explosives (explosives) unstable chemical compounds or mixtures are called, extremely quickly passing under the influence of a certain impulse into other stable substances with the release of a significant amount of heat and a large volume of gaseous products, which are under very high pressure and, expanding, perform one or another mechanical work.

Modern explosives are either chemical compounds (hexogen, trotyl, etc..), or mechanical mixtures(ammonium nitrate and nitroglycerine explosives).

Chemical compounds obtained by treatment with nitric acid (nitration) of various hydrocarbons, i.e., the introduction of substances such as nitrogen and oxygen into the hydrocarbon molecule.

Mechanical mixtures are made by mixing substances rich in oxygen with substances rich in carbon.

In both cases, oxygen is in a bound state with nitrogen or chlorine (the exception is oxyliquites where oxygen is in the free unbound state).

Depending on the quantitative content of oxygen in the explosive, the oxidation of combustible elements in the process of explosive transformation can be complete or incomplete, and sometimes oxygen may even remain in excess. In accordance with this, explosives are distinguished with excess (positive), zero and insufficient (negative) oxygen balance.

The most beneficial are explosives that have a zero oxygen balance, since carbon is completely oxidized to CO 2, and hydrogen to H 2 O, resulting in the release of the maximum possible amount of heat for a given explosive. An example of such an explosive is dinaphthalite, which is a mixture ammonium nitrate and dinitronaphthalene:

At excess oxygen balance the remaining unused oxygen combines with nitrogen, forming highly toxic oxides of nitrogen, which absorb some of the heat, which reduces the amount of energy released during the explosion. An example of an explosive with excess oxygen balance is nitroglycerine:

On the other hand, when insufficient oxygen balance not all carbon goes into carbon dioxide; some of it is oxidized only to carbon monoxide. (CO) which is also poisonous, although to a lesser extent than nitrogen oxides. In addition, some of the carbon may remain in solid form. The remaining solid carbon and its incomplete oxidation only to CO lead to a decrease in the energy released during the explosion.

Indeed, during the formation of one gram-molecule of carbon monoxide, only 26 kcal/mol heat is released, while during the formation of a gram-molecule of carbon dioxide, 94 kcal/mol.

An example of an explosive with a negative oxygen balance is TNT:

In real conditions, when the explosion products perform mechanical work, additional (secondary) chemical reactions occur and the actual composition of the explosion products differs somewhat from the calculated schemes, and the amount of toxic gases in the explosion products changes.

Classification of explosives

Explosives may be in gaseous, liquid and solid state or in the form of mixtures of solid or liquid substances with solid or gaseous substances.

At present, when the number of different explosives is very large (thousands of items), their division is only physical condition completely insufficient. Such a division says nothing about the performance (power) of explosives, by which it would be possible to judge the scope of one or another of them, or about the properties of explosives, by which one could judge the degree of danger of their handling and storage. . Therefore, three other classifications of explosives are currently accepted.

According to the first classification all explosives are divided according to their power and scope into:.

A) increased power (heater, hexogen, tetryl);

B) normal power (TNT, picric acid, plastites, "tetritol, rocky ammonites, ammonites containing 50-60% TNT, and gelatinous nitroglycerin explosives);

C) reduced power (ammonium nitrate explosives, except for those mentioned above, powdered nitroglycerin explosives and chloratites).

3. Throwable explosives(smoky powders and smokeless pyroxylin and nitroglycerin powders).

This classification, of course, does not contain all the names of explosives, but only those that are mainly used in blasting. In particular, under the general name of ammonium nitrate explosives there are dozens of different compositions, each with its own separate name.

Second classification divides explosive according to their chemical composition:

1. Nitro compounds; substances of this type contain two to four nitro groups (NO 2); these include tetryl, trotyl, hexogen, tetritol, picric acid and dinitronaphthalene, which is part of some ammonium nitrate explosives.

2. Nitroesters; substances of this type contain several nitrate groups (ONO 2). These include heating elements, nitroglycerin explosives and smokeless powders.

3. Salts of nitric acid- substances containing the NO 3 group, the main representative of which is ammonium (ammonium) nitrate NH 4 NO 3, which is part of all ammonium nitrate explosives. This group also includes potassium nitrate KNO 3 - the basis of black powder, and sodium nitrate NaNO 3, which is part of nitroglycerin explosives.

4. Salts of hydronitrous acid(HN 3), of which only lead azide is used.

5. Salts of fulminic acid(HONC), of which only mercury fulminate is used.

6. Salts of chloric acid, the so-called chloratites and perchloratites, - explosives, in which the main component - the carrier of oxygen is potassium chlorate or perchlorate (KClO 3 and KClO 4); now they are used very rarely. Apart from this classification is an explosive called oxyliquit.

According to the chemical structure of the explosive, one can also judge its main properties:

Sensitivity, resistance, the composition of the explosion products, therefore, the power of the substance, its interaction with other substances (for example, with the shell material) and a number of other properties.

The nature of the bond between nitro groups and carbon (in nitro compounds and nitro esters) determines the sensitivity of the explosive to external influences and their stability (retention of explosive properties) under storage conditions. For example, nitro compounds, in which the nitrogen of the NO 2 group is bonded directly to carbon (C-NO 2), are less sensitive and more stable than nitro esters, in which nitrogen is bonded to carbon through one of the oxygens of the ONO 2 group (C-O-NO 2 ); such a bond is less strong and makes the explosive more sensitive and less resistant.

The number of nitro groups contained in the explosive characterizes the power of the latter, as well as the degree of its sensitivity to external influences. The more nitro groups in an explosive molecule, the more powerful and sensitive it is. For example, mononitrotoluene(having only one nitro group) is an oily liquid that does not have explosive properties; dinitrotoluene, containing two nitro groups, is already an explosive, but with weak explosive characteristics; and finally trinitrotoluene (TNT), having three nitro groups, is an explosive that is quite satisfactory in terms of power.

Dinitro compounds are of limited use; Most modern explosives contain three or four nitro groups.

The presence of some other groups in the composition of the explosive also affects its properties. For example, additional nitrogen (N 3) in hexogen increases the sensitivity of the latter. The methyl group (CH 3) in TNT and tetryl contributes to the fact that these explosives do not interact with metals, while the hydroxyl group (OH) in picric acid is lung cause the interaction of a substance with metals (except tin) and the appearance of the so-called picrates of a particular metal, which are explosives that are very sensitive to impact and friction.

Explosives obtained by replacing hydrogen with a metal in hydrazoic or fulminic acid cause the extreme fragility of intramolecular bonds and, consequently, the special sensitivity of these substances to mechanical and thermal external influences.

At blasting in everyday life, a third classification of explosives is adopted: - according to the admissibility of their use in certain conditions.

According to this classification, the following three main groups are distinguished:

1. Explosives approved for open work.

2. Explosives approved for underground work in conditions that are safe, if possible, from an explosion of firedamp and coal dust.

3. Explosives approved only for conditions that are dangerous for the possibility of a gas or dust explosion (safety explosives).

The criterion for assigning an explosive to one or another group is the amount of poisonous (harmful) gases released during the explosion and the temperature of the explosion products. So, TNT, due to the large amount of poisonous gases formed during its explosion, can only be used in open works ( construction and quarry mining), while ammonium nitrate explosives are allowed both in open and underground works in conditions that are not hazardous in terms of gas and dust. For underground work, where the presence of exploding gas and dust-air mixtures is possible, only explosives with a lower temperature of the explosion products are allowed.

Since the invention of gunpowder, the world race for the most powerful explosives has not stopped. This is true even today, despite the appearance of nuclear weapons.

1 Hexogen is an explosive drug

Back in 1899, for the treatment of inflammation in the urinary tract, the German chemist Hans Genning patented the drug hexogen, an analogue of the well-known hexamine. But soon the doctors lost interest in him due to side intoxication. Only thirty years later it became clear that hexogen turned out to be the most powerful explosive, moreover, more destructive than TNT. A kilogram RDX explosive will produce the same destruction as 1.25 kilograms of TNT.

