Explosives- Chemical Education

Explosives

Explosives, highly exothermic chemical reactions that produce expanding gases were first made by Asian alchemists more than one thousand years ago when they discovered mixtures of saltpeter (KNO3) and sulfur could be detonated. Explosives are classified as:
1. Primary (Initiators): Do not burn but detonate if ignited (mercury fulminate).
2. Low (Propellants): Burn at steady speed and detonated only under extreme conditions (gunpowder).
3. High: Release large amounts of energy when detonated (nitroglycerine).
 
  Roger Bacon (1220-1292)
Born England, Bacon studied geometry/arithmetic/music/astronomy in France. Upon returning to England in 1247, Bacon became interested in science. His experiments using lenses/mirrors resemble modern scientific approaches. In 1257 Bacon left the University of Oxford and entered the Order of Friars Minor. His interests in the sciences continued and in 1266 Bacon wrote to Pope Clement IV proposing a science encyclopedia. Pope Clement IV misunderstood what Bacon was proposing and assumed the encyclopedia already existed. So when the Pope asked to see the encyclopedia, Bacon rapidly began work on the project. The project was carried out in secret since Bacon's superiors opposed what he was doing. Bacon hoped to demonstrate that science had a rightful role in the university curriculum. But In 1268 Pope Clement IV died along with Bacon's chance to see the project accepted (only parts of the manuscript were ever published).

What is the connection between Bacon and explosives? While composing the encyclopedia, Bacon became aware of the discovery by the Asian alchemists. This prompted Bacon to experiment with mixtures of saltpeter, sulfur, and a new ingredient (charcoal); Bacon had made black powder (the early form of gunpowder).
One hundred years later friar Berthold Shwarts looked into this black powder. Schwarts took a long iron tube and closed one end except for a tiny hole. He filled the tube with black powder and stuffed a small pebble in it. He touched a flame to the tiny hole and the pebble shot through the air with great speed. Schwarts had invented the "gun."
 

Nitroglycerin/Nitrocellulose

Five hundred years after Berthold Schwarts invented the gun, Ascano Sobrero (Italian) mixed nitric acid and glycerin to obtain nitroglycerine--an explosive so unstable that it could be detonated by the touch of a feather. One mole of nitroglycerine (227g) releases 1427 kJ upon exploding. It's volume increases from a liquid of approximately 1/4 L to gases occupying approximately 650 L.

In 1845, Christian Schoenbein made nitrocellulose (guncotton) by dipping cotton in a mixture of nitric and sulfuric acids. However, the material obtained was too unstable to be used as an explosive. Major E. Schultze (1860) of the Prussian army produced a useful propellant. He nitrated small pieces of wood by placing them in nitric acid and impregnated the pieces with barium and potassium nitrates. The purpose of the latter was to provide oxygen to burn the incompletely nitrated wood. Schultze's powder was  highly successful in shotguns but was too fast for cannon or even most rifles. In 1884 a French chemist, Paul Vieille, made the first smokeless powder as it is now known. He partially dissolved nitrocellulose in a mixture of ether/alcohol, then he rolled it into sheets and cut into flakes. When the solvent evaporated, it left a hard, dense material. This product gave satisfactory results in all types of guns.
 
  Alfred Nobel (1833-1896)
Alfred Nobel mixed nitroglycerin and silica (SiO2) forming a paste that could be safely used as an explosive--he patented this material as dynamite (1867). Nobel also invented the blasting cap to provide a safe and dependable means for detonating. Nobel's original blasting cap consisted of 80% mercury fulminate [Hg(ONC)2] and 20% potassium chlorate. Blsting caps today are lead azide [Pb(N3)2] due to its greater stability when stored under hot conditions.
A French newspaper--thinking Alfred and not his brother had died in 1886--ran his obituary under the headline, "The merchant of death is dead."  Nobel, displeased that his inventions became an instrument of war, established the Nobel Prize in categories reflecting his interests (Chemistry, Physics, Medicine, Literature, Peace).
 

Ballistite
In 1887 Nobel introduced ballistite, 40% nitrocellulose/60% nitroglycerin blended together with diphenylamine. When cut into flakes, this made an excellent propellant and it continued in use for over 75 years. The British refused to recognize Nobel's patent and developed a number of similar products under the generic name cordite.
 
