Initiating explosives. Introduction. See what “initiating explosives” are in other dictionaries

INITIATING EXPLOSIVES (primary explosives), easily explode under the influence of a simple initial impulse (impact, beam of fire) with the release of energy sufficient for ignition or detonation high explosives(secondary explosives). I.v. c., used for ignition, as a rule, have a high burning rate; characteristic feature of I. v. used to initiate detonation - an easy transition of combustion in those conditions (atm., weak shell or its absence, small charges), in which such a transition does not occur for secondary explosives. This difference is due to the fact that already at atm. chemical pressure transformation of I. into. v., compared to other explosives, is completed very quickly with the release of max. amount of heat and the formation of gases with high temperature, which leads to a rapid rise in pressure and the formation of detonation. waves. Requirements for IV. v.: high initiating ability, ensuring trouble-free initiation of an explosion in a secondary explosive charge with small quantities of explosives. V.; safety in handling and use; good flowability and compressibility, necessary for precise dosing (by volume) of small portions of IV. V. and preventing its spillage from finished products; high chemical and physical durability; compatibility with secondary explosives and structures. materials; moisture resistance. I.v. V. can be individual connections. or mixtures. Individual I.v. V. usually contain in a metal molecule, which acts as a catalyst during combustion, or a group of atoms, during decomposition a large amount of heat is released. The most important representatives of individual I. v. c.: fulminates of heavy metals, e.g. mercury fulminate Hg(ONC) 2, salts and other derivatives of hydronitric acid, for example, lead azide Pb(N 3) 2, cyanurtriazide C 3 N 12; heavy metal salts of nitrophenols, e.g. di- and trinitroresorcinate Pb, picrate Pb; certain tetrazene derivatives, for example. conn. Forms I, called in technology; tetrazole derivatives, e.g. II; metal acetylenides, e.g. Ag 2 C 2; certain diazo compounds, for example. III and IV; org. peroxides, eg. V; complex connections perchlorates and transition metal chlorates with tetrazole derivatives, e.g. VI, etc.

In technology, ch. arr. tatrazene, fulminate, azide and lead trinitroresorcinate. Mixed I.v. V. consist of several components, at least one of which is an oxidizer, and the others are flammable; in addition, they usually contain additional components that increase the sensitivity of the composition to the initial impulse, improve compressibility and flowability, increase moisture resistance, etc. The content of the components is determined by the requirements for IV. V. So, mixed I.v. V. for impact igniter capsules contains 16-28% mercury fulminate, 36-55% KClO 3 and 28-37% Sb 2 S 3. Ability I.v. c., taken in a small amount, cause the detonation of other explosives. Their initiating ability is called. It is characterized by a maximum initiating charge, i.e., a minimum number of i.v. c., capable of causing detonation of a secondary explosive under certain conditions. For tetryl, under certain conditions, the maximum initiating charge of lead azide is 0.025 g, mercury fulminate - 0.29 g, for TNT - respectively. 0.09 and 0.36 g. Initiating ability IV. V. with the same secondary charge and use under the same conditions depends on its density, degree of purity, crystal size, equipment conditions, charge and product design, etc. I.V. V. used in military equipment and explosives in the form of small (fractions of a gram) charges placed in special. designs - so-called. detonator caps and igniter caps, which are designed to initiate the detonation of secondary explosives or to ignite gunpowder and pyrotechnics. compositions. In detonator capsules, as a rule, individual compounds are used, and in igniter capsules - decomposition. mixtures, one of the components of which is I. v. V. Production of I.V. V. and handling them require special precautions due to the high risk of explosion. They can only be transported in the form of products. A. E. Vogelsang.

Chemical encyclopedia. - M.: Soviet Encyclopedia. Ed. I. L. Knunyants. 1988 .

