BG108313A - Modifier of emulsion explosive - Google Patents

Abstract

A modifier of brisance (i.e. shattering effect) for water-in-oil emulsion explosives, composed of a macromolecular component consisting of a prepolymer or polymer with the construction units -[CH2-C(X)=CH-CH2]-in its macromolecule where X is -H or -CH3, and which is terminated by hydroxi- or isocyanate groups of polyisobutylene grouping. Its use in an emulsion explosive reduces its brisance while preserving its working ability and raising the physical consistency of this explosive.

Description

Technical field

The invention relates to a water-in-oil modifier agent, a type of emulsion explosive consisting of a macromolecular component, based on butadiene (liquid rubber) or isobutylene, and will be used in the blasting industry.

BACKGROUND OF THE INVENTION

If we look at water-in-oil type (code name W / O) emulsion explosives as a mixture of chemical components, they are a redox system, as in most mixed explosives. The fuel / oxidant mixture is formulated with a suitable non-explosive sensor, which may be involved in generating explosive nuclei to initiate and expand the chemical reaction in detonation.

In most mixed explosive systems, the primary oxidizing agent is ammonium nitrate, often in combination with other ingredients (eg sodium, potassium, calcium, lithium and the like nitrates) or perchlorates (sodium or ammonium).

The literature describes the use of an almost indescribably wide range of fuels, mainly carbon-containing compounds based on mineral and / or synthetic origin (see, for example, W. Xuguang: Emulsion Explosives. Metallurgical Ind. Press, Beijing, 1994). Commonly used fuels are paraffin oils and waxes, mineral and vegetable oils, petroleum, microcrystalline waxes and other petroleum fractions. The choice of fuel or blend is determined by the rheology requirements of the resultant explosive, as well as by its physical and storage stability.

In certain circumstances, another component of the fuel phase may be metal powders (in particular aluminum) and individual explosives (demilitarized trinitrotoluene and / or hexogenic and demilitarized plastic explosives).

In classic water-in-oil emulsion explosives, it is a rule that the oxidizing and combustion components are present in the liquid state in the discontinuous phase. of the oxidizer, in the form of a supersaturated solution of the oxidizer in the form of microspheres and other water-soluble additives dispersed in the continuous (oil) combustion phase (the continuous phase creates a film on the microspheres of the oxidizing phase). The creation of a continuous and stable boundary between the continuous and discontinuous phases is created by the addition of lipophilic-hydrophilic components (ie emulsifying agents) to the oil phase. The emulsifying agents most commonly used in the technical field are sorption monooleates and / or sequools.

The continuous phase film can be enhanced and the physical stability of the resulting emulsion (emulsion matrix) can be enhanced by the addition of oligomers, polymers and / or copolymers (e.g. W. Xuguang: Emulsion Explosives. Metallurgical Ind. Press, Beijinh, 1994).

The prior art also includes the description and use of oligomers, polymers and bitumen based on isobutylene and butadiene (see for example Can. Pat. Appl. CA 2, 107, 966, 1994 or Jpn. Kokai Tokkyo Koho JP 59, 156, 991 , 1984); here in particular liquid polybutadiene finishing hydroxide has a positive effect, increasing the stability of the emulsion. Hydrophilic polyisobutylene terminations are sometimes found in the production of this type of explosive as polymeric emulsifying agents, the use of which significantly prolongs the working life of the product.

The extremely large separating surfaces in the matrix of emulsion explosives ensure perfect contact between the two phases, the most perfect of all industrial mixed explosives. This fact also means that there is a short reaction zone here in the detonation wave with appropriate sensitization and the initiation of the type of explosive described can be considered equal to the dynamites due to the significant reactivity of the system and the high energy yield used as well as its explosive effect. rock.

Compared to dynamites (ie, explosives containing nitroesters), emulsion explosives have many advantages, such as: their insensitivity to mechanical stimuli, flames, sparks, their high resistance to water and their minimal physiological activity, not only in their own emulsion, but also in the byproducts of the explosion. On the other hand, emulsion explosives can be phlegmatized, even at all insensitive to dynamic shock, in particular to strong compression shock waves caused by the detonation of a projectile near the rock.

