CS267174B1 - Explosive mixture based on inorganic nitrates - Google Patents

Abstract

The essence of the solution is an explosive mixture containing 50 to 99.9% by weight of inorganic nitrate, 0 to 40% by weight of combustible and/or explosive compound and 0.1 to 10% by weight of hollow closed fibrous particles with an internal diameter in the range of 1 cm to 3 mm and/or the same amount of porous short fibrous particles with a length of 1 µm to 15 mm with an internal surface of 5 to 500 The solution is useful especially in the formulation of the composition of industrial explosives and their application.

Description

2 EN 267 174 B1

The present invention relates to modified inorganic nitrates for the production of explosive mixtures and / or explosive mixtures themselves, which provide the desired sensitivity to the transmission of detonation.

Mixed explosives are becoming increasingly important in both civilian and military applications. The most widely used oxygen donor is ammonium nitrate, but sodium nitrate and calcium nitrate are widely used. These explosives can be divided into two main groups: I. ammonium nitrate mixture with fuel; IX. ammonium nitrate mixtures, respectively. sodium or calcium nitrate, water with an additive and / or emulsifier and explosive compound or sensitizer.

The first group explosives may be produced by stable process equipment, but are more often produced on site (i.e., in mobile mixing devices or directly in boreholes). Ammonium nitrate is mixed with fuel, which is a wide variety of organic compounds, but paraffins, fuel oil, or diesel are most commonly used. These mixtures have an approximate zero oxygen balance, corresponding to 94% by weight. ammonium nitrate and 6 wt. diesel or fuel oil in explosives; said fuel content will increase the explosion heat value from 1470 kJ and kg for ammonium nitrate up to 3,738 kJ.kg 1, which is proportionally an increase in explosive working capacity compared to ammonium nitrate alone. Explosives of this type are known in the Czech Republic under the code name DňP, abroad are similar mixtures designated ANDK (in GDR), ANC (in Germany), Igdanit (in the USSR), ANFO or ANBA (in the USA and Great Britain). When the fuel is a coal dust metal powder and the like, the carbonated nitrates and the NCN code are also mixed.

Second-class explosives characterized by relatively simple and low-tech production. We are known as TPV (plasticized water explosives); in the United States and Canada for slurry consistency called "Slurry Explosives". At present, the most widely used explosives of this type are, according to the method of sensitization, namely: a) "Slurry Explosives" (SR), which are sensitized by an additive of explosive nature (trinitroluene, hexogen, nitroesters, nitrates of alkanol or alkylamines, hydroxialkyl- nitrates and po); (b) "Slurry Blasting Agents" (SBAs) which do not contain explosive additives and are sensitized by non-explosive components, most commonly aluminum dust (eg, SovietAquanals) and / or other substance (fuel oil, cellulose, polyvinyl chloride powder, sulfur, paraffin, hexamethylenetetramine, polyols, sugars and the like) and aerating additives (expanded perlite, glass pulp or hollow beads, cork, polystyrene, plated ammonium nitrate, zeolite and the like), or gas-releasing substances (peroxides, nitrites, carbonates, 1,5-endomethylene-3,7-dinitroso-1,3,5,7-tetraazacycloctane and others).

The invariability of physical stability, ie the avoidance of separation of the constituents of these "Slurry" subgroups while maintaining fluidity or plasticity of the composition, is ensured by the addition of a gelling agent (plasticizer) such as guargur and its alkyl derivatives, polyvinyl alcohol, sodium or ammonium salts of carboxymethylcellulose, oxyethylcellulose, other polyacrylamides.

The youngest type of "slurry" explosive composition is a water-in-oil emulsion, code-named W / 0, or an oil-in-water emulsion, code-named O / W. The production of the W / O compositions consists in introducing aqueous solutions of the explosive components into the hydrophobic liquid (fuel oil, diesel oil, etc.) and making the composition! 0 / W is reversed. These emulsions are stabilized by dispersants such as fatty acid salts (especially stearic or oily), fatty acid esters (eg decglycerol decaeate, decaglycerine deca stearate), partially esterified polyols by fatty acids (eg monostearate, monooleate, monopalmitate CS 267 174 B1 3 or tristearate sorbitol, mono- or diglicerides of fatty acid-forming fats), daleyalkylphenylsulfonates, soybean lecithin, other copolymers of ethylene oxide with propylene oxide. Emulsion explosives may be sensitized by nitro compounds, most commonly nitromethane, or other nitroparafins, but in technical practice the most useful is their sensitization by airborne or gas-releasing additives. Low production costs, high safety of handling and own production and the possibility of blasting machines are characterized mainly by mixtures based on ammonium nitrate.

This is the main reason why the exploitation of explosives of the DAP, TFV, W / 0 and 0 / W types in the technical practice dominates the exploitation of other types of industrial explosives. An analogous trend can also be found in the field of explosives for military purposes (aluminized aqueous gels of ammonium nitrate, for example, sifted into some types of aerobic bugs, trinitrotoluene is replaced by liquid compositions based on aqueous solutions of hydrazine nitrate, etc.).

When solid inorganic nitrates are applied to produce mixed explosives, it is important that they are in bulk form; this is achieved by eliminating, respectively. by suppressing their performance by the addition of anti-caking agents such as ferric salts of fatty acids, paraffins, powdered urea-formaldehyde condensates, and the like, i.e., chemical technology products whose implementation is associated with considerable energy, equipment, buyer and podium requirements, including corresponding environmental pollution. In the event that nitrates are not treated against sintering, mixtures are already produced during their transport to their agglomeration; Here, then, it is necessary to include nitrate milling in the process of producing explosives, which in turn is related to the demands on energy, equipment and human labor. Sintering is an undesirable phenomenon in manufactured mixed explosives, where it is particularly troublesome in terms of the functionality of these products. Chemical technology products with considerable demands on energy, equipment, human labor and podium funds are all so far used sensitizers, many of which are increasingly significant and economically more attractive use in different sectors of the national economy Therefore, research and development efforts are needed to focus on the search for technically, economically more environmentally friendly anti-caking and sensitizing ingredients of mixed explosives, respectively, inorganic nitrates.

