RU2078751C1 - Explosive substance - Google Patents

Abstract

FIELD: mining industry. SUBSTANCE: explosive substance for shooting at open and underground working contains (in wt %): urea or hexamethylenetetramine, 0.5-33.0; mineral oil, 0.5- 8.5; water, 5.0-20.0; sensitizer, 0.5-2.0; silica gel (on conversion to silica), 0.5-5.0; oxidant, the balance. As sensitizer, substance may contain calcium carbonate, thiourea, or sodium nitrite, or their mixture with a surfactant. EFFECT: improved performance characteristics. 2 cl, 1 tbl

Description

 The invention relates to the production of mixed water-containing explosives (BB) and can be used in mining during explosive blasting in open and underground operations.

 Known waterproof water-containing concentrated or high-density explosive mixtures of water gel with ANPO-HANPO, slarri (L.V. Dubnov, N.S. Bakharevich, A.I. Romanov. Industrial explosives. M. Nedra, 1988, 358 S. V. L. Baron, W.H. Cantor, Technique and Technology for Blasting in the USA, M. Nedra, 1989, pp. 99-100; UK Application N 1,445,594 Ncl C 1 D; US Patent N 3,475,238 Ncl 149-109; U.S. Patent No. 3,73053 N.C. 149-41).

 However, these explosives use scarce organic gelling agents (thickeners) guargam, polyacrylamide, carboxymethyl cellulose.

BB is also known, taken as a prototype, closest to the proposed one (UK Application N 2112373 N.cl C 1 D. Flowing BB). EXPLOSIVES contains, as a first component, a molten oxygen-releasing salt, for example ammonium nitrate, flowing in the temperature range from -10 to +90 ^° C and melt-soluble combustible material, for example urea, and as a second component, oil-treated ammonium nitrate particles. BB also contains water, a thickener, crosslinking agents and a sensitizer — a dispersed gas mixture with a stabilizer (SAS), for example, condensation products of formaldehyde and naphthalenesulfonates.

 The disadvantage of this explosive is the relatively low gel strength due to the use of an organic polymer gelling agent. The structure of the gel formed by the organic polymer is not rigid enough, therefore, a borax crosslinking agent, potassium dichromate, and sodium dichromate are additionally used. A disadvantage is the use of an organic surfactant as a stabilized dispersed gas mixture, which at high hydrostatic pressures cannot inhibit the migration of gas bubbles in the explosive charge volume.

 The aim of the invention is to increase the sensitivity of explosives to detonation pulses at high hydrostatic pressure.

 To achieve this goal in the well-known explosives, including an oxidizing agent, water, urea or hexamethylenetetramine, mineral oil, a sensitizer, a gelling agent, silica gel is used as a gelling agent, in the following ratio of components, in wt.

Urea or hexamethylenetetramine 0.5 33.0
Mineral oil 0.5 8.5
Water 5 20.0
Sensitizer 0.5 2.0
Silicic acid gel (in terms of silicon dioxide) 0.5 5.0
Oxidizer rest
Also, as a sensitizer, you can use CaCO ₃ , thiourea, NaNO ₂ or their mixture with a surfactant.

 The signs that distinguish the proposed solution from the prototype are new, because when conducting a search in patent and scientific literature, no explosives of this qualitative and quantitative composition were identified. Therefore, claimed as an invention, the technical solution meets the criteria of "novelty" and "inventive step".