Specialists in pyrotechnics mainly characterize explosives by explosiveness and brisance. In the first case, one speaks of the volume of gas released during the explosion. Like, the larger it is, the more powerful the explosiveness. Brisance, in turn, depends already on the rate of formation of gases and shows how explosives can crush surrounding materials.

10 grams of RDX emit 480 cubic centimeters of gas during an explosion, while TNT - 285 cubic centimeters. In other words, RDX is 1.7 times more powerful than TNT in explosiveness and 1.26 times more dynamic in blasting.

However, the media most often uses a certain average indicator. For example, the atomic charge "Baby", dropped on August 6, 1945 on the Japanese city of Hiroshima, is estimated at 13-18 kilotons of TNT. Meanwhile, this does not characterize the power of the explosion, but indicates how much TNT is needed to release the same amount of heat as during the indicated nuclear bombardment.

In 1942, the American chemist Bachmann, while conducting experiments with RDX, accidentally discovered a new substance, HMX, in the form of an impurity. He offered his find to the military, but they refused. Meanwhile, a few years later, after it was possible to stabilize the properties of this chemical compound, the Pentagon nevertheless became interested in HMX. True, it was not widely used in its pure form for military purposes, most often in a casting mixture with TNT. This explosive was called "Octolome". It turned out to be 15% more powerful than hexogen. As for its effectiveness, it is believed that one kilogram of HMX will produce as much destruction as four kilograms of TNT.

However, in those years, the production of HMX was 10 times more expensive than the production of RDX, which hindered its production in the Soviet Union. Our generals have calculated that it is better to produce six shells with hexogen than one with octol. That is why the explosion of an ammunition depot in the Vietnamese Quy Ngon in April 1969 cost the Americans so dearly. Then a Pentagon spokesman said that due to the sabotage of the partisans, the damage amounted to 123 million dollars, or about 0.5 billion dollars in current prices.

In the 80s of the last century, after Soviet chemists, including E.Yu. Orlov, developed an efficient and inexpensive technology for the synthesis of HMX, in large volumes it began to be produced in our country.

3 Astrolite - good, but smells bad

In the early 60s of the last century, the American company EXCOA presented a new explosive based on hydrazine, claiming that it was 20 times more powerful than TNT. The Pentagon generals who arrived for the test were knocked off their feet by the terrible smell of an abandoned public toilet. However, they were willing to endure it. However, a number of tests with air bombs filled with astrolite A 1-5 showed that the explosive was only twice as powerful as TNT.

After Pentagon officials rejected this bomb, EXCOA engineers proposed a new version of this explosive already under the ASTRA-PAK brand, moreover, for digging trenches using the directed explosion method. In the commercial, a soldier poured water on the ground in a thin stream, and then detonated the liquid from cover. And a man-sized trench was ready. On its own initiative, EXCOA produced 1000 sets of such explosives and sent them to the Vietnamese front.

In reality, everything ended sadly and anecdotally. The resulting trenches exuded such a disgusting smell that the American soldiers sought to leave them at any cost, regardless of orders and danger to life. Those who remained lost consciousness. Unused kits were sent back to the EXCOA office at their own expense.

4 Explosives that kill their own

Along with hexogen and octogen, hard-to-pronounce tetranitropentaerythritol, which is often called PETN, is considered a classic explosive. However, due to its high sensitivity, it has not been widely used. The fact is that for military purposes, it is not so much explosives that are more destructive than others that are important, but those that do not explode from any touch, that is, with low sensitivity.

Americans are especially meticulous about this issue. It was they who developed the NATO standard STANAG 4439 for the sensitivity of explosives that can be used for military purposes. True, this happened after a series of grave incidents, including: the explosion of a warehouse at the American Air Force Base Bien Ho in Vietnam, which cost the lives of 33 technicians; the disaster on board the USS Forrestal, which resulted in damage to 60 aircraft; detonation in the storage of aircraft missiles aboard the aircraft carrier Oriskany (1966), also with numerous casualties.

5 Chinese destroyer

In the 80s of the last century, the substance tricyclic urea was synthesized. It is believed that the first to receive this explosive were the Chinese. Tests showed the enormous destructive power of "urea" - one kilogram of it replaced twenty-two kilograms of TNT.

Experts agree with such conclusions, since the “Chinese destroyer” has the highest density of all known explosives, and at the same time has the highest oxygen ratio. That is, during the explosion, all material is completely burned. By the way, for TNT it is 0.74.

In reality, tricyclic urea is not suitable for military operations, primarily due to poor hydrolytic stability. The very next day, with standard storage, it turns into mucus. However, the Chinese managed to get another "urea" - dinitrourea, which, although worse in explosiveness than the "destroyer", is also one of the most powerful explosives. Today it is produced by the Americans at their three pilot plants.

6 Pyromaniac's Dream - CL-20

The CL-20 explosive is currently positioned as one of the most powerful. In particular, the media, including Russian ones, claim that one kg of CL-20 causes destruction, which requires 20 kg of TNT.

Interestingly, the Pentagon allocated money for the development of the CL-20 only after the American press reported that such explosives had already been made in the USSR. In particular, one of the reports on this topic was called like this: “Perhaps this substance was developed by the Russians at the Zelinsky Institute.”

In reality, as a promising explosive, the Americans considered another explosive, first obtained in the USSR, namely diaminoazoxyfurazan. Along with high power, which significantly exceeds octogen, it has low sensitivity. The only thing holding back its widespread use is the lack of industrial technology.

It's power, you understand? The power in matter. Matter has tremendous power. I ... I feel to the touch that everything is teeming in her ... And all this is restrained ... with an incredible effort. It is worth loosening from the inside - and bam! - decay. Everything is an explosion.

Karel Capek, Krakatit

The semi-crazy chemical genius engineer Prokop gave in this epigraph a very precise, albeit peculiar, definition of explosives. We will talk about these substances, which largely determined the development of human civilization, in this article. Of course, we will not only talk about the military use of explosives - the scope of its use is so wide that it does not fit into some kind of template "from and to". You and I have to figure out what an explosion is, get acquainted with the types of explosives, remember the history of their appearance, development and improvement. Do not stand aside and curious or just interesting information anything to do with explosions.

For the first time in my author's practice, I have to make a warning - there will be no recipes for the manufacture of explosives, descriptions of technology and layout diagrams of explosive devices in the article. Hope for understanding.

What is an explosion?

- And here is the explosion in Grottup, - said the old man: in the picture - clubs of pink smoke, thrown out by a sulfur-yellow flame high up, to the very edge; torn human bodies hang terribly in the smoke and flames. “More than 5,000 people died in that explosion. It was a great misfortune,” the old man sighed. This is my last picture.

Karel Capek, Krakatit

The answer to this seemingly very simple question is not as simple as it might seem at first glance. The most general and precise definition of an explosion does not exist until today. Academic reference books and encyclopedias give a very vague definition of the type "an uncontrolled fast physical and chemical process with the release of significant energy in a small volume." The weakness of this definition is that no quantitative criteria are specified.

International sign "Caution! Explosive". Laconic and extremely clear.

The volume, the amount of energy released and the flow time - all these quantities can, of course, be brought to the concept of "minimum specific power", which will determine the limit above which the process can be considered explosive. But it just so happened that no one really needs such accuracy of definitions - the military, geologists, pyrotechnicians, nuclear physicists, astrophysicists, technologists have their own explosion criteria. The artilleryman simply will not have a question whether to consider the result of the operation of a high-explosive fragmentation projectile as an explosion, and an astrophysicist with a similar question regarding a supernova will generally shrug his shoulders in bewilderment.

Explosions differ in the physical nature of the energy source and how it is released. To highlight the chemical explosions that interest us, let's try to figure out what kind of explosions still happen.

thermodynamic explosion- a fairly large category of fast processes with the release of thermal or kinetic energy. For example, if you increase the pressure of a gas in a sealed vessel, then sooner or later the vessel will collapse and an explosion will occur. And if a sealed vessel with a superheated liquid under pressure is quickly opened, then an explosion will occur due to pressure release, instantaneous boiling of the liquid and the formation of shock waves.

