RU2286326C2 - Modifying agent for emulsion explosive substance - Google Patents

Abstract

FIELD: explosive substances.

SUBSTANCE: invention relates to emulsion explosive substances. Invention proposes a method for modifying the brisance of emulsion explosive substance prepared by using emulsion of type "water-in-oil" (reverse emulsion) containing oily phase and dispersed phase consisting of inorganic nitrates and/or perchlorates an aqueous solution that can comprise also inorganic or organic components and involving addition the brisance modifying agent to the oily phase. Prepolymer or polymer with links -[CH₂-C(X)=CH-CH₂]- as the brisance modifying agent wherein X means hydrogen atom (-H) or methyl group (-CH₃) in macromolecule terminating by hydroxyl or isocyanate groups or polyisobutylene groups. The dispersed phase of emulsion explosive substance can comprise a cooling component in form of inorganic chloride group. Invention is directed for reducing the brisance of emulsion explosive substance with retaining its working properties.

EFFECT: improved and valuable properties of explosive substance.

2 cl, 1 dwg, 1 tbl, 4 ex

Description

Technical field

The present invention relates to a brisance modifier of emulsion explosives manufactured using a water-in-oil emulsion (reverse emulsion) consisting of a macromolecular component based on butadiene (liquid rubber) or isobutylene.

State of the art

If we consider emulsion explosives manufactured using reverse emulsion (codenamed "W / M") as a mixture of chemical components, they are a redox system, like most mixed explosives. The mixture of fuel and oxidizer is complemented by a suitable non-explosive sensitizer, which is able to participate in the creation of hot nuclei to initiate and spread the chemical detonation reaction.

In most mixed explosives, the main oxidizing agent is ammonium nitrate, often in combination with other nitrates (e.g. sodium, potassium, calcium, lithium, etc.) or perchlorates (sodium or ammonium). An almost indescribably wide gamut of fuels is used, mainly carbon compounds of the mineral and / or synthetic types (see, for example, W.Xuguang: Emulsion Explosives. Metallurgical Ind. Press, Beijing, 1994). Most often, paraffin oils and waxes, mineral and vegetable oils, oil, microcrystalline waxes and other fractions of oil are used as fuels. The choice of fuel or fuel mixture is determined by the requirements for the rheology of the final explosive, as well as its physical and storage stability. In certain circumstances, another component of the fuel phase may be metal powders (especially aluminum) and individual explosives (trinitrotoluene and / or hexogen and ballistites withdrawn from military circulation).

In classic emulsion explosives manufactured using reverse emulsion, the oxidizing and fuel components are usually contained in a liquid state: the dispersed phase of the oxidizing agent in the form of a supersaturated oxidizing agent in the form of microspheres and other water-soluble additives is dispersed in a dispersive (oil) fuel medium (dispersion medium creates a film of microspheres of the oxidizing phase). Creating a permanent stable border between the dispersion medium and the dispersed phase is achieved by adding lipophilic - hydrophilic components (i.e. emulsifiers) to the oil phase. In practice, the most widely used emulsifiers are sorbitan monooleates and / or sorbitan sesquioleates.

The film on the dispersion medium can be enhanced, and the physical stability of the resulting emulsion (emulsion matrix) can be increased by adding oligomers, polymers and / or copolymers (see, for example, W.Xuguang: Emulsion Explosives. Metallurgical Ind. Press, Beijing, 1994 ) Isobutylene and butadiene-based oligomers, polymers and bitumens (see, for example, Canadian Patent Application 2,107,966, 1994 or Jpn. Kokai Tokkyo Koho JP 59,156,991, 1984) are also described and used in the art: in such cases, liquid polybutadiene with hydroxides on the ends of the chain have a particularly positive effect, increasing the stability of the emulsion. Polyisobutylene with hydrophilic groups at the ends of the chain are sometimes used in the manufacture of explosives as polymer emulsifiers, which can significantly increase the durability of the final product.