 The introduction of a new ingredient changes the qualitative and quantitative composition of the mixture. So, when the gelling agent in the explosive is more than 5%, the strength of the explosive structure increases, but the viscosity of the explosive increases, which makes it difficult to mix, when the gelling agent is less than 0.5%, the water resistance of the explosive decreases. When the content of the sensitizer is more than 2%, the water resistance of the explosives also decreases; when the content of the sensitizer is less than 0.5%, the sensitivity to the detonation pulse and the explosion energy of the explosives decrease. A water content of more than 20% leads to a decrease in sensitivity to detonation pulses and explosive energy of explosives, a water content of less than 5% leads to an increase in viscosity and temperature of its preparation. The content of fuel soluble in the melt of more than 33% leads to a decrease in the water resistance of explosives and a negative oxygen balance, while the content of fuel soluble in the melt below 0.5% leads to an increase in the viscosity and temperature of preparation of explosives. When the content of insoluble fuel in the melt is more than 8.5%, the viscosity and temperature of the preparation of explosives also increase, changes to a negative oxygen balance, and when the content of insoluble fuel in the melt is less than 0.5%, the water resistance of the explosives decreases.

Example 1. A mixture of 75% melt and 25% dry matter. At 60 ^° C., 0.5% silica gel is mixed in a mixer with water 5% is dissolved 36.5% sodium nitrate and 33% urea is separately prepared as a mixture of 24% sodium nitrate, 0.5% mineral oil and 0.5% thiourea. Before loading into the well, both parts are mixed.

Example 2. A mixture of 75% melt and 25% dry matter. At 25 ^° C., 5% silica gel is mixed in a mixer with water; 20%; potassium nitrate is dissolved; 49.5%; and urea, 0.5%; separately, a mixture of 46% potassium nitrate, 3% mineral oil and 1% thiourea is prepared. Before loading into the well, both parts are mixed.

Example 3. A mixture of 50% melt and 50% dry matter. At 20 ^° C., 3% silica gel is mixed in a mixer with water 10% is dissolved 20% ammonium nitrate and 7% urea is separately prepared a mixture of 46% ammonium nitrate, 1% mineral oil and 1% thiourea. Before loading into the well, both parts are mixed.

Example 12. A mixture of 25% melt and 75% dry matter. At 15 ^o C, 0.5% silica gel is mixed in a mixer with water 11%; ammonium nitrate 12.5% is dissolved; urea 1% is separately prepared as a mixture of 70% ammonium nitrate, 4.5% mineral oil and 0.5% thiourea. Before loading into the well, both parts are mixed.

 Other examples of specific use, the prototype and their characteristics are shown in the table.

 The table shows that the critical diameter on the open surface of the prototype and the proposed explosive is almost equal, with an increase in hydrostatic pressure to 0.15 MPa, there is no sensitivity to the detonation pulse of the prototype, and the proposed explosive detonates without fail.

 It can be seen from Example 16 that a silica gel content of less than 0.5% leads to a decrease in water resistance. Example 17 shows that an increase in the silica gel content of more than 5% leads to a deterioration of the technological properties of explosives.

 The use of silicic acid gel as a gelling agent allows us to expand the raw material base of the proposed explosives, because silicate rocks raw materials for silicic acid gel are ubiquitous. Guaram, PAA and CMC are extracted only from organic raw materials, the cost of extracting organic gelling agents is higher than inorganic. Silicic acid gel has a more rigid structure; when dehydrated, it partially retains volume (silica gel), in contrast to organic gellants, which ensures the proposed explosive distribution of gas bubbles in the charge volume until the explosive solidifies. Also, a more rigid lining of gas bubbles during the solidification of the explosive creates significant pressure when the bubbles collapse in the detonation wave, which increases the sensitivity of the explosive to the detonation pulse.

Claims (1)

 1. Explosive, including an oxidizing agent, water, urea or hexamethylenetetramine, mineral oil, a sensitizer, a gel, characterized in that as a gel, it contains a gel of silicic acid in the following ratio, wt. Urea or hexamethylenetetramine 0.5 33.0
Mineral oil 0.5 8.5
Water 5 20
Sensitizer 0.2 2.0
Silicic acid gel (in terms of silicon dioxide) 0.5 5.0
Oxidant Else
2. The substance according to p. 1, characterized in that as a sensitizer it contains calcium carbonate, or thiourea, or sodium nitrite, or a mixture thereof with a surfactant.

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