Kinetic explosion- conversion of the kinetic energy of a moving material body into thermal energy during sudden braking. The fall of the fireball to the Earth is a quite characteristic example of a kinetic explosion. The impact of an armor-piercing projectile blank on a tank's armor could also be considered a kinetic explosion, but here everything is somewhat more complicated - the explosive nature of the interaction is ensured not only by the purely thermal effect of the impact. Free electrons in the metal of the projectile, moving at the same speed, continue to move by inertia during sharp braking, forming huge currents in the conductor.

The destruction of the 4th power unit of the Chernobyl nuclear power plant is a typical thermodynamic explosion.

electric explosion- the release of thermal energy during the passage of the so-called "shock" currents in the conductor. Here, the explosive nature of the process is determined by the resistance of the conductor and the magnitude of the passing current. For example, a 100 microfarad capacitor charged up to 300 V accumulates an energy of 4.5 J. If you close the terminals of the capacitor with a thin wire, this energy will be released on the wire in the form of heat in tens of microseconds, developing a power of tens or even hundreds of kilowatts. In this case, the wire, of course, will evaporate - that is, an explosion will occur. A lightning discharge in a thunderstorm can also be considered an electrical explosion.

Nuclear explosion is the process of releasing the intranuclear energy of atoms under uncontrolled nuclear reactions. Here, energy is released not only in the form of heat - the spectrum of radiation in the electromagnetic range during a nuclear explosion is truly colossal. In addition, the energy nuclear explosion carried away by fission fragments or fusion products, fast electrons and neutrons.

The concept of an explosion among astrophysicists is unimaginable from the standpoint of terrestrial scales - here we are talking about the release of energy in such quantities that humanity will certainly not produce over the entire period of its existence. Thanks to the explosions supernovae of the first and second generation, which caused the release of heavy elements, appeared solar system, on the third planet of which life could originate. And if you remember the theory big bang, it is safe to say that not only earthly life, but our entire universe owes its existence to the explosion.

chemical explosion

Thermochemistry does not exist. Destruction. Destructive chemistry, that's what. This is a huge thing, Tomesh, from a purely scientific point of view.

Karel Capek, Krakatit

Well, now we seem to have decided on the types of explosions that we will not consider further. Let's move on to the subject of interest to us - the widely known chemical explosions.

A hundred-ton chemical test explosion at the Alamogordo nuclear test site.

chemical explosion- this is the process of converting the internal energy of molecular bonds into thermal energy during the rapid and uncontrolled flow of chemical reactions. But in this definition we find the same problem as with the definition of an explosion in general - there is no consensus on what chemical processes can be considered an explosion.

In the opinion of most experts, the most stringent criterion for a chemical explosion is the propagation of a reaction due to the detonation process, and not deflagration.

Detonation is the supersonic propagation of a compression front with an accompanying exothermic reaction in the substance. The mechanism of detonation is that as a result of the onset chemical reaction stands out a large number of thermal energy and gaseous products under high pressure, causing a shock wave. When its front passes through the substance, a shock occurs and the temperature rises sharply (in physics, this phenomenon is described by an adiabatic process), initiating a further chemical reaction. Thus, detonation is a self-sustaining mechanism of the fastest possible (avalanche) involvement of a substance in a chemical reaction.

The ignition of a match head is thousands of times slower than the slowest explosion.

On a note: detonation velocity is one of the most important characteristics of an explosive. For solid explosives, it ranges from 1.2 km/s to 9 km/s. The higher the detonation velocity, the higher the pressure in the seal zone and the more effective the explosion.

Deflagration- subsonic redox process, in which the reaction front moves due to heat transfer. That is, we are talking about the well-known process of combustion of a reducing agent in an oxidizing agent. The speed of propagation of the combustion front is determined not only by the calorific value of the reaction and the efficiency of heat transfer in the substance, but also by the mechanism of access of the oxidizer to the reaction zone.

But here, too, not everything is clear. For example, a powerful jet of combustible gas in the atmosphere will burn in a rather complicated way - not only over the surface of the gas jet, but also in that part of the volume where air will be sucked in due to the jet effect. In this case, detonation processes are also possible - a kind of "pop" with the breakdown of the flame.

This is interesting: The combustion laboratory of the Research Institute of Physics, where I once worked, struggled for more than two years on the problem of controlled detonation of a hydrogen torch. In those days, it was jokingly called the "Laboratory of combustion and, if possible, explosion."

From all that has been said, one important conclusion should be drawn - there are very different combinations of combustion and detonation processes and transitions in one direction or another. For this reason, for simplicity, chemical explosions usually include various fast exothermic processes without specifying their nature.

Necessary terminology

- What are you, what are the numbers! First try... fifty percent starch... and the crasher shattered; one engineer and two laboratory assistants... also shattered. Don't believe? Experience two: Trauzl's block, ninety percent Vaseline, and - boom! The roof was blown off, one worker was killed; only cracklings remained from the block.

Karel Capek, Krakatit

Protective sapper suit. It produces the neutralization of explosive devices of unknown design.

Before we move on to a direct acquaintance with explosives, we should understand a little about some of the concepts associated with this class of chemical compounds. All of you have probably heard the terms "high-explosive charge" and "blasting explosives". Let's see what they mean.

explosiveness- the most general characteristic of an explosive, which determines the measure of its destructive effectiveness. Explosiveness directly depends on the amount of gaseous products released during the explosion.

In the numerical assessment of explosiveness, various methods are used, the most famous of which is Trauzl test. The test is carried out by detonating a 10 gram charge placed in a hermetically sealed cylindrical lead container (sometimes referred to as the Trauzl bomb). When the container explodes, it inflates. The difference between its volumes before and after the explosion, expressed in cubic centimeters, is the measure of explosiveness. Often the so-called comparative explosiveness, expressed as the ratio of the results obtained to the results of the explosion of 10 grams of crystalline TNT.

On a note: comparative explosiveness should not be confused with the TNT equivalent - these are completely different concepts.

Such breaks in the shell indicate a low charge brisance.

Brisance- the ability of explosives to produce during the explosion crushing of a solid medium in close proximity to the charge (several of its radii). This characteristic depends primarily on the physical state of the explosive (density, uniformity, degree of grinding). With an increase in density, the brisance increases simultaneously with an increase in the detonation velocity.

Brisance can be adjusted within wide limits by mixing the explosive with so-called phlegmatizers- chemical compounds incapable of explosion.

To measure brisance, in most cases, indirect Hess test, at which a charge weighing 50 grams is placed on a lead cylinder of a certain height and diameter, undermined, and then the height of the cylinder compressed by the explosion is measured. The difference between the heights of the cylinder before and after the explosion, expressed in millimeters, is the measure of brisance.

However, the Hess test is not suitable for testing explosives with high brisance - a charge of 50 grams simply destroys the lead cylinder to the ground. For such cases, use Brisantometer Kasta with a copper cylinder called crasher.

Such an explosion is very effective, but, as a rule, inefficient.
veins - too much energy was spent on heating the smoke cloud.

On a note: explosiveness and brisance are quantities that are not related to each other. Once, in my early youth, I was fond of the chemistry of explosives. And one day, a few grams of acetone peroxide received by me spontaneously detonated, destroying the faience crucible to the state of the smallest dust that covered the table with a thin layer. At that time I was literally a meter away from the explosion, but I was not injured at all. As you can see, acetone peroxide has excellent brisance, but low explosiveness. The same amount of high-explosive explosive could lead to barotrauma and even shell shock.

Sensitivity - a characteristic that determines the probability of an explosion with some particular impact on an explosive. Most often, this value is presented as the minimum value of the impact, which leads to a guaranteed explosion under certain standard conditions.

There are many different methods for determining a particular sensitivity (impact, friction, heating, spark discharge, backache, detonation). All these types of sensitivity are extremely important for organizing the safe production, transportation and use of explosives.