The extremely large interfaces in the emulsion explosive matrix provide very good contact between the two phases in the most advanced of all industrial mixed explosives. This also means that in the detonation wave there is a short reaction zone: with suitable sensitization and initiation, the described type of explosive can be considered equal to dynamites due to the significant chemical activity of the system and the high yield of useful energy, and can also be used when blasting hard rocks.

Compared to dynamites (i.e., explosives containing nitroesters), emulsion explosives have a number of significant advantages, such as the lack of sensitivity to mechanical stress, flame and sparks, high water resistance and minimal physiological activity, not only in the composition of their emulsion, but also in by-products of the explosion. On the other hand, emulsion explosives can be phlegmatized, even completely desensitized, by a dynamic shock, especially by a strong wave of compressive stress caused by detonation of a charge located nearby in the rock. Another drawback is that only Category One safety explosives can be obtained from emulsion explosives. Both of these drawbacks are the result of relatively high brisance (i.e., crushing effect) of explosives of this type.

The most widespread principle of creating protective explosives for mining operations containing nitroesters is the use of cooling additives (most often sodium chloride) or cooling ion-exchange systems (for example, mixtures of ammonium chloride and sodium nitrate) in explosive mixtures. This leads to a decrease in the working capacity and brisance of the final explosive compared with nitroether explosives without cooling additives. However, as shown in the section "Examples of the implementation of the present invention", a similar introduction into the composition of sodium chloride in an amount up to 10% by weight of an emulsion explosive reduces its performance, while at the same time increasing brisance. Thus, the cooling effect of the aforementioned additives can be eliminated to a certain extent. The problem of brisance of emulsion explosives is, therefore, a determining factor in the creation of protective explosives for mining operations on this basis. In the existing literature, little attention is paid to the systematic study of the effect of brisance of emulsion explosives arising from the chemical composition of the components of the redox system of these explosives.

SUMMARY OF THE INVENTION

According to the method described in the present invention, the brisance of an emulsion explosive manufactured using reverse emulsion is modified by adding macromolecular components based on butadiene and isobutylene to the oil phase. The advantage of this method is that a relatively small amount of these added macromolecular components (0.5-1.8% by weight of the final explosive) significantly reduces brisance, while maintaining the performance of the emulsion explosive emulsion explosive, increasing its durability and modifying the consistency of the final explosive in such a way that when coolants are added to its composition, it becomes an explosive that falls into the first category in technology mining safety. Another advantage of the method described in the present invention is the easy availability of these macromolecular components, which are produced on an industrial scale for the needs of the production of plastics and rubbers, as well as for the production of special types of explosives.

The use of macromolecular components based on butadiene and isobutylene in accordance with the present invention has not previously been reported in the literature. It is described by the following examples, which in no way exclude possible changes in the order of use.

Examples of the implementation of the present invention

Example 1

A solution of ammonium nitrate (NA) or sodium nitrate (NN), and / or calcium nitrate (NK), and / or sodium perchlorate (PN), having a temperature of 85-100 ° C and which may contain other water-soluble components, such as chloride sodium (NaCl), glycol or the like, is fed into an emulsification apparatus containing a warm oil phase (80-85 ° C), which was intensively mixed (with a stirrer with a rotation speed of 1000-1500 rpm). This oil phase consists of mineral oil (having an average density of 910 kg / m ³ , a maximum solidification temperature of -5 ° C and a minimum flash point of 66 ° C) and / or paraffin wax (solidification temperature 39 ° C, flash point 220-260 ° C and an oil content of about 1.5% by weight), as well as sorbitan monooleate (M) and / or sorbitan sesquioleate (C) with the possible use of other macromolecular components. After the supply of an aqueous solution of salts is complete, the mixture should be mixed for more than 5 minutes. The emulsion matrix thus obtained is sensitized in a homogenizer by adding spherical silicon microparticles (MF) with an average size of 70 μm and can be modified by adding solid sodium chloride (NaCl) with an average grain size of 80 μm. The resulting explosive mixture is loaded into plastic tubes for the manufacture of charges weighing 400 g and a diameter of 32 mm. For each charge, the detonation velocity of the charge mass (D when using detonator No. 8) and relative operability (ORS) were determined. Summary data on the composition of individual mixtures prepared in accordance with this method are shown in the table together with the corresponding values of the average charge density, detonation velocity of the charge mass and relative performance.