 
Cordite
Sir James Dewar (1842-1923) is best known for his work with low-temperature--he invented the thermos and produced both hydrogen and oxygen in liquid form. Along with Sir Frederick Abel, Dewar invented cordite (1889). This smokeless gunpowder consists of nitroglycerin, guncotton, and a petroleum substance gelatinized by addition of acetone.
 

Trinitrotoluene (TNT) 
Trinitrotoluene is a high explosive that is unaffected by ordinary shocks and therefore must be set off by a detonator. TNT is often mixed with other explosives such as ammonium nitrate to form amatol. Because it is insensitive to shock and must be exploded with a detonator, it  is the most favored explosive used in munitions and construction.
Why do nitro groups (NO2) lead to unstable compounds? Nitrogen has charge of +1 and nitro group have a strong tendency to withdraw (pull) electrons from other parts of the compound. Attaching three nitro groups to a compound leads to an extremely unstable situation.

 

Pentaerythritoltetranitrate (PETN)
PETN is a powerful high explosive with 140% the power of TNT. Because PETN  is more sensitive to shock or friction than TNT, it is primarily used in small caliber ammunition.

 

Cyclotrimethylenetrinitramine (RDX)
Also called RDX, Cyclotrimethylenetrinitramine is a white crystalline solid usually used in mixtures with other explosives, oils, or waxes. RDX has a high degree of stability in storage and is considered the most powerful high explosive. RDX is the main ingredient in plastic explosives.

 
 
ANFO (Ammonium Nitrate Fertilizer)
  Although ammonium nitrate (NH4NO3) is a benign fertilizer, when mixed with fuel oil it becomes a deadly bomb (ANFO). Dynamite or TNT are usually used to detonate ANFO (military manuals suggest using one pound of TNT for every fifty pounds of fertilizer). The deadly Oklahoma City Bomb was ANFO.
 

 
 

 
 du Pont de Nemours (1771-1834)
DuPont is one of the oldest continuously operating industrial enterprises in the world. The company was established in 1802 near Wilmington, Delaware, by a French immigrant, Eleuthére Irénée du Pont de Nemours, to produce black powder. The company was capitalized at $36,000 with 18 shares* at $2000 each. du Pont de Nemours had been a student of Antoine Lavoisier, the father of modern chemistry, and he brought to America some new ideas about the manufacture of consistently reliable gun and blasting powder. Due to increasing competition in the early 1900s, DuPont made the transition from an explosives manufacturer to a diversified chemical company.
_* The $2000 investment in 1802 is worth approximately $2.5 billion today.
 
Detecting Explosives
Today's challenge is not safe handling of explosives but early detection when used by terrorists. Here are 4 methods:
1. Canines:  ATF's explosives-detecting canine training program was established in 1992. Although not high tech, canines can detect minute quantities for a variety of explosives.
2. Chemical Sensor: Portable system the size of soccer ball is being developed by Sandia Laboratories that can detect/identify smallest traces of explosives. Known as chemical sensor system, molecules are collected on a fiber and "ion mobility spectrometer" identifies type of explosive.
3. Neutron Beam: Technology called Prompt Gamma Neutron Activation Analysis (PGNAA) directs beam of neutrons. When neutrons contact contaminant, they instantly produce high energy gamma rays. Explosives are identified from energy of gamma rays.
4. Lasers: Carbon dioxide laser scans/analyzes baggage surfaces. The interaction of laser radiation with traces of explosive causes micro burst.

 

History

The first chemical explosive was gunpowder, or black powder, a mixture of charcoal, sulfur, and potassium nitrate (or saltpeter). The Chinese invented it approximately 1,000 years ago. For hundreds of years, gunpowder was used mainly to create fireworks. Remarkably, the Chinese did not use gunpowder as a weapon of war until long after Europeans began using it to shoot stones and spear-like projectiles from tubes and, later, metal balls from cannon and guns.

Europeans probably learned about gunpowder from travelers from the Middle East. Clearly by the beginning in the thirteenth century gunpowder was used more often to make war than to make fireworks in the West. The English and the Germans manufactured gunpowder in the early 1300s. It remained the only explosive for 300 hundred years, until 1628, when another explosive called fulminating gold was discovered.