This is interesting: sensitivity records belong to very simple chemical compounds. Nitrogen iodide (aka triiodine nitride) I3N in its dry form detonates from a flash of light, from rubbing with a feather, from slight pressure or heat, even from a loud sound. This is perhaps the only explosive that detonates from alpha radiation. And a crystal of xenon trioxide - the most stable of xenon oxides - is capable of detonating from its own weight if its mass exceeds 20 mg.

Explosive welding gives such a picture of the seam on the cut. Well visible wave
figurative structure formed by a standing shock wave in detail.

Sensitivity to detonation is distinguished in a special term - susceptibility, that is, the ability of an explosive charge to explode when exposed to the explosion factors of another charge. Most often, the susceptibility is expressed in terms of the mass of mercury fulminate required to guarantee the detonation of the charge. For example, for trinitrotoluene, the susceptibility is 0.15 g.

There is another very important concept associated with explosives - critical diameter. This is the smallest diameter of a cylindrical charge at which the propagation of the detonation process is possible.

If the charge diameter is less than the critical one, then detonation either does not occur at all or decays as its front moves along the cylinder. It should be noted that the rate of detonation of a certain explosive is far from constant - with an increase in the diameter of the charge, it increases to a value characteristic of a given explosive and its physical state. The charge diameter at which the detonation velocity becomes constant is called limiting diameter.

The critical detonation diameter is usually determined by detonating model charges with a length of at least five charge diameters. For high explosives, it is usually a few millimeters.

Volumetric explosion ammunition

Mankind got acquainted with a volumetric explosion long before the creation of the first explosive. Flour dust in mills, coal dust in mines, microscopic vegetable fibers in the air of manufactories are combustible aerosols, capable of detonation under certain conditions. One spark was enough - and huge rooms crumbled like houses of cards from a monstrous explosion of dust almost invisible to the eye.

Volumetric explosion inside the car leads to such consequences.

Such a phenomenon, sooner or later, should have attracted the attention of the military - and, of course, it did. There is a type of munition that uses the spraying of a combustible substance in the form of an aerosol and undermining the resulting gas cloud - volumetric explosion munitions (sometimes called thermobaric munitions).

The principle of operation of a volumetric detonating air bomb consists in a two-stage detonation - first, one explosive charge sprays a combustible substance in the air, then the second charge detonates the resulting fuel-air mixture.

A volumetric explosion has an important feature that distinguishes it from the detonation of a concentrated charge - the explosion of a fuel-air mixture has a much greater high-explosive effect than that of a classical charge of the same mass. Moreover, as the size of the cloud increases, the explosiveness increases non-linearly. Large-caliber volumetric detonating bombs can create an explosion comparable in energy to a tactical nuclear charge low power.

The main damaging factor of a volumetric explosion is a shock wave, since the blasting action here is indistinguishable from zero.

Information about thermobaric ammunition, distorted beyond recognition by illiterate journalists, leads a knowledgeable person into a righteous rage, and an ignorant one into panic horror. It’s not enough for journalism dreamers that they called a volumetric detonation aerial bomb the ridiculous term “vacuum bomb”. They follow the instructions of Joseph Goebbels and pile up such wild nonsense that some people believe in it.

Testing a thermobaric explosive device. It seems that he is still very far from a combat model.

“... The principle of operation of this terrible weapon, approaching the power of a nuclear bomb, is based on a kind of explosion in reverse. When this bomb explodes, oxygen is instantly burned, a deep vacuum is formed, deeper than in open space. All surrounding objects, people, cars, animals, trees are instantly drawn into the epicenter of the explosion and, colliding, turn into powder ... "

Agree, the "burning of oxygen" alone clearly indicates "three classes and two corridors." And "a vacuum deeper than in outer space" clearly hints that the author of this writing is unaware of the presence in the air of 78% nitrogen, completely unsuitable for "burning". Here is perhaps the unbridled fantasy, pouring into the epicenter (sic!) People, animals and trees, causes involuntary admiration.

Classification of explosives

“Everything is an explosive ... you just have to take it properly.

Karel Capek, Krakatit

Yes, these are also explosives. But we will not discuss them, but just admire.

Chemistry and technology of explosives is still considered a field of knowledge with severely limited access to information. This state of affairs inevitably leads to a wide variety of formulations and definitions. And it is for this reason that a special commission of the United Nations adopted in 2003 the "System of Classification and Labeling of Chemical Products", harmonized at the global level. Below is the definition of explosives taken from this document.

Explosive(or mixture) - a solid or liquid substance (or mixture of substances), which is itself capable of chemical reaction with the evolution of gases at such a temperature and such pressure and at such a speed that it causes damage to surrounding objects. Pyrotechnic substances are included in this category even if they do not emit gases.

pyrotechnic substance(or mixture) - A substance or mixture of substances that is intended to produce an effect in the form of heat, fire, sound or smoke, or a combination of them, as a result of self-sustaining exothermic chemical reactions that occur without detonation.

Thus, the category of explosives traditionally includes all kinds of powder compositions capable of burning without air. Moreover, the same category includes the very firecrackers with which the people so love to please themselves on New Year's Eve. But below we will talk about "real" explosives, without which the military, builders and miners cannot imagine their existence.

Explosives are classified according to several principles - composition, physical state, form of operation of the explosion, scope.

Composition

There are two large classes of explosives - individual and composite.

Individual are chemical compounds capable of intramolecular oxidation. In this case, the molecule should not contain oxygen at all - it is enough that one part of the molecule transfers an electron to another part of it with a positive thermal output.

Energetically, a molecule of such an explosive can be represented as a ball lying in a depression on the top of a mountain. It will lie quietly until a relatively small impulse is transferred to it, after which it will roll down the mountainside, releasing energy much greater than the expended energy.

A pound of TNT in its original packaging and an ammonal charge weighing 20 kilograms.

Individual explosives include trinitrotoluene (aka TNT, tol, TNT), hexogen, nitroglycerin, mercury fulminate (mercury fulminate), lead azide.

Composite consist of two or more substances that are not chemically related. Sometimes the components of such explosives themselves are not capable of detonation, but exhibit these properties when they react with each other (usually it is a mixture of an oxidizing agent and a reducing agent). A typical example of such a two-component composite is oxyliquite (a porous combustible substance impregnated with liquid oxygen).

Composites can also consist of a mixture of individual explosives with additives that regulate sensitivity, explosiveness and brisance. Such additives can both weaken the explosive characteristics of composites (paraffin, ceresin, talc, diphenylamine) and enhance them (powders of various reactive metals - aluminum, magnesium, zirconium). In addition, there are stabilizing additives that increase the shelf life of finished explosive charges, and conditioned additives that bring the explosive to the required physical state.

In connection with the development and spread of world terrorism, the requirements for the control of explosives have become more stringent. The composition of modern explosives without fail includes chemical markers that are found in the products of the explosion and unambiguously indicate the manufacturer, as well as odorous substances that help in the detection of explosive charges by service dogs and gas chromatography devices.

The physical state

The American bomb BLU-82/B contains 5700 kg of ammonal. This is one of the most powerful non-nuclear bombs.

This classification is very broad. It includes not only three states of matter (gas, liquid, solid), but also all kinds of dispersed systems (gels, suspensions, emulsions). A typical representative of liquid explosives, nitroglycerin, when nitrocellulose is dissolved in it, turns into a gel known as “explosive jelly”, and when this gel is mixed with a solid absorbent, solid dynamite is formed.

The so-called "explosive gases", that is, mixtures of hydrogen with oxygen or chlorine, are practically not used either in industry or in military affairs. They are extremely unstable, extremely sensitive and do not allow accurate explosive action. There are, however, so-called volume explosion munitions in which the military is showing great interest. They do not fall into the category of gaseous explosives, but are close enough to it.

Most modern industrial compositions are aqueous suspensions of composites consisting of ammonium nitrate and combustible components. Such compositions are very convenient for transportation to the place of blasting and pouring into boreholes. And the widely used Sprengel formulations are stored separately and prepared directly at the place of application in required quantity.