The following macromolecular components were added to the oil phase:

- liquid polybutadiene rubber (PBG) having hydroxyl groups at the ends of the chain, with an average molar mass of 2400-3100, a polydispersity index of about 1.1 and a hydroxyl group content of about 0.7 mmol / g, in the macromolecule of which the number of structural units is [CH ₂ —CH = CH — CH ₂ ] - is about 44-57;

- a liquid isocyanate prepolymer (PBI - with tolylenisocyanate groups at the ends of the chain) with a polybutadiene main chain, having an average molar mass of 3200-3800, a polydispersity index of about 1.3 and a functionality of about 2.2, in the macromolecule of which the number of structural units is [CH ₂ -CH = CH-CH ₂ ] - is also approximately 44-57;

- solid copolymer polyisobutadiene (PIB) containing 2 mol%. isoprene, with an average molar mass of 200,000, having a common structural diagram

where m≫n.

In some emulsion mixtures containing PBI, in particular in mixtures 1.1, 1.3, and 1.4 from the table, a crosslinking catalyst was used. This led to the formation of plastic, well-formed matrices in which it was possible to introduce crystalline additives in an amount of up to 50% by weight without loss of cohesive strength of the final mixture. The mentioned macromolecular additives also increased the retention period of emulsion explosives (minimum 6 months) compared with explosives that do not contain such explosives (resistance 3-6 months).

Example 2

In accordance with Czechoslovak patent No. 229745 (1982), a solution of ammonium nitrate (HA) and sodium nitrate (HH), heated to a temperature of 80-90 ° C, was placed in an emulsification apparatus. A solution of oleic acid in mineral oil was supplied thereto, after which an aqueous solution of sodium hydroxide was supplied. The mixture was mixed until an emulsion formed. This emulsion was sensitized in a homogenizer by adding expanded perlite. The result was an emulsion explosive containing 62.9% by weight of HA, 13% NN, 12% water and 2.5% sodium hydroxide, 2.8% oil, 2.8% oleic acid and 4% expanded perlite; this explosive was registered under the name Emsit (Emsit). Its average density was 1.06 g / cm ³ , the detonation velocity D was 4817 m / s and the relative working capacity of the OPC was 69.5%.

Example 3

This example graphically illustrates the dependence of the relative health of the emulsion explosives from examples 1 and 2 on their brisance, represented by the product of the average charge density per square detonation velocity by the formula ρ * D ² . From this dependence it follows that the macromolecular components of the oil phase in Example 1 significantly reduce the brisance of the corresponding emulsion explosives compared to explosives in which these components are not used (including the Emsit from Example 2). This result is relevant for the explosive safety materials used in mining. This relationship, expressed graphically (see drawing), shows that in both groups of emulsion explosives, an increase in the amount of solid particles with a higher molar mass that they contain leads to a decrease in OPC and increases brisance (this is also true for the mineral content sensitizer).

Example 4

When detonating 1050 g of the explosive mixture from Example 1, given under 1.7 in the table, in the form of charges with a diameter of 32 mm, it did not ignite the methane-air mixture with a methane content of 9% or 1200 g of coal dust mixed with air when the dust concentration was 300 g / m ³ . It was found that the mass of the boundary charge for this explosive (in the form of a charge with a diameter of 32 mm) is 1241 ± 72 g. The gas products of its detonation did not contain nitrogen oxides.

