EA012307B1 - Molded explosive composition - Google Patents

Abstract

The invention relates to shooting, in particular, to compositions of mold explosives used for production of detonator pellets, blasting cartridges and other articles for use in blasting operations in mining industry. The composition of mold explosives comprises pentaerythrite tetranitrate (PETN) or phlegmatized PETN, or utilized PETN in the amount of wt % 15-71 having particle size of 0.45 mm or less and trinitrotoluene or utilized trinitrotoluene as remainder, wherein it comprises PETN which at density 1.62 g/cmhas velocity of detonation 7910 v/s. The composition comprises PETN with specific surface being at least 150 cm/g, it comprises pentolit as the utilized PETN. The less PETN particle size, the slower they precipitate in trinitrotoluene melt (resulting their more uniform distribution by height). The proposed composition provides reduced amount of harmful gases released in explosion due to lesser PETN particle size.

Description

The invention relates to blasting, and in particular to compositions of cast explosive materials used in the manufacture of detonator drafts, cartridges and other products that are used for blasting in the mining industry.

Explosive materials (VM) in accordance with the main areas of their application are divided into four groups [1, p. 18-20]:

1) initiating,

2) blisant,

3) gunpowder,

4) pyrotechnic compositions.

Initiating BMs are mainly used in detonator capsules.

High explosive explosives are used as explosive charges. Unlike initiating VMs, they have significantly greater resistance to external influences. The main representative of BM of this group is trotyl (trinitrotoluene).

Pressed TNT is used in T-400G type detonators and is used for blasting charges in wells [2, sheet 2].

However, during the explosive conversion of TNT, a large number of harmful gases are formed: nitrogen oxides and carbon monoxide. It is known that during the explosion of TNT in the form of granules (granulotol) harmful gases are formed in an amount of 275 l / kg [3, p. 33, tab. 1 (1st line)]. A large amount of harmful gas during the explosion of TNT is formed due to its significant negative oxygen balance, which is -74.0% [4, p. 20, tab. 1 (item “Initial active components”, 8th line from the top)].

Closest to the claimed invention in terms of essential features is the patent "Composition of cast explosive (paragraph 3 of the claims)" [5, p. 6], which is adopted as a prototype. The composition contains hexogen or phlegmatized RDX 18-60%, TENA (pentaerythritol tetranitrate) 5-39% and TNT - the rest. The composition contains RDX or phlegmatized RDX and PETN with particle sizes not exceeding 0.5 mm.

The closest oxygen balance of the prototype relative to zero is -37.1% [5, p. 3]. When the prototype is blown up, the amount of harmful gases from 174 to 182 l / kg is formed [5, p. 5, table. The results of comparative tests. Option 2].

The proposed composition allows to reduce the amount of harmful gases in comparison with the prototype.

The composition of the cast explosive material containing trotyl or disposed of trotyl and TEN, or a phlegmatized TEN, or a recycled TEN, contains a TEN for national economic purposes, or a phlegmatized TEN, or a recycled TEN with particle sizes of not more than 0.45 mm in the following ratio of components, wt.%: heating elements for economic purposes, or phlegmatized heating elements, or disposed heating elements - 15-71, TNT or recycled TNT the rest, while it contains a heating element, which at a density of 1.62 g / cm ³ has a speed detonation 7910 m / s.

The composition contains a heater with a specific surface area of at least 150 cm ² / g.

The composition as a phlegmatized heating element contains pentolite.

The composition contains recycled heating elements and (or) recycled TNT.

The proposed composition provides a reduction in the amount of harmful gases after its explosion in comparison with the prototype due to the additional content of the heater (completely replacing RDX) and the reduced size of its particles.

The oxygen balance of the heater is -10.1%. [4, p. 20, tab. 1 (item "Initial active components", 10th line from the top)]. The oxygen balance of the composition containing 71% TENA and 100-71 = 29% TNT is

7 .. (- 10.1) + 29. (- 74) _%

one hundred

Therefore, the composition has the closest oxygen balance relative to zero is -28.6%, which is closer to zero oxygen balance compared to the closest oxygen balance relative to zero of the prototype, equal to -37.1%. The closer the oxygen balance of the compounds to zero, the less harmful gases are formed during their explosive conversion. It is not advisable to increase the content of TEN in the composition of more than 71%, since its molding properties are deteriorating. With a decrease in the heating element content of less than 15%, the formation of harmful gases significantly increases and the sensitivity of the composition to the initiating pulse decreases.