Military explosives are usually solid. The world famous trinitrotoluene melts without decomposition and therefore allows you to create monolithic charges. And no less well-known RDX and PETN decompose during melting (sometimes with an explosion), therefore, charges from such explosives are formed by pressing the crystalline mass in a wet state, followed by drying. Ammonites and ammonals used in loading ammunition are usually granulated to facilitate filling.

Explosion work form

Purified mercury fulminate is somewhat reminiscent of March snowdrifts.

To ensure the safety of storage and use, industrial and combat charges should be formed from low-sensitivity explosives - the lower their sensitivity, the better. And to undermine these charges, charges are used that are small enough so that their spontaneous detonation during storage does not cause significant damage. A typical example of this approach is the RGD-5 offensive grenade with a UZRGM fuse.

Initiators called individual or mixed explosives that are highly sensitive to simple influences (impact, friction, heating). Such substances require the release of energy sufficient to start the detonation process of high explosives - that is, a high initiating ability. In addition, they must have good flowability and compressibility, chemical resistance, and compatibility with secondary explosives.

Initiating explosives are used in a special design - the so-called blasting caps and igniter caps. They are everywhere where you need to make an explosion. And they are not subject to division into "military" and "civilian" - the method of using high explosives plays absolutely no role here.

This is interesting: tetrazole derivatives are used in automobile airbags as a source of explosive nitrogen gas release. As you can see, an explosion can not only kill, but also save a life.

This is how - flakes - looked like trinitrotoluene obtained
Heinrich Kast.

Examples of initiating explosives are mercury fulminate, lead azide, and lead trinitroresorcinate. However, initiating explosives that do not contain heavy metals are currently being actively sought and introduced. Compositions based on nitrotetrazole in combination with iron are recommended as environmentally safe. And the ammonia complexes of cobalt perchlorate with tetrazole derivatives detonate from a laser beam supplied through an optical fiber. This technology eliminates accidental detonation during the accumulation of a static charge and significantly increases the safety of blasting.

blasting explosives, as already mentioned, are of low sensitivity. Various nitro compounds are widely used as individual and mixed compositions. In addition to the familiar and well-known TNT, one can recall nitroamines (tetryl, hexogen, octogen), nitric acid esters (nitroglycerin, nitroglycol), cellulose nitrates.

This is interesting: having served faithfully for explosives of all stripes for a hundred years, trinitrotoluene is losing ground. In any case, it has not been used in the US for blasting since 1990. The reason lies in all the same environmental considerations - the products of the explosion of TNT are very toxic.

High explosives are used to equip artillery shells, aerial bombs, torpedoes, warheads of missiles of various classes, hand grenades - in a word, their military application is boundless.

We should also remember about nuclear weapons, where a chemical explosion is used to transfer the assembly to a supercritical state. However, here the word "brisant" should be used with caution - implosion lenses require just a low brisance with high explosiveness in order for the assembly to be compressed, and not crushed by an explosion. For this purpose, boratol (a mixture of TNT with barium nitrate) is used - a composition with a large outgassing, but a low detonation velocity.

Crazy Horse Memorial,
held in South Dakota and dedicated to Indian Chief Crazy Horse, carved from solid rock
using explosives.

Informal name of the airline
bombs GBU-43/B - Mother Of All Bombs. At the time of its creation, it was the largest non-nuclear bomb in the world and contained 8.5 tons of explosives.

This is interesting: The Crazy Horse Memorial, erected in South Dakota in honor of the legendary war chief of the Oglala Indian tribe, is made using explosives.

High explosive charges are used in rocket and space technology to separate the structural elements of launch vehicles and spacecraft, ejection and firing of parachutes, and emergency shutdown of engines. Aviation automation also did not ignore them - the shooting of the lantern of the cockpit of a fighter before ejection is carried out with small high-energy charges. And in the Mi-28 helicopter, such charges perform three functions at once during an emergency escape of the helicopter - firing off the blades, dropping the cabin doors and inflating the safety chambers located below the door level.

A significant amount of high explosives is consumed in mining (overburden work, mining), in construction (preparation of pits, destruction of rocks and liquidated building structures), in industry (explosion welding, hardening impulse processing of metals, stamping).

Plastite or plastid?

I'll be honest: both forms of the "folk-journalistic" name of the plastic explosive compound Composition C-4 evoke in me approximately the same feelings as "the epicenter of the explosion of a vacuum bomb."

However, why C-4? No, plastite is an explosive of monstrous destructive power, traces of which are certainly found in airports, schools and hospitals blown up by terrorists. Not a single self-respecting terrorist even touches tol or ammonal with a finger - these are children's toys compared to plastite, one matchbox of which turns a car into a fireball, and a kilogram smashes a multi-storey building into the trash.

Sticking detonators into soft C-4 briquettes is a simple matter. This is how military explosives should be - simple and reliable.

But what is a "plastid" then? Ah, so it's the name of the same super high explosive terrorists, but written by a person who wants to show that he is "in the know." Say, "plastic" is written by illiterate ignoramuses. And in general it is some kind of third person verb in the present tense. The correct spelling is plastid.

Well, now that I have poured out the accumulated bile, let's talk seriously. Neither plastite nor plastid in the understanding of explosives exists. Even before the Second World War, a whole class of plastic explosive compositions appeared - most often based on RDX or HMX. These compositions were created for civil technical work. Try, for example, to fix several TNT blocks on a vertical I-beam that needs to be destroyed. And do not forget that they should be blown up synchronously, with an accuracy of fractions of a millisecond. And with plastic compositions, everything is much simpler - he covered the beam with a substance similar to hard plasticine, stuck a couple of electric detonators into it around the perimeter - and it's in the bag.

Later, when it turned out that plastic explosives are very convenient to place, the US military became interested in them and created dozens of different formulations. And it just so happened that the most popular of all turned out to be the unremarkable Composition C-4, developed in the 1960s for army sabotage needs. But he was never a plastite. And he was never a plastid either.

History of explosives

Yes, I will unleash a storm like never before; I will give the krakatite, the liberated element, and the boat of humanity will be shattered to pieces... Thousands of thousands will perish. The nations will be cut off and the cities swept away; there will be no limit to those who have weapons in their hands and death in their hearts.

Karel Capek, Krakatit

For hundreds of years from the invention of gunpowder until 1863, mankind had no idea about the power that lies dormant in explosives. All blasting work was carried out by laying a certain amount of gunpowder, which was then set on fire with the help of a wick. With a significant high-explosive effect of such an explosion, its brisance was practically equal to zero.

Until the end of World War I, there were
gunpowder bombs were fired
would be loud and ridiculous.

Artillery shells and bombs loaded with gunpowder had an insignificant fragmentation effect. With a relatively slow increase in the pressure of powder gases, cast-iron and steel cases were destroyed along two or three lines of the lowest strength, giving a very small number of very large fragments. The probability of hitting enemy personnel with such fragments was so small that powder bombs provided mainly a demoralizing effect.

Grimaces of fate

The discovery of a chemical substance and the discovery of its explosive properties often occurred at different times. Strictly speaking, the beginning of the history of explosives could be laid in 1832, when the French chemist Henri Braconnot received a product of the complete nitration of cellulose - pyroxylin. However, no one took up the study of its properties, and there were no ways to initiate the detonation of pyroxylin at that time.

Looking back even further, one of the most common explosives, picric acid, was discovered in 1771. But at that time there was not even a theoretical possibility to detonate it - mercury fulminate appeared only in 1799, and more than thirty years remained before the first use of fulminant mercury in igniter capsules.

Start in liquid form

The history of modern explosives begins in 1846, when the Italian scientist Ascanio Sobrero first obtained nitroglycerin, an ester of glycerol and nitric acid. Sobrero quickly discovered the explosive properties of a colorless viscous liquid and therefore at first called the resulting compound pyroglycerin.

Alfred Nobel is the man who created dynamite.

Three-dimensional model of the nitroglycerin molecule.

According to modern ideas, nitroglycerin is a very mediocre explosive. In a liquid state, it is too sensitive to shock and heat, and in a solid state (cooled to 13 ° C) it is too sensitive to friction. The explosiveness and brisance of nitroglycerin strongly depend on the method of initiation, and when using a weak detonator, the explosion power is relatively small. But then it was a breakthrough - the world did not yet know such substances.

