KR20010037469A - Energetic cartridged explosive emulsions - Google Patents

Abstract

PURPOSE: A cartridge-energetic emulsion explosive is provided, wherein the explosive is encased and sensitized in dispersed gas phase, is water-in-oil type, and is useful for exploding a soft rock. CONSTITUTION: The cartridge-energetic emulsion explosive comprises 60-70 wt% of ammonium nitrate; 8-14 wt% of sodium nitrate; 4-7 wt% of water; 0.5-5 wt% of hydrocarbon fuel; 0.5-5 wt% of an emulsifier; and 12-18 wt% of aluminum. The sum of ammonium nitrate and sodium nitrate is 70-80 wt%, and the sum of ammonium nitrate, sodium nitrate, water, hydrocarbon fuel, an emulsifier and aluminum is 95-100 wt%. Preferably the density is 1.26-1.40 g/cm¬2. The hydrocarbon fuel is selected from the group consisting of an oil, a wax, paraffin and their mixtures; and the emulsifier is selected from the group consisting of an amine, a fatty acid ester, an alkylaryl sulfonate, a polymer containing both hydrophilic chains and hydrophobic chains and their mixtures.

Description

Energetic cartridged explosive emulsions

The present invention relates to the general field of industrial explosives for civil use.

The present invention relates to a novel cartridge explosive emulsion that is particularly suitable for blasting hard rock in a quarry or workshop.

Water-in-oil type cartridge explosive emulsions are well known in the art.

These include, as a component, a discontinuous aqueous phase in the form of droplets of an aqueous inorganic oxide salt solution;

A water-insoluble continuous organic phase in which the droplets described above are dispersed;

Emulsifiers forming an emulsion of aqueous droplets throughout the continuous organic phase;

And a discontinuous gas phase uniformly dispersed in the emulsion, which increases the sensitivity of the emulsion to each ignition bubble of the dispersion gas that acts as a hot portion.

Compared with conventional dynamite containing 25% to 45% nitroglycerin, the explosive emulsions described above are safe to use and their preparation is greatly improved. On the other hand, they are less powerful and emit lower explosion energy.

Those skilled in the art will appreciate the safety and ignition sensitization of the known cartridge explosive emulsions and the force of dynamite (i.e. the explosion rate in the area measured at a limit diameter of 80 mm is 6000 m / s, Explosive emulsions of the type described above, all with energy greater than approximately 1100 cal / g), have long been developed.

It is known to increase the density of explosives to increase the explosion rate. However, in the case of cartridge explosive emulsions sensitized by a dispersed gas phase, an increase in density accompanied with a decrease in the volume content of the gas phase reduces the sensitization to ignition.

Sensitization molecules (such as hydrazine nitrite and organic nitrates), in particular amine nitrates (such as methylamine nitrate), or another reaction catalyst (such as copper chloride), or highly reactive oxidants (such as Reduced sensitization by introducing chlorate or perchlorate).

However, the use of such stabilizing molecules, catalysts and / or reactive oxidants presents a potential risk of spark accidents. For this reason, organic nitrates, chlorates and perchlorates are particularly dangerous to handle, hydrazine nitrates are unstable, and metal catalysts can be used in combination with ammonium nitrate, inorganic oxide salts, which are always used in the composition alone or as a mixture with other oxide salts. Because it can react.

EP patent application 598,115, for example, describes a strong explosive emulsion of ammonium nitrate, which contains amine nitrate and / or hydrazine nitrate as sensitizer.

US Pat. No. 4,371,408 describes explosive emulsions based on ammonium nitrate and sodium nitrate which are sensitized by amine nitrates containing CuCl ₂ as the explosion catalyst.

In addition, means for introducing aluminum into explosive emulsions to increase energy are known. However, the increase in aluminum content is practically limited in that the energy yield (which is the ratio of measured energy to calculated theoretical energy) is greatly reduced.