See what "INITIATING EXPLOSIVES" are in other dictionaries:

Initiating explosives are individual substances or mixtures that easily explode under the influence of a simple initial impulse (impact, friction, beam of fire) with the release of energy sufficient to ignite or detonate the high explosives ... ... Wikipedia

Primary explosives (a. explosive initiators; n. Initialsprengstoffe; f. explosifs d amorзage; i. explosivos iniciadores), are capable of easily detonating from simple types of initial impulse (external influence) of flame, impact, ... ... Geological encyclopedia

Explosives that easily detonate from minor thermal or mechanical effects; used to initiate the detonation of high explosives. Used in detonator capsules, etc... Big Encyclopedic Dictionary

See Explosives. Samoilov K.I. Marine dictionary. M. L.: State Naval Publishing House of the NKVMF of the USSR, 1941 ... Marine Dictionary

Explosives that easily detonate from minor thermal or mechanical effects; used to initiate the detonation of high explosives. Used in detonator capsules, etc. * * * INITIATING EXPLOSIVES... ... encyclopedic Dictionary

INITIATING EXPLOSIVES- Individual substances or mixtures that readily explode under the influence of a simple initial impulse (impact, friction, beam of fire) with the release of energy sufficient to ignite or detonate high explosives. Characteristic feature... ... Comprehensive provision of security and anti-terrorist protection of buildings and structures- (BB), individual in va or mixtures, capable of under the influence of k. l. ext. influence (heating, impact, friction, explosion of another explosive, etc.) to rapid self-propagating chemical. rations with the release of a large amount of energy and the formation of gases (see... ... Chemical encyclopedia

- (VV) chem. compounds or mixtures in, capable of rapid chemical a reaction accompanied by the release of a large amount of heat and the formation of gases. The reaction propagates throughout the explosive charge in combustion or detonation mode. The explosives include Ch. arr.... ... Big Encyclopedic Polytechnic Dictionary

The invention relates to initiating explosives, sensitive to low-power pulsed laser radiation, and can be used in initiation means as a generator of flat, cylindrical, spherical and complex shapes of shock waves, as well as in optical systems for initiating explosive charges. An initiating explosive composition is proposed, sensitive to low-temperature laser radiation, containing 5-hydrazinotetrazolemercury (II) perchlorate, polymethylvinyltetrazole and detonation synthesis nanodiamonds. The invention is aimed at reducing the initiation threshold of the explosive composition while maintaining high adhesion to the surface of the explosive and safety in handling. 1 table

Field of technology

The invention relates to initiating explosives excited by low-power pulsed laser radiation and can be used in initiation means as a generator of flat, cylindrical, spherical and complex shock waves, as well as in optical systems for initiating explosive charges.

Prior Art

Laser initiation is a relatively new method of detonating explosives, characterized by increased safety. With laser initiation, a high level of isolation of the light detonator from a false pulse is ensured, since in the optical range there are no random sources with a power sufficient to detonate the detonator [Ilyushin M.A., Tselinsky I.V. Initiating explosives. Ross. Chem. Journal - 1997, v. 41, no. 4, pp. 3-13].

Photosensitive explosives have found application in fiber-optic detonator capsules operating under the influence of pulsed laser radiation.

Laser initiation can be successfully used in many explosive technologies that require an individual approach when developing blasting systems:

Explosive welding, stamping, hardening, compacting, synthesis of new materials can be carried out with fiber-optic initiation of one or several light detonators when detonating film charges of photosensitive explosives with a direct beam of a pulsed laser;

Mining blasting operations, both overburden and in mines hazardous due to gases and dust, require simultaneous or short-delay initiation of a large number of light detonators through fiber-optic communication lines;

Automated technologies with pulse-periodic supply of material on which a film charge of a photosensitive explosive is applied or an explosive charge initiated from a light detonator is placed, can be carried out by transmitting a laser pulse directly through air or in a vacuum;

Single-action explosive technology, used, for example, in pyro-automation of spaceships, requires several dozen fiber-optic channels that simultaneously transmit a signal to light detonators from an onboard pulsed laser of limited power;

When perforating deep wells, heat-resistant fiber-optic light detonators with high susceptibility to a laser pulse should be used, ensuring reliable initiation of up to 100 shaped charges of high explosives;

With low-hazard technology for producing nanodiamonds by detonation synthesis;

When carrying out blasting operations in conditions of high levels of electromagnetic interference, special shielded fiber-optic light detonators are required.

One of the main elements of the laser initiation circuit is photosensitive, energy-intensive substances. Depending on the solution to specific problems, inorganic azides and energy-intensive metal complexes with different initiation thresholds by a laser monopulse (pulse time - 10 -8 s) or a single pulse (pulse time up to ˜10 -3 s) were proposed as photosensitive explosives for light detonators.