The practical use of nitroglycerin did not begin until seventeen years later. In 1863, the Swedish engineer Alfred Nobel designed a powder igniter primer that allows the use of nitroglycerin in mining. Two more years later, in 1865, Nobel creates the first full-fledged detonator cap containing mercury fulminate. Using such a detonator, you can initiate almost any high explosive and cause a full-fledged explosion.

In 1867, the first explosive suitable for safe storage and transportation appeared - dynamite. It took Nobel nine years to bring the technology of dynamite production to perfection - in 1876, a solution of nitrocellulose in nitroglycerin (or "explosive jelly") was patented, which to this day is considered one of the most powerful explosives of high explosive action. It was from this composition that the famous Nobel dynamite was prepared.

The outstanding chemist and engineer Alfred Nobel, who actually changed the face of the world and gave a real impetus to the development of modern military and, indirectly, space technology, died in 1896, having lived for 63 years. Having poor health, he was so engrossed in work that he often forgot to eat. A laboratory was built at each of his factories so that the owner who unexpectedly arrived could continue experiments without the slightest delay. He was the general director of his factories, and the chief accountant, and the chief engineer and technologist, and secretary. The thirst for knowledge was the main feature of his character: “The things I work on are really monstrous, but they are so interesting, so technically perfect, that they become doubly attractive.”

Explosive Dye

In 1868, the British chemist Frederic-August Abel, after six years of research, managed to obtain pressed pyroxylin. However, in relation to trinitrophenol (picric acid), Abel was assigned the role of "authoritative brake". Since the beginning of the 19th century, the explosive properties of picric acid salts have been known, but no one guessed that picric acid itself is capable of an explosion until 1873. Picric acid has been used as a dye for a century. In those days, when a lively test of the explosive properties of various substances began, Abel several times authoritatively stated that trinitrophenol is absolutely inert.

Three-dimensional model of the trinitrophenol molecule.

Hermann Sprengel was a German by birth.
ny, but lived and worked in the UK. It was he who gave the French
opportunity to earn money on secret melinite.

In 1873, the German Hermann Sprengel, who created a whole class of explosives, convincingly showed the ability of trinitrophenol to detonate, but then another difficulty arose - the pressed crystalline trinitrophenol turned out to be very capricious and unpredictable - it did not explode when necessary, then exploded when it was not necessary.

Picric acid appeared before the French Explosives Commission. It was found that it is the most powerful blasting substance, second only to nitroglycerin, but it is slightly let down by oxygen balance. It was also found that picric acid itself has low sensitivity, and its salts, which are formed during long-term storage, detonate. These studies marked the beginning of a complete revolution in the views on picric acid. Finally, the distrust of the new explosive was dispelled by the work of the Parisian chemist Turpin, who showed that fused picric acid changes its properties unrecognizably in comparison with a pressed crystalline mass and completely loses its dangerous sensitivity.

This is interesting: later it turned out that fusion solved problems with detonation in an explosive similar to trinitrophenol - trinitrotoluene.

Such studies, of course, were strictly classified. And in the eighties of the XIX century, when the French began to produce a new explosive called "melinite", Russia, Germany, Great Britain and the United States showed great interest in it. After all, the high-explosive action of ammunition filled with melinite looks impressive even today. Intelligence actively earned, and after a short time, the secret of melinite became an open secret.

In 1890, D. I. Mendeleev wrote to the Minister of Marine Chikhachev: “As for melinitis, the destructive effect of which surpasses all these tests, it is uniformly understood from private sources from different sides that melinitis is nothing more than cooled picric acid fused under high pressure”.

Wake up the demon

Ironically, trinitrotoluene, a “relative” of picric acid, had a similar fate. It was first obtained by the German chemist Wilbrand back in 1863, but only at the beginning of the 20th century found use as an explosive, when the German engineer Heinrich Kast took up his research. First of all, he drew attention to the technology for the synthesis of trinitrotoluene - it did not contain stages dangerous for the explosion. That alone was a huge advantage. Still fresh in the memory of Europeans were numerous horrific explosions of factories producing nitroglycerin.

Three-dimensional model of the trinitrotoluene molecule.

Another important advantage was the chemical inertness of trinitrotoluene - the reactivity and hygroscopicity of picric acid pretty much annoyed the designers of artillery shells.

The yellowish flakes of TNT obtained by Custom showed a surprisingly peaceful disposition - so peaceful that many doubted its ability to detonate. Strong blows with a hammer flattened the scales, in a fire trinitrotoluene exploded no better than birch firewood, and burned much worse. It got to the point that they tried to shoot rifles into bags of trinitrotoluene. The result was only clouds of yellow dust.

But a way to wake the dormant demon was found - for the first time this happened when a melinite checker was blown up close to the mass of trinitrotoluene. And then it turned out that if it is fused into a monolithic block, then reliable detonation is provided by a standard Nobel Nobel detonator cap No. 8. Otherwise, the melted trinitrotoluene turned out to be the same phlegmatic as before melting. It can be sawn, drilled, pressed, ground - in a word, do what you like. The melting temperature of 80°C is extremely convenient from a technological point of view - it will not leak in the heat, but it does not require special expenses for melting. Molten trinitrotoluene is very fluid, it can easily be poured into shells and bombs through the fuse hole. In general, the embodied dream of the military.

Under Kast's leadership, in 1905, Germany received the first hundred tons of new explosives. As in the case of French melinite, it was strictly classified and bore the meaningless name "TNT". But after only a year, through the efforts of the Russian officer V.I. Rdultovsky, the secret of TNT was revealed, and they began to manufacture it in Russia.

From air and water

Explosives based on ammonium nitrate were patented in 1867, but due to their high hygroscopicity, they were not used for a long time. Things got off the ground only after the development of the production of mineral fertilizers, when effective ways were found to prevent saltpeter caking.

A large number of explosives containing nitrogen discovered in the 19th century (melinite, TNT, nitromannite, pentrite, hexogen) required a large amount of nitric acid. This prompted German chemists to develop a technology for binding atmospheric nitrogen, which, in turn, made it possible to obtain explosives without the participation of mineral and fossil raw materials.

Demolition of a dilapidated bridge with high explosive charges. Such work is the art of foreseeing consequences.

This is how six tons of ammonal explode.

Ammonium nitrate, which serves as the basis of explosive composites, is literally produced from air and water according to the Haber method (the same Fritz Haber, who is known as the creator of chemical weapons). Explosives based on ammonium nitrate (ammonites and ammonals) revolutionized industrial explosives. They were not only very powerful, but also extremely cheap.

Thus, the mining and construction industries received cheap explosives, which, if necessary, can be successfully used in military affairs.

In the middle of the 20th century, composites of ammonium nitrate and diesel fuel became widespread in the United States, and then water-filled mixtures were obtained that are well suited for explosions in deep vertical wells. Currently, the list of individual and composite explosives used in the world includes hundreds of items.

So, let's sum up a brief and, perhaps, disappointing for someone, the result of our acquaintance with explosives. We got acquainted with the terminology of the explosive business, learned what explosives are and where they are used, and remembered a little history. Yes, we have not improved our education in the least in terms of the creation of explosives and explosive devices. And this, I tell you, is for the best. Be happy at the slightest opportunity.

By the hand of a child

Military engineer John Newton.

A striking example of work that would have been impossible without explosives is the destruction of the rocky reef Flood Rock in Hell's Gate - a narrow section of the East River near New York.

136 tons of explosives were used to produce this explosion. On an area of ​​38,220 square meters, 6.5 kilometers of galleries were laid, in which 13,280 charges were placed (an average of 11 kilograms of explosives per charge). The work was carried out under the supervision of a veteran civil war John Newton.