Gunpowder changed the lives of both civilians and soldiers in every Western country that experienced its use. (Eastern nations like China and Japan rejected the widespread use of gunpowder in warfare until the nineteenth century.) Armies and navies who learned to use it first—the rebellious Czech Taborites fighting the Germans in 1420 and the English Navy fighting the Spanish in 1587, for example—scored influential early victories. These victories quickly forced their opponents to learn to use gunpowder as effectively. This changed the way wars were fought, and won, and so changed the relationship between peoples and their rulers. Royalty could no longer hide behind stone walls in castles. Gunpowder blasted the walls away and helped, in part, to end the loyalty and servitude of peasants to local lords and masters. Countries with national armies became more important than local rulers as war became more deadly, due in large part to the use of gunpowder. It was not until the seventeenth century that Europeans began using explosives in peacetime to loosen rocks in mines and clear fields of boulders and trees.

Other chemical explosives have been discovered since the invention of gunpowder and fulminating gold. The most common of these are chemical compounds that contain nitrogen such as azides, nitrates, and other nitrocompounds.

In 1846 Italian chemist Ascanio Sobrero (1812-1888) invented the first modern explosive, nitroglycerin, by treating glycerin with nitric and sulfuric acids. Sobrero's discovery was, unfortunately for many early users, too unstable to be used safely. Nitroglycerin readily explodes if bumped or shocked. This inspired Swedish inventor Alfred Nobel (1833-1896) in 1862 to seek a safe way to package nitroglycerin. In the mid-1860s, he succeeded in mixing it with an inert absorbent material. His invention was called dynamite.

Dynamite replaced gunpowder as the most

BLACK POWDER

Black Powder, also known as Gunpowder, is an explosive that has been around, literally, for centuries. The exact origins of the formula are lost in time, but it is known that the Chinese used Black Powder in weaponry at least 1,000 years ago. Technically, Black Powder burns by a process known as deflagration. This differs from detonation in that Black Powder produces subsonic shock waves, as opposed to the supersonic shock waves produced by explosives such as Dynamite, C-4 or TNT. This means that Black Powder is better suited as a propellant (such as in fireworks, bullets and cannons) than blasting (such as in construction or demolition).

Safety

Black Powder is dangerous! The powder burns at a very high temperature, and is easily ignited. (High grade powder doesn't even need a flame to ignite - it can be set off by percussion, such as the firing pin of a pistol.) Basically, what I am saying is that if you are not careful, you could land up with very severe burns, or worse. Some basic guidelines to follow:

1.     Always mix ingredients in small amounts. Do not try to make 10 Kg of black powder (or any explosive) in one batch. Mixing small amounts of powder limits the potential damage should an unexpected explosion occur.

2.     Keep your workplace tidy. Always carefully clean up spilled chemicals. Some materials can spontaneously combust when mixed (this is especially true of nitrates and chlorates). For the same reason, use separate instruments (plastic spoons, mixing cups, etc) for different chemicals. Label your instruments so that you know what materials they have been in contact with.

3.     Mix materials outdoors. Chemical explosives contain their own internal source of oxygen, and cannot be smothered. If you start a chemical fire indoors, it can be nearly impossible to extinguish.

4.     Be aware of static sparks. Do not use metal instruments to mix or grind materials. Do not store chemicals in metal containers. Use ceramics or plastics wherever possible. Store chemicals and mixtures in plastic containers or ZipLoc. bags.

5.     Wear safety goggles. Should the worst happen, skin can be grafted. Eyes cannot be replaced.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ingredients

Black Powder has traditionally consisted of three ingredients: Potassium Nitrate (KNO3, also known as Salt Peter), Sulfur and Charcoal. The Sulfur and Charcoal provide fuel for the reaction, while the Potassium Nitrate provides Oxygen. By themselves, Charcoal and Sulfur will burn, albeit very slowly. The addition of an oxidizer (such as KNO3) greatly speeds up the burn rate of the fuel, resulting in an explosive reaction.
The traditional ratio of the ingredients is 15:3:2 of KNO3, Charcoal and Sulfur by weight (not volume!). However, simply mixing the dry ingredients together will not give you black powder. At best, you will get a green powder that will do little more than produce vast quantities of smoke, and annoy your neighbors. In order to make high-grade powder, a little work is needed.