Industrial applicability

The manufacture of an inverse emulsion suitable for the manufacture of an emulsion explosive with reduced crushing effect and retained biasing effect, for example, an explosive substance of high safety for mining.

Table Individual mix The composition of the individual mixtures (% by weight) Water ON NN NK Mon NaCl Gach Oil Polymer Glitz. Emulsifier MCH ρ (g / cm ³ ) D (m / s) ODP (%) 1.1 6.86 63.6 13,4 7.06 - - - 3.53 1.57 (PBI) - 1.96 (s) 1.96 1,181 3768.0 71.0 1.2 10.0 65.0 15,5 - - - - 3.9 0.6 (PIB) - 2.0 (s) 3.0 1,100 4186.0 67.0 1.3 6.2 58.3 - 24.85 - - - 3.3 1.55 (PBI) 0.97 1.94 (s) 2.9 1,067 4260.0 66.0 1.4 9.3 60.0 - 20.9 - - - 3.4 1.55 (PBI) - 1.94 (C) 2.9 1,090 4380,0 63.5 1.5 12,4 53.7 15,5 - - 9.3 3.2 - 0.7 (PBI) - 2.10 (C) 3,1 1,120 4456.0 61.5 1.6 10.0 57.3 15.0 - - 9.0 1,0 2.0 0.7 (PBI) - 2.0 (M) 3.0 1,150 4463.0 62.0 1.7 10.0 52.8 - 19.0 - 10.0 3.0 - 0.7 (PBI) - 2.0 (C) 2,5 1,202 4,376.0 61.5 1.8 10.0 58.0 15.0 - - 8.0 3.3 - 0.7 (PBI) - 2.0 (M) 3.0 1,150 4509.6 60.0 1.9 12,4 53.7 15,5 - - 9.3 3.2 - 0.7 (PBI) - 2.1 (M) 3,1 1,160 4567.0 60.5 1.10 9.0 60.0 14.2 - - 7.0 2.0 1,0 1.0 (PBG) - 1.8 (M) 4.0 1,130 4568.0 58.5 1.11 12.0 79.9 - - - - - 3,1 - - 2.0 (M) 3.0 1,031 4166.7 76.0 1.12 10.0 65.0 - - 15.7 - - 4.3 - - 2.0 (M) 3.0 1,055 4273.5 73.0 1.13 10.0 65.0 - 15,5 - - - 4,5 - - 2.0 (M) 3.0 1,085 4237.3 71.0 1.14 10.0 65.0 15,5 - - - - 4,5 - - 2.0 (M) 3.0 1,130 4385.0 70.5 Legend: ON - ammonium nitrate PBI - polybutadiene with isocyanate groups at the ends of the chain ρ is the average charge density NN - sodium nitrate PIB - polyisobutadiene D - detonation velocity NK - calcium nitrate PBG - polybutadiene with hydroxyl groups at the ends of the chain OPC - relative performance PN - sodium perchlorate C - sorbitan sesquioleate NaCl - Sodium Chloride M - sorbitan monooleate MCH - spherical microparticles of silicon

Claims (2)

1. A method for modifying the brisance of an emulsion explosive made using an inverse emulsion containing an oil phase and a dispersed phase consisting of an aqueous solution of inorganic nitrates and / or perchlorates, and it may also contain inorganic or organic components, including adding a brisance modifier to the oil phase characterized in that the modifier used brisance prepolymer or polymer having units - [CH ₂ -C (X) = CH-CH _2] -, wherein X - is H or -CH _3, in the macromolecule, to oraya ends or hydroxyl groups or isocyanate groups polyisobutylene in an amount of from 0.5 to 1.8% by weight of the emulsion explosive, the disperse phase which may contain cooling component in the form of an inorganic chloride group. 2. The method according to claim 1, characterized in that the brisance modifier is used in an amount of from 0.6 to 1.57% by weight of an emulsion explosive.