According to the invention, the explosive mixture based on inorganic nitrates contains 50 to 99.9 wt. % of inorganic nitrate, preferably 75 to 95 wt. ammonium nitrate, 0 to 40% by weight of combustible and / or explosive compound, preferably 10 to 20% by weight; 2,4,6-trinitrotoluene and 0.1 to 10 wt. hollow closed fibrous particles having an internal diameter in the range of 1 (µm to 3 mm and / or the same amount of porous short fibrous particles of length 1 (µm to 2 - 15 mm) with an inner surface of 5 to 500 m, g, preferably based on polypropylene. of the present invention is the chemical stabilization of the starting nitrates or explosive mixtures with their contents, their content or sensitization of these mixtures, the addition of technically economically available additive, ie short fibrous particles, due to the defined physical properties of the fibrous particles, these sensitizers - an aerator explosive mixtures; defined short fiber particles within the meaning of the present invention, thus allowing even small-diameter charges to be realized and suppressing the occurrence of "failures" in their application, resulting in a beneficial effect on the safety and economy of blasting machines.

The higher effect achieved by the present invention has not been described in the literature so far, but it is exemplified in the following which, however, does not in any way limit the scope of the present invention. the variability of the process of the invention. Example 1 There are short particles of hollow polypropylene fiber 0 50 µm, wall thickness 8 (Um obtained by melt spinning polypropylene (MOSTEN D3) with a flow index of 27 g / 10 min at a temperature of 250 ° C, winding speed of 1,500 m / min EXAMPLE 2 Short particles of a porous polypropylene fiber spinning plug are available as in Example 1, except that the fiber is thermofixed to isothermal conditions at 140 ° C, cold 100 ° C. The fibrous particles contain about 15% by volume of the microcavities of an average size of 10 nm 2 -1 (distribution from 1 to 120 nm) and an internal specific surface area of 220 µg. ammonium containing 96.9% by weight granules with a diameter of 1-3 mm (the remainder of the particle with a diameter of less than 1 mm) are added short fiber particles of 1 mm in length, S as specified in Examples 1 and 2 (in a 1: 1 weight ratio) such that mixtures containing 97 wt. ammonium nitrate, 2 and short fibrous particles and up to 1% w / w. This nitrate only tended to form agglomerates after 5 months of storage at a temperature of about 25 ° C in polyethylene-sacks packed on top of each other in four layers, but could be easily broken by handling the bag. EXAMPLE 4 From Technical 2,4,6-Trinitrotoluene, Ammonium Nitrate and Hollow Polypropylene Fiber Specified in Example 1, chopped to a length of max. 0.1 mm, Amatol is the most commonly prepared blend (chopped fiber is added to the mixture for up to 10 minutes prior to completion of homogenization). ), consisting of 14 wt. 2,4,6-trinitrotoluene, 2% polypropylene fiber and 84% wt. ammonium nitrate. For comparison, Standard Amatol 80/20, made up of 20 wt. 2,4,6-trinitrotoluene and 80 wt. Amatol 84/16 containing 16 wt. 2,4,6-trinitrotoluene and 84 3 wt. ammonium nitrate. Said mixtures for charge density 3 100 kg / m are characterized in Table 1 by the following parameters:

Table 1

Parameter of the Invention Amatol 80/20 84/16

Calculated values: - volume of explosion gases (dm3.kg “l) 920 900 910 - oxygen coefficient 0.99 1.02 1, -maximum explosion heat (kV.kg" l) 4 091 4 235 4 174 - explosion heat corrected (kV .kg “l) 3,690 3,860 3,900 -Specific energy (kv.kg 1) 855,862 87Q.

Experimental values: -3-dump weight (kg.m) 790-830 -transfer of detonation from cartridge 33 to 37200g TNT to distance (cm) 800-85025 to 30-start melting (° C): TNT 77.7 AN 160.6 - exothermic 184.6

decomposition (° C) from DTA -vacuum stability test at 0.185 125 ° C (cm3.g ~ l.hod '·' ·) -concrete speed (km.s 1) 4.1 to 4.6 77.8 164 1,196.6 0.026 4.2 to 4.8

Claims (2)

Note: TNT = 2,4,6-trinitrotolueneAN = ammonium nitrateDTA = differential thermal analysis It can be seen from Table 1 that the addition of polypropylene hollow fiber activates the corresponding mixture both for thermal decomposition and for detonation sensitivity. The same effect is achieved by the addition of hollow or porous fibrous particles of polyethylene, polyvinyl chloride, polyester, polyacrylonitrile and polyamide. SUBSTITUTE Explosive mixture based on inorganic nitrates, characterized in that it contains 50 to 99.9 wt. % of inorganic nitrate, preferably 74 to 95 wt. ammonium nitrate, 0 to 40% of a combustible and / or explosive compound, preferably 10 to 20% by weight; 2,4,6-trinitroluene and 0.1 to 10 wt. hollow closed fibrous particles having an inner diameter in the range of 1 µm to 3 mm and / or the same amount of porous short fibrous particles of length -1 -1 (up to 15 mm with an inner surface of 5 to 50 m, g, preferably polypropylene based).