Preparing the Ingredients

The quality of the resulting powder depends on a number of factors. The most important of these is binding, which refers to how tightly the KNO3 is mixed in with the Charcoal/Sulfur mixture. This is why a loose binding, such as a dry mix, produces a very low-grade powder.
The quality of the powder is defined by its burn rate, usually expressed in cm3/s. A burn rate of about 14 cm3/s or higher is required to use the powder as a propellant. (Also, possession and manufacture of powder with a burn rate of 14 cm3/s or higher constitutes a weapons violation under US law, unless you are also in possession of an ATF license.)
I will present two methods of preparing black powder here. The first produces powder with a slightly lower burn rate, but is safer to prepare. The second can produce very high quality powder, but contains an element of danger. The methods presented here will get you a burn rate of 14 cm3/s or better, depending on how much patience you have, and the quality of your ingredients.
The Charcoal/Sulfur mixture must be ground as finely as possible. Simply whacking away at your barbeque charcoal with a hammer is not going to cut it. The charcoal must be ground into a very fine powder. Commercial manufacturers use large machines known as ball mills to crush the charcoal and sulfur. A ball mill is basically a large rotating drum filled with charcoal, sulfur and a crushing agent, such as lead balls or heavy stones. The mill is rotated at high speed for up to 48 hours or longer. The result is a very finely powdered charcoal/sulfur mixture. (Note: for reasons which should be very obvious, the Potassium Nitrate is not mixed in with the fuel during the milling stage, unless you want to be picking bits of your ball mill out of the walls of your factory.)
Ball Mills are very expensive, and it is unlikely that the average hobbyist will be able to afford one. There are alternatives, however. One is to simply buy the charcoal in a powdered form. There are several mail order companies that will provide powdered charcoal. (See the list of suppliers at the end of this article). The other alternative is to fashion a ball mill of your own, if you happen to be a handyman. Or, you could simply buy a cheap gem-polishing toy mill from your local Wal-Mart, and use kids marbles, or heavy decorative stones as a crushing agent. You will have to run the mill continuously for at least 72 hours with this method, however. Assuming that you have a powdered charcoal/sulfur mixture in the right quantities, how do you get the KNO3 to bind to the mixture? The solution is to employ a useful property of Potassium Nitrate - it is soluble in water. Charcoal and sulfur, on the other hand, are not soluble in water. They will, however, absorb KNO3 from water under suitable circumstances. The addition of cold alcohol to the mix will have the effect of suddenly leaching the water out of the mixture, leaving just the salt behind, hopefully tightly bound to the fuel.

 

 

 

 

 

 

 

Method 1 - Boiling

Requirements:
Skillet, stovetop (preferably outdoors!), plastic strirrer, 750 ml of Isopropyl Alcohol, household sieves, coffee filters.
The recipe for producing black powder using this method is as follows (adjust quantities as desired, but remember to stick to the ratio). Before you start, have a 750 ml bottle of rubbing alcohol chilled in a freezer for at least 24 hours. (You can purchase rubbing alcohol, also known as Isopropyl Alcohol, from most any drugstore or supermarket).

1.     Mix 30 grams of powdered charcoal with 20 grams of powdered sulfur, as described above.

2.     Using a deep skillet, bring about three or four cups of water to boil. Stir in 150 grams of KNO3. Keep stirring until the Potassium Nitrate is completely dissolved. Add water as necessary, but try not to over-water the mixture.

3.     Slowly sift in the charcoal/sulfur mixture. The mixture will tend to float on top of the water, so you will have to agitate the slush with a spoon or a whisk. Keep stirring until you get a wet, grayish sludge. This could take a while, so take your time and be careful. Don't let any of the mixture slop out of the skillet onto the hot stove-top, or you will most likely start a fire.

4.     Once the sludge is uniformly mixed, remove the skillet from the stove. Pour in the chilled alcohol, and stir. Keep pouring and stirring until the sludge is cool enough to touch.