On October 10, 1885, at 11:13 am, Newton's twelve-year-old daughter applied electric current to the detonators. Water rose in a boiling mass over an area of ​​100,000 square meters, three consecutive tremors were noted within 45 seconds. The noise from the explosion lasted about a minute and was heard at a distance of fifteen kilometers. Thanks to this explosion, the route to New York from the Atlantic Ocean was reduced by more than twelve hours.

For most of history, man has used all kinds of edged weapons to destroy his own kind, ranging from a simple stone ax to very advanced and difficult to manufacture metal tools. Approximately in the XI-XII century, guns began to be used in Europe, and thus mankind became acquainted with the most important explosive - black powder.

This was the turning point in military history, although it took about another eight centuries for firearms to completely displace sharpened steel from the battlefields. In parallel with the progress of guns and mortars, explosives developed - and not only gunpowder, but also all kinds of compounds for equipping artillery shells or making land mines. The development of new explosives and explosive devices is actively continuing today.

Dozens of explosives are known today. In addition to military needs, explosives are actively used in mining, in the construction of roads and tunnels. However, before talking about the main groups of explosives, one should mention in more detail the processes occurring during an explosion and understand the principle of operation of explosives (HEs).

Explosives: what is it?

Explosives are a large group of chemical compounds or mixtures that, under the influence of external factors, are capable of a rapid, self-sustaining and uncontrolled reaction with the release of a large amount of energy. Simply put, a chemical explosion is the process of converting the energy of molecular bonds into thermal energy. Usually its result is a large amount of hot gases, which perform mechanical work (crushing, destruction, movement, etc.).

The classification of explosives is quite complex and confusing. Explosives include substances that decompose not only in the process of explosion (detonation), but also slow or rapid combustion. TO last group include gunpowder and various types of pyrotechnic mixtures.

In general, the concepts of "detonation" and "deflagration" (combustion) are key to understanding the processes of a chemical explosion.

Detonation is the rapid (supersonic) propagation of a compression front with an accompanying exothermic reaction in the explosive. In this case, chemical transformations proceed so rapidly and such an amount of thermal energy and gaseous products are released that a shock wave is formed in the substance. Detonation is the process of the most rapid, one might say, avalanche-like involvement of a substance in a chemical explosion reaction.

Deflagration, or combustion, is a type of redox chemical reaction during which its front moves in a substance due to normal heat transfer. Such reactions are well known to all and are often encountered in everyday life.

It is curious that the energy released during the explosion is not so great. For example, during the detonation of 1 kg of TNT, it is released several times less than during the combustion of 1 kg of coal. However, during an explosion, this happens millions of times faster, all the energy is released almost instantly.

It should be noted that the detonation propagation velocity is the most important characteristic of explosives. The higher it is, the more effective the explosive charge.

To start the process of a chemical explosion, it is necessary to influence an external factor, it can be of several types:

• mechanical (prick, impact, friction);
• chemical (the reaction of a substance with an explosive charge);
• external detonation (explosion in the immediate vicinity of explosives);
• thermal (flame, heating, spark).

It should be noted that different types Explosives have different sensitivity to external influences.

Some of them (for example, black powder) respond well to thermal effects, but practically do not respond to mechanical and chemical ones. And to undermine TNT, only a detonation effect is needed. Explosive mercury reacts violently to any external stimulus, and there are some explosives that detonate without any external influence at all. The practical use of such "explosive" explosives is simply impossible.

The main properties of explosives

The main ones are:

• the temperature of the explosion products;
• heat of explosion;
• detonation speed;
• brisance;
• explosiveness.

The last two points should be dealt with separately. The brisance of an explosive is its ability to destroy the environment adjacent to it (rock, metal, wood). This characteristic largely depends on the physical state in which the explosive is located (degree of grinding, density, uniformity). Brisance directly depends on the detonation speed of the explosive - the higher it is, the better the explosive can crush and destroy surrounding objects.

High explosives are commonly used to load artillery shells, aerial bombs, mines, torpedoes, grenades, and other munitions. This type of explosive is less sensitive to external factors to undermine such an explosive charge, an external detonation is required. Depending on their destructive power, high explosives are divided into:

• Increased power: hexogen, tetryl, oxygen;
• Medium power: TNT, melinite, plastid;
• Reduced power: Explosives based on ammonium nitrate.

The higher the explosive blast, the better it will destroy the body of a bomb or projectile, give the fragments more energy and create a more powerful shock wave.

An equally important property of explosives is their explosiveness. This is the most general characteristic of any explosive, it shows how destructive this or that explosive is. Explosiveness directly depends on the amount of gases that are formed during the explosion. It should be noted that brisance and explosiveness, as a rule, are not related to each other.

Explosiveness and brisance determine what we call the power or force of the explosion. However, for various purposes, it is necessary to select the appropriate types of explosives. Brisance is very important for shells, mines and air bombs, but for mining, explosives with a significant level of explosiveness are more suitable. In practice, the selection of explosives is much more complicated, and in order to choose the right explosive, all its characteristics should be taken into account.

There is a generally accepted way to determine the power of various explosives. This is the so-called TNT equivalent, when the power of TNT is conventionally taken as a unit. Using this method, it can be calculated that the power of 125 grams of TNT is equal to 100 grams of RDX and 150 grams of ammonite.

Another important characteristic of explosives is their sensitivity. It is determined by the probability of an explosive explosion under the influence of one or another factor. The safety of production and storage of explosives depends on this parameter.

To better show how important this characteristic of an explosive is, it can be said that the Americans have developed a special standard (STANAG 4439) for the sensitivity of explosives. And they had to do this not because of a good life, but after a series of severe accidents: 33 people were killed in an explosion at the Bien Ho American Air Force Base in Vietnam, about 80 aircraft were damaged as a result of explosions on the Forrestal aircraft carrier, as well as after the detonation of air missiles on the aircraft carrier "Oriskany" (1966). So not just powerful explosives are good, but detonating at exactly the right moment - and never again.

All modern explosives are either chemical compounds or mechanical mixtures. The first group includes hexogen, trotyl, nitroglycerin, picric acid. Chemical explosives are usually obtained by nitration of various types of hydrocarbons, which leads to the introduction of nitrogen and oxygen into their molecules. The second group includes ammonium nitrate explosives. Explosives of this type usually contain substances rich in oxygen and carbon. To increase the explosion temperature, metal powders are often added to the mixture: aluminum, beryllium, magnesium.

In addition to all the above properties, any explosive must be chemically resistant and suitable for long-term storage. In the 80s of the last century, the Chinese managed to synthesize the most powerful explosive - tricyclic urea. Its power exceeded TNT twenty times. The problem was that within a few days after being made, the substance decomposed and turned into a slime unsuitable for further use.

Classification of explosives

According to their explosive properties, explosives are divided into:

1. Initiators. They are used to detonate (detonate) other explosives. The main differences of this group of explosives are high sensitivity to initiating factors and high detonation velocity. This group includes: mercury fulminate, diazodinitrophenol, lead trinitroresorcinate and others. As a rule, these compounds are used in igniter caps, ignition tubes, detonator caps, squibs, self-liquidators;
2. High explosives. This type of explosive has a significant level of brisance and is used as the main charge for the vast majority of ammunition. These powerful explosives differ in their chemical composition (N-nitramines, nitrates, other nitro compounds). Sometimes they are used in the form of various mixtures. High explosives are also actively used in mining, tunneling, and other engineering work;
3. Throwable explosives. They are a source of energy for throwing shells, mines, bullets, grenades, as well as for the movement of rockets. This class of explosives includes gunpowder and various types of rocket fuel;
4. Pyrotechnic compositions. Used to equip special ammunition. When burned, they produce a specific effect: lighting, signal, incendiary.