And one of the most effective initiating explosives (IEV) is 5-hydrazinotetrazolemercury (II) perchlorate, which is used individually and in the form of compositions mixed with optically transparent polymers in optical initiation systems as a highly photosensitive, energy-intensive substance that has a low sensitivity threshold to pulsed laser radiation in the visible and near-IR regions of the spectrum (wavelength 1.06 μm) [Chernay A.V., Zhitnik N.E., Ilyushin M.A., Sobolev V.V., Fomichev V.V. Patent of Ukraine No. 17521Ayu 1997; Ilyushin M.A., Tselinsky I.V. Energy-intensive matellocomplexes in initiation means // Ross. Chem. Journal - 2001. No. 1, pp. 72-78].

5-hydrazinotetrazolemercury (II) perchlorate (ClO 4) 2 has the following characteristics: molecular weight 499.577; density of single crystals ˜3.45 g/cm 3 ; flash point (5 second delay) about 186°C; activation energy of thermal decomposition ˜90.2 kJ/mol; Impact sensitivity (Wöhler impact driver) (lower limit/upper limit) 60/125 mm; sensitivity to the fire ray of the fire cord (100% operation/100% failure) 60/150 mm; detonation speed at a density of 3.4 g/cm 3 ˜6 km/s (calculation); the minimum charge of hexogen in detonator capsule No. 8 is ˜0.015 g. 5-hydrazinotetrazolemercury (II) perchlorate is non-hygroscopic, insoluble in water, alcohol, acetone, aliphatic, chlorinated and aromatic hydrocarbons, soluble in dimethyl sulfoxide, oxidized with an alkaline solution of KMnO 4 to non-explosive compounds . The introduction of polymers into 5-hydrazinotetrazolemercury (II) perchlorate sharply reduces the sensitivity of the compositions to mechanical stress, which makes them relatively safe during transportation, storage and use [Scientific and technical report on the research work “Light-sensitive materials for light products used in downhole equipment” /man. Tselinsky I.V., St. Petersburg. SPbGTI (TU), 2002. p.14; Ilyushin M.A., Tselinsky I.V., Chernay A.V. Photosensitive explosives and compositions and their initiation by laser monopulse. // Ross. Chem. Journal - 1997, No. 4, pp. 81-88].

5-hydrazinotetrazolemercury (II) perchlorate has the gross formula CH 4 N 6 O 8 Cl 2 Hg and the structural formula

The closest analogue is the use of 5-hydrazinotetrazolemercury (II) perchlorate in a photosensitive composition containing ˜90% of this compound and ˜10% of an optically transparent polymer (composition VS-2) [RF Patent Application 2002113197/15. Method for obtaining 5-hydrazinotetrazolemercury (II) perchlorate dated May 20, 2002, Ilyushin M.A., Tselinsky I.V. Decision to issue a patent dated September 26, 2003].

The disadvantage of the prototype is that the minimum initiation energy (E cr) of such a composition is a fairly large value of 310 μJ.

The objective of the present invention is to obtain a technical result, which is expressed in reducing the threshold for initiation of a composition with 5-hydrazinotetrazolemercury (II) perchlorate by a monopulse of a neodymium laser (wavelength 1.06 μm).

Disclosure of the Invention

The basis of this invention is the task of creating a composite material that would significantly reduce the initiation threshold while maintaining all other positive characteristics of the composition (high adhesion to the explosive surface, high safety of handling the composition, convenience and simplicity of its application, the same initiation delay time and etc.).

The solution to the problem is that an initiating composition is proposed containing 5-hydrazinotetrazolemercury (II) perchlorate and a polymer - polymethylvinitetrazole, which, according to the invention, additionally includes nanodiamonds of detonation synthesis in the following ratio of components, wt.%:

5-hydrazinotetrazolemercury perchlorate (II) - 85.7-90.0;

polymer - polymethylvinitetrazole - 9.5-10.0;

nanodiamonds of detonation synthesis - 0.1-5.0.

Best Mode for Carrying Out the Invention

The proposed composition, containing nanodiamonds in an amount of 0.1-5.0 wt.% of the total mass of the composition, provides a simultaneous increase in sensitivity to the action of a laser pulse by 1.5-1.7 times and high adhesion to the contact surface due to enhanced adhesive properties thermoplastic (polymethylvinyltetrazole).