5.     Pour the sludge into a coffee filter placed in a sieve over a plastic container. Allow the water/alcohol to drain out until the sludge is dry enough to leave an impression when you press into it.

6.     Using a fine sieve, press the sludge through the sieve onto a large piece of cardboard or blotting paper. This should produce fine granules of powder. Take your time, evenly spreading the granules onto the paper or cardboard.

7.     Allow the granules to dry in direct sunlight for at least 24 hours. When dry, pour the granules through a finer sieve to remove any fine powder from the granules. This fine powder (known as meal powder) is not useful for firecrackers or propellants, but can be used to make fuses or fountains.

You should now have real, honest-to-goodness Black Powder. Congrats.

 

Method 2 - Agitation

This method is very similar to that described above, but differs in the manner in which the ingredients are mixed. Because it uses electrical equipment, it is considerably more dangerous than the previous method, but can produce very high quality powder.
Requirements:
Electric kitchen blender, 750 ml of Isopropyl Alcohol, household sieve, coffee filters.

1.     Pour 3 or 4 cups of boiling water into the blender. Slowly add 150 grams of KNO3. Cover the blender, and agitate at medium speed for about ten minutes. (Note - it is advisable to use an extension cord to start the blender from a safe distance. Again, this should be done outdoors!)

2.     Slowly mix in 50 grams of charcoal/sulfur mixture. This should be done by turning off the blender, pouring in a small amount of the mixture, restarting the blender and mixing until the charcoal/sulfur is completely wet. Repeat until all the fuel has been added and thoroughly mixed. (Take your time - remember: haste kills!)

3.     Let the blender run at high speed for about 15 minutes. Slowly pour in the alcohol while the blender is running. You should hear the blender slow down as the mixture solidifies. Add more alcohol until the mixture is cool to the touch.

4.     Follow steps 5 through 7 from method 1.

 

 

 

 

 

 

 

Testing Your Powder

In order to test the burn rate of your powder, all you need is a stopwatch and a soda can. Thanks to the magic of the metric system, it turns out that 1 ml = 1 cm3. Soda cans are usually marked with the volume in ml (the average can is 340 ml). You may not want to use an entire can, however, as that would be a waste. Most supermarkets sell soda in halfsize cans (such as you usually get on airliners). Or, you could simply cut a full sized can using a pair of metal shears, and calculate the volume of the can. (For those of you who slept through math at high school, the formula is v = h*pi*r2. Remember to use metric units. In other words, measure the height and diameter of the can in centimeters, not inches, miles or furlongs, or whatever else you Yanks have got stuck with.)
Now, fill the can to the brim with powder. Do not cover the can! One word - shrapnel! Insert a fuse (you can usually buy so-called "safety fuses" from a supermarket around the 4th of July, or New Years. Also, fireworks retailers almost always carry lengths of safety fuse. If you are desperate, simply insert a match into the can, with the match-head just under the surface of the powder.) Light the fuse, wait for the powder to start burning, and time the burn with the stopwatch. Divide the volume of powder by the time it takes to burn completely, and you have your burn rate.

 

 

 

 

 

Things that go Bang!

So now you have black powder. What do you do with it? Short answer - you make it explode, of course! This is achieved by confining the powder inside a container and initiating a pressure-feedback loop. For the physics-impaired, this is how it works: the burn rate of black powder is directly proportional to the surrounding pressure. The more the pressure increases, the faster the powder burns. If the powder burns in a confined space, it will release large quantities of gas, which in turn increase the internal pressure, which increases the burn rate of the powder, which releases more gas. Well, you get the idea. The feedback loop continues until the internal pressure bursts the container, resulting in a large bang.