Explosives are also divided according to their physical state into:

1. Liquid. For example, nitroglycol, nitroglycerin, ethyl nitrate. There are also various liquid mixtures of explosives (panclastite, Sprengel explosives);
2. gaseous;
3. Gel-like. If you dissolve nitrocellulose in nitroglycerin, you get the so-called explosive jelly. It is a highly unstable but rather powerful explosive gel-like substance. It was loved to be used by Russian revolutionary terrorists at the end of the 19th century;
4. Suspensions. Quite an extensive group of explosives, which are currently used for industrial purposes. There are various types of explosive suspensions in which the explosive or oxidizing agent is a liquid medium;
5. Emulsion explosives. A very popular type of VV these days. Often used in construction or mining operations;
6. Solid. The most common group of V.V. It includes almost all explosives used in military affairs. They can be monolithic (TNT), granular or powdered (RDX);
7. Plastic. This group of explosives has plasticity. Such explosives are more expensive than conventional ones, so they are rarely used to equip ammunition. A typical representative of this group is the plastid (or plastitis). It is often used during sabotage to undermine structures. According to its composition, plastids are a mixture of hexogen and some kind of plasticizer;
8. Elastic.

A bit of VV history

The first explosive that was invented by mankind was black powder. It is believed that it was invented in China as early as the 7th century AD. However, reliable evidence for this has not yet been found. In general, many myths and obviously fantastic stories have been created around gunpowder and the first attempts to use it.

There are ancient Chinese texts that describe mixtures similar in composition to black smoke powder. They were used as medicines, as well as for pyrotechnic shows. In addition, there are numerous sources claiming that in the following centuries, the Chinese actively used gunpowder to produce rockets, mines, grenades, and even flamethrowers. True, illustrations of some types of these ancient firearms cast doubt on the possibility of its practical application.

Even before gunpowder, “Greek fire” began to be used in Europe - a combustible explosive, the recipe of which, unfortunately, has not survived to this day. "Greek fire" was a flammable mixture, which not only was not extinguished by water, but even became even more flammable in contact with it. This explosive was invented by the Byzantines, they actively used the "Greek fire" both on land and in sea battles, and kept its recipe in the strictest confidence. Modern experts believe that this mixture included oil, tar, sulfur and quicklime.

Gunpowder first appeared in Europe around the middle of the 13th century, and it is still unknown how exactly it got to the continent. Among the European inventors of gunpowder, the names of the monk Berthold Schwartz and the English scientist Roger Bacon are often mentioned, although there is no consensus among historians. According to one version, gunpowder, invented in China, came to Europe through India and the Middle East. One way or another, already in the 13th century, Europeans knew about gunpowder and even tried to use this crystalline explosive for mines and primitive firearms.

For many centuries, gunpowder remained the only type of explosive that people knew and used. Only at the turn of the XVIII-XIX centuries, thanks to the development of chemistry and other natural sciences, the development of explosives reached new heights.

At the end of the 18th century, thanks to the French chemists Lavoisier and Berthollet, the so-called chlorate powder appeared. At the same time, “explosive silver” was invented, as well as picric acid, which in the future began to be used to equip artillery shells.

In 1799, the English chemist Howard discovered "explosive mercury", which is still used in capsules as an initiating explosive. At the beginning of the 19th century, pyroxylin was obtained - an explosive that could not only equip shells, but also make smokeless powder from it. dynamite. This is a powerful explosive, but it is highly sensitive. During the First World War, they tried to equip shells with dynamite, but this idea was quickly abandoned. Dynamite was used in mining for a long time, but these explosives have not been produced for a long time.

In 1863, German scientists discovered TNT, and in 1891, industrial production of this explosive began in Germany. In 1897, the German chemist Lenze synthesized hexogen, one of the most powerful and common explosives today.

The development of new explosives and explosive devices continued throughout the past century, and research in this direction is still going on today.

The Pentagon received a new explosive based on hydrazine, which was allegedly 20 times more powerful than TNT. However, this explosive also had one tangible minus - the absolutely vile smell of an abandoned station toilet. The test showed that the power of the new substance exceeds TNT by only 2-3 times, and they decided to refuse to use it. After that, EXCOA proposed another way to use the explosive: to make trenches with it.

The substance was poured on the ground in a thin stream, and then exploded. Thus, in a matter of seconds, it was possible to get a trench of a full profile without any extra effort. Several sets of explosives were sent to Vietnam for combat testing. The end of this story was funny: the trenches obtained with the help of the explosion had such a disgusting smell that the soldiers refused to be in them.

In the late 80s, the Americans developed a new explosive - CL-20. According to some media reports, its power is almost twenty times higher than TNT. However, due to its high price ($ 1,300 per 1 kg), large-scale production of the new explosive was never launched.

Terminology

The complexity and diversity of the chemistry and technology of explosives, political and military contradictions in the world, the desire to classify any information in this area have led to unstable and diverse formulations of terms.

Industrial Application

Explosives are also widely used in industry for the production of various blasting operations. The annual consumption of explosives in countries with developed industrial production, even in peacetime, is hundreds of thousands of tons. In wartime, the consumption of explosives increases sharply. So, during the 1st World War in the warring countries it amounted to about 5 million tons, and in the 2nd World War it exceeded 10 million tons. The annual use of explosives in the United States in the 1990s was about 2 million tons.

• throwing
  Throwing explosives (gunpowder and rocket propellants) serve as sources of energy for throwing bodies (shells, mines, bullets, etc.) or propelling rockets. Their distinctive feature is the ability to explosive transformation in the form of rapid combustion, but without detonation.
• pyrotechnic
  Pyrotechnic compositions are used to obtain pyrotechnic effects (light, smoke, incendiary, sound, etc.). The main type of explosive transformations of pyrotechnic compositions is combustion.

Throwing explosives (gunpowder) are mainly used as propellant charges for various types of weapons and are intended to give a projectile (torpedo, bullet, etc.) a certain initial speed. Their predominant type of chemical transformation is rapid combustion caused by a beam of fire from the means of ignition. Gunpowder is divided into two groups:

a) smoky

b) smokeless.

Representatives of the first group can serve as black powder, which is a mixture of saltpeter, sulfur and coal, such as artillery and gunpowder, consisting of 75% potassium nitrate, 10% sulfur and 15% coal. The flash point of black powder is 290 - 310 ° C.

The second group includes pyroxylin, nitroglycerin, diglycol and other gunpowders. The flash point of smokeless powders is 180 - 210 ° C.

Pyrotechnic compositions (incendiary, lighting, signal and tracer) used to equip special ammunition are mechanical mixtures of oxidizers and combustible substances. Under normal conditions of use, when burned, they give the corresponding pyrotechnic effect (incendiary, lighting, etc.). Many of these compounds also have explosive properties and under certain conditions can detonate.

According to the method of preparation of charges

• pressed
• cast (explosive alloys)
• patronized

By areas of application

• military
• industrial

• for mining (mining, production of building materials, stripping)
  Industrial explosives for mining according to the conditions of safe use are divided into

• non-safety
• safety

• for construction (dams, canals, pits, road cuts and embankments)
• for seismic exploration
• for the destruction of building structures
• for material processing (explosion welding, explosion hardening, explosion cutting)

• special purpose (for example, means of undocking spacecraft)
• anti-social use (terrorism, hooliganism), often using low-quality substances and artisanal mixtures.
• experimental.

According to the degree of danger

There are various systems for classifying explosives according to the degree of danger. The most famous:

• Globally Harmonized System of Classification and Labeling of Chemicals

• Classification according to the degree of danger in mining;

By itself, the energy of the explosive is small. An explosion of 1 kg of TNT releases 6-8 times less energy than the combustion of 1 kg of coal, but this energy is released during an explosion tens of millions of times faster than during conventional combustion processes. In addition, coal does not contain an oxidizing agent.

see also

Literature

1. Soviet military encyclopedia. M., 1978.
2. Pozdnyakov Z. G., Rossi B. D. Handbook of Industrial Explosives and Explosives. - M.: "Nedra", 1977. - 253 p.
3. Fedoroff, Basil T. et al Enciclopedia of Explosives and Related Items, vol.1-7. - Dover, New Jersey: Picatinny Arsenal, 1960-1975.

Links

• // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional). - St. Petersburg. , 1890-1907.

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EXPLOSIVES, a substance that reacts quickly and sharply to certain conditions, with the release of heat, light, sound and shock waves. Chemical explosives are for the most part compounds with a high content… Scientific and technical encyclopedic dictionary