Cluster nanodiamonds used in this method are particles that are close to spherical or oval in shape and do not have sharp edges (non-abrasive). Such diamonds form sedimentation and coagulation stable systems in liquid media of various types.

Currently, the synthesis of UDD is carried out by detonating specially prepared charges from mixed compositions of TNT-RDX in explosion chambers filled with a non-oxidizing environment [V.Yu. Dolmatov. Ultrafine diamonds of detonation synthesis. St. Petersburg, St. Petersburg State Pedagogical Institute Publishing House, 2003, 344 pp.]. The resulting diamond charge (a mixture of diamonds with non-diamond forms of carbon) is subjected to chemical purification, the most advanced of which is the treatment of the diamond charge in nitric acid at high temperatures and pressure, followed by washing [Russian Patent No. 2109683, class. С01В 31/06, publ. 03/05/96 Method of isolating synthetic ultrafine diamonds. V.Yu. Dolmatov, V.G. Sushchev, V.A. Marchukov].

From a morphological point of view, UDD is a powder with a specific surface area of ​​150-450 m 2 /g and a pore volume of 0.3-1.5 cm 3 /g (in a dry state). In suspension, UDD aggregates can have a size of up to 50 nm (0.05 μm) subject to special treatment. The average size of individual diamond crystals is 4-6 nm (0.004-0.006 microns) [Dolmatov V.Yu. Experience and prospects for the unconventional use of ultrafine explosive synthesis diamonds. Superhard materials, 1998, No. 4, pp. 77-81].

UDDs have a classical cubic (diamond) crystal lattice with large surface defects, which determines the significant surface energy of such crystals. The excess surface energy of UDD particles is compensated by the formation of numerous surface groups, forming on the surface a shell (“fringe”) of hydroxyl, carbonyl, carboxyl, nitrile, quinoid and other groups chemically bound to the crystal, representing various stable combinations of carbon with other elements of the explosives used substances - oxygen, nitrogen and hydrogen [Dolmatov V.Yu. et al., ZHPH, 1993, vol. 66, No. 8, p. 1882]. Under normal conditions, UDD microcrystallites cannot exist without such a shell; this is an integral part of cluster nanodiamonds, which largely determines their properties.

Thus, UDDs combine a paradoxical principle - a combination of one of the most inert and hard substances in nature - diamond (core) with a fairly chemically active shell in the form of various functional groups capable of participating in various chemical reactions. In addition, such diamond crystals, despite the compensation of part of the unpaired electrons due to the formation of surface functional groups, still have a fairly large excess of them on the surface, i.e. Each diamond crystal is, in fact, a multiple radical.

In percentage terms, the proportion of non-diamond carbon in high-quality UDD varies from 0.4 to 1.5 by weight of the substance. It is significant that the so-called non-diamond carbon in this case does not constitute a separate phase or individual particles and is not defined crystallographically as graphite or micrographite. Two forms of carbon - diamond and non-diamond - are differentiated by the electronic state of the atoms and chemical reactivity towards liquid-phase oxidizers [Dolmatov V.Yu., Gubarevich T.M. ZHPH, 1992, vol. 65, No. 11, p. 2512]. The task of peripheral non-diamond structures is to ensure maximum exposure of the particle with the matrix material - polymethylvinyltetrazole at the moment of its polymerization in the form of a film on the contact surface. Diamond tetrahedral sp 3 -carbon is chemically and sorption inactive, non-diamond electronic configurations of carbon (sp 2 and sp) are much more labile and, together with oxygen and hydrogen heteroatoms, form an adsorption-active “coat” on top of the diamond core, associated with the polymerizing polymer in a fairly stable manner chemical bonds.

The introduction of nanodiamonds into the polymer in an amount of 0.1-5.0% contributes to a significant increase in the cohesive (1.5-3.0 times) and adhesive properties (1.7-2.5 times) of the vulcanized polymer, which also occurs in case of using polymethylvinyltetrazole. Film with nanodiamonds has a very high resistance to thermal aging and can remain unchanged for at least three years. Such a film is characterized by an increase in elastic-strength properties, which can significantly increase the range of its use.