The composition contains a crystalline heating element for economic purposes, which at a density of 1.62 g / cm ³ has a detonation speed of 7910 m / s and is not included in the list of dual-use materials and related technologies used for nuclear purposes, for which export control is carried out .

Dual-use materials include powerful explosives or mixtures containing

- 1 012307 more than 2% of any explosive with a crystalline density of more than 1.8 g / cm ³ having a detonation velocity of more than 8000 m / s [6, clause 6.3.1. d)].

An additional reduction in the amount of harmful gases during the explosive transformation of the proposed composition occurs due to a decrease in the particle size of the heating element.

TEN particles for national economic use are used with sizes not exceeding 0.45 mm. The smaller the particles in size, the slower they are deposited in the TNT melt (lead to a more uniform distribution in height) and significantly increase the surface of the explosive transformation of these particles.

In the prototype, the particle size is not more than 0.5 mm (0.05 cm). The average particle size in the prototype is 0.05 / 2 = 0.025 cm, the average particle surface is 4π (0.025 / 2) ² = 0.00196 cm ² . The average particle mass is (4/3) π (0.025 / 2) ³ (1.77) = 0.0000145 g, where 1.77 g / cm ³ is the density of the TENA single crystal. The ratio of the average surface of the particles to their average mass (specific surface) is 0.00196 / 0.0000145 = 135 cm ² / g.

In the proposed composition, the particle size is not more than 0.45 mm (0.045 cm). The average size in this case is 0.045 / 2 = 0.0225 cm, the average particle surface is 4π (0.0225 / 2) ² = 0.00159 cm ² , the average particle mass is (4/3) π (0.0225 / 2) ³ (1.77) = 0.0000106 g. The ratio of the average surface of the particles to their average mass (specific surface) is 0.00159 / 0.0000106 = 150 cm ² / g. Therefore, the specific surface area of the particles of the proposed composition is more than 150/135 = 1.11 times that of the prototype.

With a decrease in particle size, its specific surface increases. For a particle size of not more than 0.45 mm, a specific surface area of at least 150 cm ² / g corresponds.

The dispersion of the heating element should be at least 150 cm ² / g.

Pentolith is used to obtain a more uniform composition of the proposed.

When the proposed composition is blown up, the amount of harmful gases from 134 to 173 l / kg is formed (see table. Results of comparative tests), which is less than that of the prototype, which varies from 174 to 182 l / kg.

The proposed composition has a high sensitivity to the initiating impulse from all existing initiation systems and a high initiating ability of low-sensitivity charges containing grammonites, granulites, ammonites, emulins, etc.

The proposed composition is used in the manufacture of checkers-detonators, drill holes (drill holes-detonators) and other products.

Information sources

1. F.A. Baum, K.P. Stanyukovich, B.I. Shekhter. Explosion physics. Gos. ed. Phys.-Math. lit., M., 1959.

2. Checkers-detonators for industrial blasting. Technical conditions OST 84-411-80.

3. L.V. Korneeva, E.V. Kolganov, B.N. Kutuzov. Production of industrial explosives and materials for mining enterprises. Mountain Journal. 2003, No. 10.

4. Z. G. Pozdnyakov, B. D. Rossi. Handbook of industrial explosives and explosives. Ed. the second one. M., Nedra, 1977.

5. Patent KI 2270181 C1, 08/03/2004.

6. List of dual-use equipment and materials and related technologies used for nuclear purposes in relation to which export control is carried out. Approved by Decree of the President of the Russian Federation of January 14, 2003 No. 36.

Claims (3)

CLAIM 1. The composition of the cast explosive material containing trotyl or utilized trotyl and heating elements, or phlegmatized heaters, or utilized heating elements, characterized in that it contains the heaters for national economic purposes, or phlegmatized heaters, or utilized heating elements with particle sizes not exceeding 0, 45 mm in the following ratio, wt.%: TEN for national economic purposes, or phlegmatized TEN, or recycled TEN - 15-71, TNT or utilized TNT - the rest, while it contains TEN, which at STI 1.62 g / cm ³ has a detonation velocity of 7910 m / s. 2. The composition according to claim 1, characterized in that it contains a heating element with a specific surface area of at least 150 cm ² / g. 3. The composition according to claim 1, characterized in that it contains pentolite as phlegmatized PETN.