Another disadvantage is that only one category of mine-safe explosives can be manufactured from emulsion explosives.

These two drawbacks result in the relatively high brilliance (ie crushing effect) of this type of explosive.

The most widespread principle in the process of constructing mine harmless explosives containing nitroesters is to include cooling additives (most commonly sodium chloride) or a cooling ion of the exchange system (eg, a mixture of ammonium chloride and sodium nitrate) in the explosive mixture. This results in a reduction in the operability and brilliance of the resulting explosive, compared to nitro-explosives without cooling additives. However, as shown in the exemplary embodiment of this invention, analogous incorporation of sodium chloride up to 10% by weight of emulsion explosives reduces their operability but increases their brilliance. In this case, the cooling effect of the additives mentioned above can be eliminated to some extent. The problem of brilliance in emulsion explosives is therefore a decisive factor in the process of constructing mine harmless explosives on this base (base). The known literature pays little attention to systematic studies of the effect on the brilliance of emulsion explosives arising from the chemical composition of the components of the reduction and oxidation system of these explosives.

SUMMARY OF THE INVENTION

According to the procedure described in this invention, the brilliance of a water-in-oil emulsion explosive is modified by the addition of macromolecular components based on butadiene and isobutylene to the oil phase. One advantage of this procedure is that a relatively small amount of these macromolecular components (0.5 to 1.8% by weight of the resultant explosive) significantly reduces the brilliance while maintaining the emulsion explosive's performance while maintaining stability and modification of the consistency of the resulting explosive, so that when the cooling additives are incorporated into its composition, it becomes an explosive first category of mine safety. Another advantage of the procedure described in this invention is the availability of those micromolecular components that are manufactured industrially for the needs of the plastic and rubber industries, as well as for the specialty types of explosives produced.

An exemplary embodiment of the invention

The use of macromolecular components based on butadiene and isobutylene as described in this invention has not been described previously in the literature. It is documented through the following examples, which in no way preclude possible uses.

Example 1

A solution of ammonium nitrate (AN) or sodium nitrate (SN) and / or calcium nitrate (CN) and / or sodium perchlorate (SP), with a temperature of 85-100 ° C and capable of containing other water-soluble components, such as sodium chloride (NaCl), glycol or the like are fed inside an emulsion apparatus containing a warm oil phase (80-85 ° C) which is stirred vigorously (in a mixer of 1000 to 1500 rpm). This oil phase consists of mineral oil (with an average mass of 910 Kg.m ', with a maximum curing point of -5 ° C and a minimum flash point (66 ° C) and / or crude paraffin (curing point 39 ° C). , ignition temperature 220 260 ° C, and an oil content of about 1.5% by weight) plus sorbent monooleate (M) and / or sorbent sesquololate (S), with the possibility of containing macromolecular components as well. the mixture should be stirred for more than 5 minutes. The emulsion matrix thus obtained is is immobilized in a homogenizer by the addition of silicates (MB) with an average size of 70 pm, and possible modification by the addition of solid sodium chloride (NaCl) with an average grain size of 80 pin. The resultant explosive mixture is loaded (filled) into plastic tubes to make cartridges weighing 400 g and a diameter of 32 mm The charge mass velocity of detonation (D, using number 8 detonator) and relative operability (RWA) were determined for each cartridge. In summary, the composition of the individual mixtures prepared in accordance with this procedure is given in the Table together with the relevant values for p, D and RWA.

The following macromolecular components were added to the oil phase:

liquid polybutadiene rubber (LBH) ending with hydroxyl groups of average molecular weight 2400 - 3100, polydispersed index cc 1.1 and hydroxyl content cc 0.7 mmol.g ' ¹ , in which the number of structural constituent units of their macromolecule units - [CH ₂ -CH = CH-CH ₂ ] - is cc 44 to 57.