It is known that finely dispersed soot is in some cases successfully used to increase the susceptibility of energetic materials to a single pulse of infrared lasers. However, the effects of other allotropic forms of carbon on laser initiation thresholds of energetic materials have not been studied.

For comparison, the table shows the influence of ultrafine soot (particle size ˜1 μm) and nanodiamonds on the initiation threshold of the photosensitive composition BC-2. The initiation of explosive compositions was carried out under the influence of a monopulse of a neodymium laser (wavelength 1.06 μm, pulse time τ q = 30 ns, diaphragm diameter 0.86 mm, total pulse energy E = 1.5 J). The samples under study were copper caps with a diameter of 5 mm and a height of 2 mm, filled with the BC-2 composition.

Table
№	Sample composition, wt.%	Minimum initiation energy, E cr, µJ	Initiation Result
1	Composition of VS-2: (5-hydrazinotetrazolemercury (II) perchlorate - 90 Polymer - polymethylvinyltetrazole - 10)	310	detonation
2	Soot-1	2000	detonation
3	5-hydrazinotetrazolemercury perchlorate (II) - 89.9 Polymer - polymethylvinyltetrazole - 10.0 Nanodiamonds - 0.1	300	detonation
4	5-hydrazinotetrazolemercury perchlorate (II) - 89.6 Polymer - polymethylvinyltetrazole - 9.9 Nanodiamonds - 0.5	260	detonation
5	5-hydrazinotetrazolemercury perchlorate (II) - 89.10 Polymer - polymethylvinyltetrazole - 9.9 Nanodiamonds - 1.0	200	detonation
6	5-hydrazinotetrazolemercury perchlorate (II) - 88.2 Polymer - polymethylvinyltetrazole - 9.8 Nanodiamonds - 2.0	180	detonation
7	5-hydrazinotetrazolemercury perchlorate (II) - 87.4 Polymer - polymethylvinyltetrazole - 9.7 Nanodiamonds - 2.9	190	detonation
8	5-hydrazinotetrazolemercury perchlorate (II) - 86.5 Polymer - polymethylvinyltetrazole - 9.6 Nanodiamonds - 3.9	240	detonation
9	5-hydrazinotetrazolemercury perchlorate (II) - 86.1 Polymer - polymethylvinyltetrazole - 9.6 Nanodiamonds - 4.3	285	detonation
10	5-hydrazinotetrazolemercury perchlorate (II) - 85.7 Polymer - polymethylvinyltetrazole - 9.5 Nanodiamonds - 4.8	300	detonation
11	5-hydrazinotetrazolemercury perchlorate (II) - 85.4 Polymer - polymethylvinyltetrazole - 9.6 Nanodiamonds - 5.0	310	detonation

The data in the table allows us to conclude that finely dispersed soot significantly increases the threshold for initiation of the BC-2 composition by a laser monopulse. This result can be explained by the dissipation of laser energy absorbed by finely dispersed soot from the surface of a sample of the BC-2 composition, which leads to a deterioration in the conditions for the formation of the initiation source inside the composition layer with an increase in the critical ignition energy.

The effect of nanodiamonds on the BC-2 composition differs from the effect of ultrafine soot on it. Introduction of nanodiamonds up to 5.0% wt. reduces the threshold for initiation of the BC-2 composition by a monopulse of a neo-Dom laser. This effect can be explained as a result of an increase in volumetric illumination inside the charge and an improvement in the conditions for the formation of the initiation site due to the introduction of nanodiamonds with a significantly higher refractive index of light than the initial composition. A further increase in the amount of nanodiamonds in the composition leads to a decrease in its susceptibility to laser radiation. The increase in the initiation threshold of the BC-2 composition, containing more than 5 wt.% nanodiamonds, is obviously a consequence of the negative effect of diluting the photosensitive composition with an inert additive.

The initiation delay time of the BC-2 composition with the introduction of nanodiamonds up to 5% wt. does not change and is 11-12 μs.

For a better understanding of the present invention, specific examples of its implementation are provided.

