 12
the history of chemical explosives lies in the history of gunpowder. During the Tang
Dynasty in the 9th century, Taoist Chinese alchemists were eagerly trying to find the elixir of
immortality. In the process, they stumbled upon the explosive invention of gunpowder made
from coal, saltpeter, and sulfur in 1044.
Gunpowder was the first form of chemical explosives and by 1161, the Chinese were
using explosives for the first time in warfare. The Chinese would incorporate explosives fired
from bamboo or bronze tubes known as bamboo fire crackers. The Chinese also used inserted
rats from inside the bamboo fire crackers to fire toward the enemy, creating great
psychological ramifications—scaring enemy soldiers away and causing cavalry units to go
wild.
Though early thermal weapons, such as Greek fire, have existed since ancient times, the
first widely used explosive in warfare and mining was black powder, invented in 9th century
in China by Song Chinese alchemists. This material was sensitive to water, and it produced
copious amounts of dark smoke. The first useful explosive stronger than black powder was
nitroglycerin, developed in 1847.
What is Industrial Explosives
What is an explosive?
Explosive is a solid or liquid substance or a mixture of substances which on
application of suitable stimulus is converted in a very short time interval into other more
stable substances, largely or entirely gaseous with the development of heat and high
pressure
Explosive materials may be categorized by the speed at which they expand. Materials that
detonate (the front of the chemical reaction moves faster through the material than the
speed of sound) are said to be "high explosives" and materials that deflagrate are said to be
"low explosives". Explosives may also be categorized by their sensitivity. Sensitive
materials that can be initiated by a relatively small amount of heat or pressure are primary
explosives and materials that are relatively insensitive are secondary or tertiary explosives.
A wide variety of chemicals can explode; a smaller number are manufactured specifically
for the purpose of being used as explosives. The remainder are too dangerous, sensitive,
toxic, expensive, unstable, or prone to decomposition or degradation over short time
spans.
Explosion
is a violent bursting or expansion caused by the release of mechanical, chemical or
nuclear energy from a confined area. This is a phenomenon resulting from a sudden release
of energy and this happens so rapidly that a local accumulation of energy occurs at the site
of explosion moving outward in various ways.
Implosion is a Similar phenomenon except that the energy released is initially directed
inward
Types of Explosion
a. Mechanical Explosion –it is a sudden breaking apart, shattering. or bursting into pieces
by internal pressure, such as those caused by expansion of gas producing high pressure
beyond the capacity of the container. Also known as pressure explosion.
c. Chemical explosion -a source of explosion wherein the source of energy comes from an
explosive substance such as gunpowder produced through the extremely rapid
transformation of the unstable substances accompanied by the formation of heat.
Some examples of explosives
1. Dynamites – first explosive invented by Alfred Nobel. It contains up to 75%
Nitroglycerin absorbed and desensitized by 25% diatomaceous earth(kieselguhr)/Oxidizer
can be relapsed to increase the energy yield.
2. Ammonium nitrate explosives – (AN-nitro mixture and AN-fuel oil or ANFO) is the
most commonly used industrial explosive, which comprises 96% ammonium nitrate and
6% fuel oil.
is the ammonium salt of nitric acid. is a common agricultural fertilizer - and a
deadly explosive agent. The explosive force occurs when solid ammonium
nitrate decomposes very rapidly into two gases, nitrous oxide and water vapor
3. Water explosives – slurries and water gel, explosive emulsions
Slurries and water gels – made of aqueous solution of ammonium nitrate and
sodium or calcium nitrate, gelled by guar gum or cross linking agents.
Explosives Emulsions – sensitized by air bubbles, introduced by means of hollow
glass or plastic bubbles. The storage time is limited because of the bubbles.
1. Blasting caps – one of the most commonly found explosives used to setoff
main charge. These are small tin cylinder with silver and copper color with
0.25 to 0.5 inch diameter and 2 to 6 inches in length. It contains powerful and
sensitive explosives. Even the heat of a person hand can set off a blasting cap.
3. Detonating cord – usually, this has a white exterior containing PETN. This is
used to set off multiple charges simultaneously.
4. Blasting agents – a combination of fuel and oxidants such a fuel oil and
ammonium nitrate. The color ranges from brown to bright pink due to the fuel
added. This requires booster since the components are not confined and
cannot be set off by blasting cap. This kind of explosive was used in New
York World Trade Center and Oklahoma City bombing.
a. Method of initiation
b. Nature of explosive
c. Size and confinement of the charge (smaller container tends to increase the temperature
from the growing heat of reaction .
d. Physical condition(such as air density and temperature).
Explosive strength
The magnitude of an explosion can be established based-on the amount of energy that is
released. The absolute measure of explosion size is determined in terms of the energy
released by exploding an explosive.
Damage Mechanism
a. Brisance - is the direct measure of energy transmission from explosion to the target. This
'is the most severe because of its shattering action. Brisance is directly proportional to the
speed of decomposition of explosives. Explosives with high shattering power are termed
high explosives. The brisance effect of deflagrating materials is relatively small.
b. Sensitivity - is the effort required to initiate explosive decomposition. The lesser the effort
required, the more sensitive is the explosive.
a. Do not use two-way radios, radar, or television transmitting device within 500 feet.
This includes Mobile Data Terminals and cellular phones. Electromagnetic radiation
(EMR) given off by these devices can detonate the item.
b. Notify proper authorities. (BFP, Police department, EOD, etc.)
c. clear and control the area. The size and type of explosive, terrain, s shielding and
other factors will determine the area to be controlled.
d. Stage emergency medical service (EMS), Fire and Police units outside the control
point.
e. Do not proceed to the suspected explosive. It may have motion sensitive or acoustic
fuses that function when disturbed or senses target. use binoculars to observe the area.
f. reduce potential effect of blast and flying shrapnel by opening doors and windows
and by placing emergency vehicles in the path of the blast wave to act as shield.