LEC8: Explosives, Pyrotechnics, and Chemical Warfare

It involves high-energy and high-toxicity chemical systems

Why is the explosives, pyrotechnics, and chemical warfare industry one of the most sensitive areas in CPI?

Explosives

Its main function is the rapid release of gas, heat, and pressure. Examples include:
mining, quarrying, tunneling, demolition, blasting

Pyrotechnics

Its main function is the controlled production of light, heat, sound, smoke, gas, or color. Examples include:
fireworks, flares, signal devices, stage effects, etc

Chemical Warfare Agents

These are toxic chemicals intended to harm through physiological action

fuel, oxidizing material

The earliset energetic materials were based on the concept of combining _____ and _____ so that combustion can occur rapidly.

Black powder

One of the earliest known energetic mixtures and became important in mining, warfare, and fireworks.

• combustion rate

• confinement

• particle size

• mixing quality

• oxygen availability

What are the parameters / properties fundamental in the chem engg aspect of this industry?

Alfred Nobel 1867

Who developed dynamite (stabilized nitroglycerin)?

1675 Strasbourg Agreement

First agreement that prohibited poison bullets

• Hague Convention

• 1926 Geneva Protocol

This followed the 1675 Strasbourg Agreement

Modern Chemical Weapons Convention

The 1925 Geneva protocol only banned the usage of cwa in wars. This convention aimed to eliminate it entirely including production and development.

rate of energy release

The main engineering concern in explosives and pyrotechnics is not only the total energy content, but also the _____.

Deflagration

Rapid burning where the reaction front travels below the speed of sound in the material. Examples include:

low explosives, propellants, many pyrotechnic effects

Detonation

Supersonic reaction front driven by a shock wave. Examples include:

high explosives and blasting applications

TRUE

TRUE OR FALSE:
Deflagration → pushes → propulsion, gas generation, pyrotechnic effects

Detonation → shatters → strong shock wave need, rock fragmentation

• strength or energy output

• velocity of detonation

• brisance

• sensitivity

• stability

• water resistance

• density

• fume characteristics

What are the important properties of explosives and pyrotechnics?

Strength or energy output

capacity to do mechanical work | determines rock-breaking or pressure-generating ability

Velocity of detonation

speed of shock-front propagation | affects shattering effect and blast performance

Brisance

shattering power | important in demolition and rock fragmentation

Sensitivity

ease of initiation by heat, shock, friction, or impact | critical for safe handling and storage

Stability

resistance to decomposition during storage | determines shelf life and safety

Water resistance

ability to perform in wet environments | important in mining and quarrying

Density

Mass per unit volume | affects energy concentration

Fume characteristics

Gases produced after reaction | important for underground mining and occupational safety

• Reaction mode

• Sensitivity

• Use

• Physical form

• Composition

What are the different classification basis of explosives

Low and high explosives

What are the types of explosives according to reaction mode?

Primary, secondary, tertiary

What are the types of explosives according to sensitivity?

• Industrial

• Military

• Propellant

• Pyrotechnic

What are the types of explosives according to use?

• Solid

• Slurry

• Emulsion

• Gel

• Powder

• Cast

• Pressed

What are the types of explosives according to physical form?

Single-compound or composite

What are the types of explosives according to composition?

1. Raw material qualification

2. Controlled chemical processing or formulation

3. Forming or packaging

4. Quality assurance testing

5. Licensed storage and transport

6. Field use under authorized control

Industrial Process Flow for Explosives

Controlled redox reaction between a fuel and an oxidizer

What is the basic chemistry of pyrotechnics?

Fuel

Part of the pyrotechnic that releases energy during combustion

Color-producing material

Part of the pyrotechnic that produces characteristic flame color

Metallic fuel or spark agent

Part of the pyrotechnic that produces brightness, sparks, or heat

Smoke-forming material

Part of the pyrotechnic that produces visible smoke for signaling or screening

Delay material

Part of the pyrotechnic that controls timing between ignition and effect

Stabilizer or moisture-control additive

Part of the pyrotechnic that improves storage stability and safety

Stars

pellets containing metal salts, fuel, oxidizing agent, and binder

strontium-containing compounds

Common metal ion source if color is red

sodium-containing compounds

Common metal ion source if color is yellow

barium-containing compounds

Common metal ion source if color is green

copper-containing compounds

Common metal ion source if color is blue

calcium-containing compounds

Common metal ion source if color is orange

hot metal particles such as magnesium, aluminum, or titanium systems

Common metal ion source if color is white/silver brightness