To 90 mg of 5-hydrazinotetrazolemercury (II) perchlorate was added 100 mg of a 10% solution of the polymer - polymethylvinyltetrazole in chloroform. With stirring, 0.5 ml of chloroform was added dropwise to the resulting suspension 8 and 1.5 mg of nanodiamonds were sprinkled. The resulting homogeneous paste was introduced into a metal cap with a diameter of 5 mm and a height of 2 mm in several stages. After the solvent evaporated, the composition with nanodiamonds completely filled the cap. The charge was dried at 40°C.

The resulting photosensitive composition has the following ratio of components: explosives: polymer: nanodiamonds = 90:10:1.5, i.e. contains ˜1.4 wt.% nanodiamonds.

Testing of the resulting explosive composition to a laser monopulse showed that the minimum initiation energy is 192 μJ.

Other examples (see Table, examples 3-10) were carried out in a similar way, with the difference that various weighed amounts of nanodiamonds were added to the prepared composition, corresponding to the content of the latter from 0.1 to 5.0 wt.%. The results of determining the minimum initiation energy are also given in the Table.

Explosives. Classification and properties.

Explosives are chemical compounds or mixtures that, under the influence of certain external influences, are capable of rapid self-propagating chemical transformation with the formation of highly heated and high-pressure gases, which, expanding, produce mechanical work.

Such chemical transformations of explosives are usually called explosive transformations.

Explosive transformations, depending on the properties of the explosive and the type of impact on it, can occur in the form of explosion or combustion.

Explosion propagates through explosives with a high variable speed, measured in thousands of meters per second. The process of explosive transformation, caused by the origin of a shock wave along an explosive and occurring at a constant (for a given substance in a given state) supersonic speed, is called detonation.

Combustion- a process of explosive transformation caused by the transfer of energy from one layer of explosive to another through thermal conductivity and radiation of heat by gaseous products.

Excitation of explosive transformation of explosives is called initiation. To excite an explosive, it is necessary to provide it with a certain intensity of the required amount of energy (initial impulse), which can be transferred in one of the following ways:

Mechanical (impact; heat; friction);
-thermal (spark, flame, heating);

Electrical (heating, spark discharge);

Chemical (reactions with intense heat release);

Explosion of another explosive charge (explosion of a detonator capsule or a neighboring charge).
All explosives used in blasting operations and equipment

ammunition are divided into three main groups:

Initiating explosives;

High explosives;

Propellant explosives (powder).

Scheme 12. Classification of explosives (explosives) (option).

Initiating explosives are highly sensitive to external influences (impact, friction and fire). The explosion of relatively small quantities of initiating explosives in direct contact with high explosives causes detonation of the latter.

It is used exclusively for equipping initiation devices (detonator caps, igniter caps, etc.)

Mercury fulminate(mercury fulminate) - a fine-crystalline granular substance of white or gray color, poisonous, poorly soluble in water. It is very sensitive to impact, friction, and heat; when moistened, the explosive properties and susceptibility to the initial impulse decrease. It is used to equip an igniter primer (KB) and a detonator primer (CD) in copper or cupronickel sleeves.

Lead azide(lead nitrate) is a finely crystalline white substance, slightly soluble in water. Less sensitive to impact, friction, and fire than mercury fulminate. The initiating ability is higher than that of mercury fulminate. Used to equip CD.

Teneres(lead trinitroresorcinate, TNRS) is a finely crystalline, non-flowing, dark yellow substance. Slightly soluble in water. Impact sensitivity is lower than that of mercury fulminate and lead azide. Very sensitive to heat. TNRS does not interact with metals. Due to its low capacity, it is used with lead azide.

Capsule composition used to equip igniter primers. It is a mechanical mixture (mercury fulminate, potassium chlorate (Berthollet salt) and antimony trisulfide (antimonium)).

Under the influence of heat or impact of the explosive, the capsule composition ignites, producing a beam of fire that can ignite or cause detonation of the initiating explosive.

High explosives.

High explosives are more powerful and significantly less sensitive to various external influences than initiating explosives. Explode from an intermediate detonator (CD, explosion of another explosive). The relatively low sensitivity of high explosives to impact, friction and thermal effects ensures sufficient safety and ease of practical use. High explosives are used in their pure form in the form of alloys and admixtures with other explosives.