Liquid isocyanate copolymer (LBD ending in isocyanate toluene groups) with polybutadiene straight chain, with a mean molar weight of 3200 - 3800, polydispersed index of csa 1.3 and quantity of functional groups csa 2.2, in which the number of structural constituents of their macromolecule [CH ₂ -CH = CH-CH ₂ ] - is also c 44 to 57.

Solid polyisobutadiene (PIL) copolymer of 2 mol% of isoprene with an average molar weight of 200,000 of the main structural model

- [- (C (CH ₃ ) ₂ -CH ₂ -) _m - (- CH ₂ -C (CH ₃ ) = CH-CH ₂ -) _n -] _y where w »n

In some emulsion mixtures containing LBD, in the specific mixtures 1.1, 1.3 and 1.4 in the Table, structure-forming catalysts were used. This produces plastic, well-shaped dies that can be filled (filled) with crystalline additives up to 50% of their mass without losing the cohesion of the final mixture. Macromolecular additives also extend the durability of emulsion explosives containing them (minimum 6 months) compared to emulsion explosives without them (3-6 months durability).

Example 2

Made according to Czechoslovak Patent No. 229 745 (1982): a solution of ammonium nitrate (AN) and sodium nitrate (SN) heated to 80-90 ° C are placed in an emulsion apparatus. A solution of oleic acid in a mineral oil is added thereto, followed by an aqueous solution of sodium hydroxide. The mixture was stirred well to an emulsion form. This emulsion is sensitized in a homogenizer by the addition of expanding perlite. This produces an emulsion explosive containing 62.9 mass% AN, 13% CN, 12% water and 2.5% sodium hydroxide, 2.8% oil, 2.8% oleic acid, 4% expanded perlite, which is registered under the name Emsit. Its average mass density is 1.06 g.cm ' ³ , the detonation rate D = 4817 m.s' ¹ and the relative operating capacity RPS = 69.5%

Example 3

This example expresses the graphical dependence of the relative operability of the emulsion explosives in Example 1 and Example 2 on their brilliance, expressed by the product of average charge weight and the square of the detonation velocity, expressed as p ^K D ² . This follows from the dependence that the macromolecular components of the oil phase in Example 1 significantly reduce the brilliance of the respective emulsion explosives, compared to explosives that do not use these components (including the Emsit explosive in Example 2). The effect is important for mine-safe explosives. Graphic dependence means that in both groups of emulsion explosives, one increase in the amount of high molecular weight solids results in a decrease in the RWA value and an increase in the brilliance (this is also true for mineral sessibilized content).

Example 4

When 1050 g of the explosive mixture 1.7 of the Table in Example 1 is detonated in the form of 32 mm diameter cartridges, this does not ignite a methane-air mixture with 9% by volume of methane content or 1200 g of coal dust mixed with air where the powder has a concentration 300 gm ' ³ . The limit mass for this explosive (32 mm diameter) was set at 1241 ± 72 g. The gas products of their detonation do not include nitrogen oxides.

Industrial applicability

The production of a water-in-oil emulsion is suitable to be completed as an emulsion explosive with reduced fragmentation and preserved fragmentation effects, for example an explosive with increased safety for mines.

Patent Claims

Claims (2)

1. Water-in-oil modifying agent emulsion explosives in which the discontinuous phase consists of an aqueous solution of inorganic nitrates and / or perchlorates, possibly also containing other inorganic or organic components and possibly also containing a cooling component of the inorganic chloride group, characterized in that it consists of a copolymer or a polymer with constituent units - (CH 2 -C (X) = CH-CH ₂ ] - in its macromolecule, where X is -H or -CH 3 and which is terminated by hydroxy or isocyanate groups or polyis butylene fractions. Emulsion explosive modifying agent according to claim 1, characterized in that it represents 0.5 to 1.8%, preferably 0.6 to 1.57% by weight of the explosives calculated from the mass of the final emulsion explosives.