The whole process takes place in a matter of milliseconds, if your powder is of sufficient quality. This is why we use granulated powder for firecrackers - granules means more surface area. More surface area means that the hot gases traveling through the container can ignite more powder, more quickly.
So, what do we use for a container? All those of you who said "metal pipes" or "glass bottles", please pick up your things and get the hell out of my classroom. Anyone with two brain cells to rub together should realize that when a metal or glass container bursts, the air will suddenly be filled with very tiny pieces of glass or metal, traveling at speeds of several hundred meters per second in all directions. This, boy and girls, is what we call shrapnel, and our aim is to avoid it, unless you want to end up looking like a piece of Swiss cheese.
Firecracker containers are made of cardboard, or soft plastic. Not only is a piece of flying cardboard far less dangerous than a supersonic piece of sharp metal, but cardboard and plastic containers tend to be consumed by the heat of the explosion, leaving even fewer potentially dangerous missiles to fly around.
The suppliers listed below will carry pre-made cardboard tubes, with plugs that are glued into the ends to form a tightly contained tube. If you happen to be impatient, you can probably find something around your house that might do the trick.
Two fairly common household items that you could use are the soft plastic containers that 35 mm film is usually sold in, or the soft plastic containers in which your local pharmacist usually dispenses drugs. (By the way - if your local pharmacist is a guy named "Jim" who hangs around dark alleys, you shouldn't be experimenting with explosives. Kapish?)
To start with, make a small hole in the top of the container. Punch or drill a hole about 2 to 3 mm in diameter in the top of the container. Place a wooden toothpick in the whole (you'll find out why later.) Fill the container about one-third to one-half with granulated black powder, and glue the top back on. Use a strong glue, like Welder's all-purpose, or a hot glue gun if you have one. Regular model cement glue will not be strong enough to keep the top in place during the explosion.
Now, we turn to the one supply that no pyro should be without - duct tape. Cut a long strip of tape, long enough to completely cover the container from top to bottom and back again. This is where the toothpick come in - push the tape slowly over the toothpick onto the top of the container. The toothpick will mark the place where the fuse will later be inserted. Repeat the process until the container is completely covered with tape. The purpose of the tape is two-fold: first, it strengthens the container allowing more pressure to build up before it bursts and secondly, it traps any pieces of the container that might otherwise have a tendency to be ejected from the explosion. While the glue is drying, remove the toothpick and insert the fuse through the hole left behind. The fuse should fit snugly. When the glue is dry, take the whole device outside, place on the ground, light the fuse and get out of the way. If you are successful, you should soon have a visit from the neighbors.

 

 

 

 

 

 

Flash Powder

Black powder is not the only explosive agent out there - there are literally hundreds, all with different uses and characteristics. Flash powder is one such material. It was originally used to produce the bright flash for those old-time photographs. Flash powder has some pros and cons over black powder:
Pros: Flash powder is much, much easier to make. It also produces far more heat and sound than a BP explosion.
Cons: Flash powder is highly unstable. It can easily be set off by friction alone. It also produces a far more powerful explosion than BP. If you are dumb enough to hold a container of BP in your hand while it explodes, you will land up with severely burnt fingers. If you repeat the experiment with flash powder, you will land up with no fingers at all. I'm not kidding. I have personally seen 40 grams of flash powder in a cherry bomb leave a crater a half foot deep in my backyard.

Ingredients                                 

There are several compositions of flash powder. The safest (relatively speaking) is Potassium Perchlorate (KClO4) and Aluminum powder. This produces a powder which is relatively stable, but slightly less potent than the other compositions. Flash powder can also be made from Potassium Chlorate and Aluminum powder. This powder produces an extremely bright flash, and a window-rattling bang, but it is very sensitive to friction. Just staring at it long enough will set it off. I suggest you stick to the perchlorate version.

Making Flash Powder

The ratios by weight for flash powder are 70:30 of KClO4 and Al powder. The powder is mixed as follows:

1.     Place 70 grams of KClO4 on a sheet of newspaper. Gently crush the powder with a rolling pin to break up any crystals.

2.     Slowly sprinkle 30 grams of Aluminum powder on top of the KClO4.

3.     Pick up the top left corner of the paper and gently roll the mixture towards you. Pick up the bottom right corner of the paper and gently roll the mixture back to the center.

4.     Repeat this rolling procedure with all four corners until the powders are thoroughly mixed. Take your time, repeat at least forty times.