The impulse required to initiate an explosion is imparted to the charge of an industrial explosive as a result of the explosion of a small-sized charge of an initiating explosive placed in (CD), (ED) directly or through a more powerful intermediate detonator P≈200÷400 g or more to initiate low-sensitive (granular, cast, water-filled explosives). The detonation of initiating explosives is excited by a thermal pulse in the CD of the burning powder core of the OS, in the ED and electric ignition devices by a burning droplet of the igniter composition located on the incandescent bridge of the electric igniter, or by a flame of a retardant composition in the SC ED and delayed ED of the igniter.

In open-pit work and mines, the role of the initiating charge placed in the explosive charge is performed by the DS, the core of which is made of a powerful explosive, onto the end of which an intermediate detonator is tied. To initiate a blast explosion, it is necessary to use CD and ED.

Initiation means - a set of accessories for initiating industrial explosive charges.

Initiating explosives:

Primary initiating explosives are capable of exploding in charges of small weight and size (a fraction of a gram), and have a very high sensitivity to mechanical and thermal influences; the combustion of these explosives almost instantly turns into detonation.

Primary initiating explosives (mercury fulminate, lead azide, teneres)

Secondary initiating explosives - (tetryl, hexogen, PETN) are designed to increase the energy of the initial impulse imparted by the charge of the primary initiating explosive, and to detonate the charge of an industrial explosive. They are less sensitive to external influences, but have a higher detonation speed, heat of explosion and a higher initiating ability compared to the primary initiating explosive.

Characteristic feature initiating explosives (IEV) is that their combustion easily turns into detonation. IVVs also easily detonate under the influence of a simple initial impulse (a ray of fire, a puncture, an impact, etc.). It is these features that made it possible to use them for the manufacture of initiators. However, due to the high sensitivity of explosives to the initial impulse, special precautions should be taken during their production, as well as during their use. Currently, the most widely used explosives are mercury fulminate, lead azide and lead trinitroresorcinate (TNRS).

Mercury fulminate Hg (ONC) 2 is a white or gray crystalline powder with a bulk density of 1.22-1.25 g/cm 3 . The crystal density ranges from 4.30 to 4.42 g/cm 3 .

When ignited, mercury fulminate, loosely poured in small quantities (up to 1 g), produces a flash; When ignited in large quantities, an explosion occurs. If mercury fulminate is pressed under a pressure of 250-350 kgf/cm2, then when it ignites, an explosion always occurs.

Therefore, when producing electric detonators, mercury fulminate is placed in copper or paper sleeves.

Lead azide Pb(N 3) 2 is a fine-crystalline white powder with a density of 4.73 g/cm 3 .

Lead azide is less sensitive to mechanical effects (impact, friction, etc.) than mercury fulminate. Lead azide is also much more difficult to ignite from a ray of fire than mercury fulminate. This is its significant drawback: for trouble-free operation of detonators, it is necessary to cover the surface of lead azide with a layer of lead trinitroresorcinate.

In contrast to mercury fulminate, pressing leaves almost no change in the sensitivity of lead azide to the initial impulse.

Lead azide has a high initiating ability (about 10 times greater than mercury fulminate).

The heat of explosion of lead azide is 364 kcal/kg. The volume of explosion gases is 308 l/kg. The detonation speed of lead azide is 4.5-4.8 m/s.

Lead trinitroresorcinade (TNRS)

It is a golden-yellow crystal that darkens in air with a density of about 3.1 g/cm 3 . THPC is poorly soluble in water and organic solvents. TNPC is much more easily ignited by a fire beam than lead azide, but is significantly inferior to it in initiating ability. Therefore, TNRS is not used as an independent initiating explosive, but is used in electric detonators together with lead azide.

Initiating explosives- are called explosives capable of exploding in small quantities (fractions of a gram) under the influence of a weak external impulse (spark, friction, impact, etc.). Based on sensitivity, initiating explosives are divided into primary and secondary. The distinctive features of the primary ones are their high sensitivity to mechanical and thermal influences; the combustion of explosives almost instantly turns into detonation. The primary initiating explosives are mercury fulminate, lead azide, and TNPC. Primary initiating explosives initiate more powerful secondary initiating substances hexogen, PETN. Which cause an explosion of an industrial explosive charge. Intermediate detonators are made from charges of TNT or tetryl and hexogen weighing 200 or 800 grams. With a hole in the center for a detonating cord, or electric detonator.