Moreover, it is known that when the aluminum content increases, the explosion rate decreases because the mass content of the gaseous products in the decomposition product is reduced.

Based on these teachings and these findings, it would seem that one of ordinary skill in the art would not be able to obtain an emulsion having all of the desired properties and characteristics described above.

However, these expectations have been overcome.

Especially unexpectedly, in the absence of inorganic salts other than ammonium nitrate and sodium nitrate, sensitizing molecules (such as organic nitrates or hydrazine nitrates) and metal catalysts, ammonium nitrate and sodium nitrate are combined in specific amounts and the properties of the other components. And carefully selected content, especially water and aluminum content, the performance characteristics of conventional dynamite, i.e. an explosion rate in the area measured at a limit diameter of 80 mm with an energy yield of more than 80%, measured in water It has been found that explosive emulsions with ignition sensitization and safety of use and manufacturing of standard cartridge explosive emulsions can be obtained at the same time that the total energy exceeds 1100 cal / g (may exceed 1200 cal / g).

Accordingly, the subject of the present invention is a novel cartridge explosive emulsion of water-in-oil type, comprising ammonium nitrate, sodium nitrate, water, hydrocarbon-based fuels, emulsifiers and aluminum, and sensitized by a dispersed gas phase.

These new explosive emulsions have an ammonium nitrate content of 60% to 70% by weight;

The content of sodium nitrate is 8 wt% to 14 wt%;

The water content is 4% to 7% by weight;

The content of the hydrocarbon fuel is 1% by weight to 4% by weight;

The content of emulsifier is 0.5% to 4% by weight;

The content of aluminum is 12 wt% to 18 wt%;

The total content of ammonium nitrate and sodium nitrate is 70% by weight to 80% by weight;

The total content of ammonium nitrate, sodium nitrate, water, hydrocarbon fuels, emulsifiers and aluminum is 95% to 100% by weight, preferably 98% to 100% by weight, more preferably 99% to 100% by weight. It features.

The above-mentioned weight content is indicated for the sensitized explosive emulsion and it should be understood that the above range is included.

The novel explosive emulsions described above according to the invention are in particular chlorates and perchlorates of ammonium, alkali metals or alkaline-earth metals, sensitizing molecules such as organic nitrates such as alkylamine nitrates and alkanolamines. Nitrate), or hydrazine nitrates such as hydrazine nitrate and methylhydrazine nitrate, and metallic reaction catalysts such as copper chloride.

In addition, the hydrocarbon-based fuel may be a mixture of several hydrocarbon-based fuels, and the emulsifier may be a mixture of several emulsifiers.

Hydrocarbon-based fuels may be aliphatic, cycloaliphatic or aromatic and may be saturated or unsaturated. For example, toluene, xylene, petroleum spirits, kerosene, fuel oils, paraffins, oils, in particular paraffin oils or naphthalene oils, fatty acids and derivatives thereof, waxes and mixtures thereof, ie any mixtures of two or more of the compounds mentioned above can do.

The hydrocarbon-based fuel is preferably selected from the group consisting of oils, waxes and paraffins and mixtures thereof.

Emulsifiers can be any emulsifier known in the art to promote the physical stability of water-in-oil emulsions by lowering the surface tension between the two phases of the emulsion.

Emulsifiers are preferably hydrophilic and hydrophobic chains (e.g. derivatives of polyisobutylene and succinic anhydrides), in particular amines having 12 to 24 carbon atoms, fatty acid esters (e.g. sorbitan monooleate, sorbitan laurate, sorbitan) Palmitate and sorbitan stearate), alkylaryl sulfonates, and mixtures thereof.

The aluminum used in the present invention is finely divided and is preferably powder.

Its particle size is generally from 0.1 μm to 250 μm, more preferably from 0.5 μm to 150 μm.

Explosive emulsions according to the invention are sensitized by a dispersed gas phase according to methods known in the art.