5.     Slowly pour the mixture into a clearly labeled ZipLoc bag.

Cherry Bombs

These are fun little devices. They look cool, make an extremely bright flash and an earsplitting bang. They are also fairly easy to make.
Requirements: Ping-Pong (table tennis) balls, duct tape, box-cutter, strips of newspaper, liquid starch.
Method: cut a small hold about a centimeter in diameter in the ping-pong ball with the box cutter. Fill the ball about one-third with flash powder. Cover the hole with duct tape.
Cut a piece of newspaper into strips about 30 cm by 1.5 cm. Dip a strip of paper into a container of liquid starch, and wrap around the ball. Repeat until the ball is covered with at least three layers of paper.
Leave the ball outside to dry in direct sunlight for 24 to 48 hours, until the paper is completely solid. If you want to add a classic touch, paint the ball red with a can of regular spray paint.
Carefully drill a small hole in the ball for a fuse. It is best to use a hand drill for this purpose, to avoid sparks.
Insert the fuse. Attach the fuse to the surface of the ball with a little model cement or hot glue. (Don't use too much glue, or it will tend to smother the fuse).

Many people know that explosives are used in Mining, Building Demolition, Pyrotechnics and even Construction. Many would be surprised to know about some of the unusual uses of explosives. Did you know that explosives were used to carve Mount Rushmore? Explosives are also used to control Avalanches and are used in the backcountry for Trail Maintenance. Explosives are even used in Medicine to break-up kidney stones!

In the United States, explosives are primarily used in Mining, Quarrying and Construction as shown below:

Nationwide explosive use:
Coal Mining 67%
Non-metal mines and quarries 14%
Metal mining 10%
Construction 7% and
Miscellaneous 3%

The Many Uses of Explosives:
Aerospace - As in Ejector Seats and Separation Devices for Rocket Boosters

Agriculture - Farmers use explosives to break up boulders, blow tree stumps, felling trees and loosening soil.

Aggregate Blasting

Art - As in Metalclad art and large projects such as Mountain carving

Automotive Restraint Systems - to inflat Airbags


Avalanche Control

Coal Blasting

Commercial and Industrial Products - Door Systems, for example

Construction

Demilitarization Work


Demolition - The quantities of explosive used on this type of operation vary, depending on the size, construction and location, of the structure to be demolished. Whether it be Bridges, Buildings, Chimneys, or Towers.

Diamond Manufacturing - Jewelry grade and Very fine industrial-type diamonds used for grinding and polishing are produced by the carefully controlled action of explosives on carbon.

Emergencies at Sea - project lifelines to ships in distress off storm-beaten shores

Excavation - to dig Foundations and clear Underwater Channels/Dredging

Fire Fighting - Along fire paths to cut off oxygen to a large fire and to extinguish oil well fires.

Fire Suppression Systems

Fireworks (See Pyrotechnics)

Food Preparation - Meat Tenderizing

Forestry - Trail Blazing

Hazardous Wastes - for destruction of some hazardous waste materials

Ice Jams

Law Enforcement and Security - used in Exploding Dye Capsules and other Security Systems.

Logging - For cutting and removing timber

Manufacturing - Man-made diamonds

Medical Uses
Medicines
Fracturing Kidney and Gall Stones

Metalworking
Hardening of Metals - Including railway frogs and hardening of crusher wear parts, shovel teeth, ripper shanks, and speciality wear components such as striker bars and striker plates for mills. The explosive depth hardening process will take manganese steel from 350 brinell up to 490 brinell after two shots. The EDH process increases wear life substantially.

Metal-cladding - Explosives are sometimes used to bond various metals to each other.

Mining and Quarrying - Explosives are used to break up rock and displace large quantities of earth.

Nail guns

Oil Well Perforation

Pile driving - When pile drivers are not available, exploding dynamite on an iron plate placed on top of the piles can do their work.

Pyrotechnics
Display fireworks
Theatrical Special Effects

Quarrying

Railroads - Hardening and removing track parts

Riveting - Blind rivets are needed when space limitations make conventional rivets impractical. Explosive riveting is an engineering practice.

Rocketry

Seismic Exploration

Signal Lights

Soil Compaction - For large-scale construction projects, soil compaction is often accomplished with the use of explosives.

Sport Shooting - Gunpowder (blackpowder and smokeless powder) is used for shooting purposes, such as muzzle-loading handguns and rifles, or events where re-enactments of historical battles involve the use of muzzle-loading muskets and cannon.

Tools - Hand tools

Tunneling

Welding - Explosives jigs are often used to weld large diameter Pipelines