For the manufacture of initiation means (SI) used in industry, very sensitive explosives are used.

Mercury fulminate- crystalline poisonous powder of white or gray color with an ignition temperature of 160˚C; in a dry powder state, an extremely sensitive explosive that explodes under the weakest mechanical stress. This is the most sensitive of all initiating explosives used. At a moisture content of 10%, mercury fulminate only burns and does not detonate; at a moisture content of 30%, it will not even ignite. Therefore, mercury fulminate is stored in containers with water. Pressed mercury fulminate acquires greater power and is less sensitive to external influences. Therefore, in the manufacture of detonators, primary charges of mercury fulminate are used in pressed form. In the presence of moisture, mercury fulminate reacts with copper, forming very sensitive copper fulminotes. In this regard, detonators in copper sleeves filled with mercury fulminate must be protected from moisture. Mercury fulminate reacts with aluminum, forming non-explosive compounds, which is why aluminum detonator sleeves are not used when using mercury fulminate.

Lead azide- white fine-crystalline powder. Lead azide is non-hygroscopic, does not dissolve in water and does not lose detonation ability when moistened. Under the influence of carbon dioxide in the presence of moisture, lead azide turns into carbon dioxide salts, and therefore its sensitivity decreases. Lead azide forms very sensitive and dangerous compounds with copper, so it is pressed into aluminum sleeves. Lead azide is a more powerful explosive initiator than mercury fulminate. The degree of compaction and temperature of lead azide do not affect its sensitivity. Lead azide is not sensitive enough to the fire beam, so it is used in conjunction with lead trinitroresorcinate (TNRS), which is more sensitive to the heat pulse.

TNRS- golden-yellow crystalline powder, darkening in air, with a specific gravity of 3.01. TNRS is physically and chemically stable, slightly soluble in water and slightly hygroscopic, does not interact with metals and therefore can be packed into any shell. In sensitivity it occupies an intermediate position between lead azide and mercury fulminate. In terms of initiating ability, TNRS is used only as an intermediate charge weighing 0.1 g, which causes an explosion of lead azide, and the latter explodes the charge of the secondary initiating explosive.

Secondary initiating explosives are designed to increase the energy of the primary initial impulse imparted by the initiating explosive charge, and to detonate the industrial explosive charge. Secondary initiating explosives are less sensitive to external influences, but have a higher detonation speed, heat of explosion and higher initiating ability compared to primary initiating explosives.

Tetryl- pale yellow crystalline powder. When ignited, it burns quickly, and the combustion can lead to an explosion. Tetryl does not interact with metals. Has high explosive characteristics. It is obtained by nitration of dimethylaniline with nitric acid mixed with sulfuric acid. The bulk density of powdered tetryl is 0.9-1 g/cm 3 , and the density achieved by pressing is 1.7 g/cm 3 . The susceptibility of tetryl is quite high. Mercury fulminate causes the detonation of powdered tetryl with a charge of 0.29 g, and lead azide with a charge of 0.025 g. At a density of 1.68 g/cm 3 tetryl detonates from an explosion of 0.54 g of mercury fulminate. Tetryl is used in CD at a density of 1.6-1.63 g/cm 3 . Tetryl is practically non-hygroscopic, insoluble in water and has relatively high chemical resistance. However, it is capable of interacting quite vigorously with ammonium nitrate, releasing heat. The tetryl mixture is capable of self-ignition, and therefore the production and use of such mixtures is strictly prohibited. From the flame, tetryl ignites and burns quite energetically, and combustion even in relatively small quantities (several tens of kilograms) can lead to detonation. Tetryl has increased sensitivity to mechanical stress. It is used mainly for equipping CDs and making pressed blocks used as intermediate detonators when exploding charges from granulites and water-filled explosives that are not very susceptible to detonation. Tetryl belongs to high-power explosives.

heating element pentaerythristetetranitrate is a white crystalline powder. Non-hygroscopic and insoluble in water. It ignites with difficulty, burns quietly in small quantities, and is one of the most powerful and sensitive secondary initiating explosives. It is used mainly for the manufacture of blast furnaces and as a secondary initiator in some electric detonators.

Examination card No. 13