The most well known methods for introducing the gas phase into explosive emulsions include porous materials, such as glass or plastic microballoons, styrene foam, which contain mechanical mixing, release of the gas itself by chemicals, and closed pore openings. The introduction of pearls, or fly ashes, may be mentioned. It is also possible to combine various methods, for example the simultaneous use of chemicals and centroids.

According to the invention, preference is given to using the release of the gas itself by chemicals, in particular by nitrite, such as sodium nitrite, which reacts with the ammonium ions of ammonium nitrate to increase the formation of nitrogen itself. This reaction can be promoted by an increase in temperature and / or by a catalyst (eg urea, thiourea or thiocyanate).

In a particularly preferred manner, the explosive emulsions according to the invention contain from 13% to 17% by volume of the dispersed gas phase, more preferably from 14% by volume to 16% by volume of the dispersed gas phase.

According to one preferred variant of the invention, the total content of ammonium nitrate and sodium nitrate is 73% to 77% by weight, more preferably 74% to 76% by weight.

According to another preferred variant, the content of ammonium nitrate is 61% to 67% by weight, more preferably 62% to 65% by weight.

According to another preferred variant, the content of water is 4.5% to 6.5% by weight, more preferably 5% to 6% by weight.

According to another preferred variant, the content of aluminum is from 13% to 17% by weight, more preferably from 13.5% to 16.5% and most preferably from 14% to 16% by weight.

According to another preferred variant, the content of emulsifier is from 1.5% to 4% by weight, more preferably from 2% to 3.5% by weight.

According to another preferred variant, the content of hydrocarbon-based fuel is from 0.7% to 4% by weight, more preferably from 0.8% to 3% by weight and most preferably from 1% to 2% by weight.

Furthermore, the density of the explosive emulsion according to the invention is preferably 1.26 to 1.40, more preferably 1.28 to 1.37, and the explosion speed measured at a limit diameter of 80 mm is 5500 m / s to 6300 m / s, more preferably 5750 m. / s to 6300 m / s, and the actual total energy measured in water is 1100 cal / g to 1400 cal / g, more preferably 1200 cal / g to 1400 cal / g.

Explosive emulsions according to the present invention include any of the known waterborne oil type explosive emulsions, including ammonium nitrate, sodium nitrate, water, hydrocarbon-based fuels, emulsifiers and aluminum, and sensitized by a dispersed gas phase. Similar to the method can be obtained.

For example, in the first step, (1) an aqueous phase can be prepared by dissolving ammonium nitrate and sodium nitrate in water at a temperature of, for example, 100 ° C. to 105 ° C. in a tank equipped with a heating system and a stirring system.

In the case of chemical vaporization, the above-mentioned reaction catalysts such as urea, thiourea or thiocyanate can optionally be added at this stage to the aqueous phase.

(2) By mixing the components together, for example in a temperature range of 95 ° C., it is possible to produce a fatty phase consisting of hydrocarbon-based fuels and generally emulsifiers, for example in a tank equipped with a heating system and a stirring system.

In addition, the emulsifier may not be introduced into the hydrocarbon fuel at this stage.

In a second step, the water-in-oil emulsion is then prepared in a continuous or batch process.

According to the batch method, if the required amounts of aqueous phase, fatty phase and emulsifier are introduced into the blender and then this is not introduced into the fat phase, the emulsion is obtained using a turbomixer and at the same time using, for example, a clover paddle. Can be homogenized.

According to the continuous method, two phases and emulsifiers are pumped using a metering pump in the feed pipe of the emulsifying machine, if not introduced into the fat phase.

The various auxiliaries used, ie aluminum, chemical gas generators and / or centroids are then introduced in the third step to the obtained emulsion.

According to the batch method, aluminum, centroids and / or chemical gas generators are preferably introduced into the emulsion by blending in the blender used for the preparation of the emulsion or by blending in the blender with irregular stirring.

According to the continuous process, the auxiliaries are preferably introduced continuously, for example using endless screws, into the mixer from which the oil-in-water emulsion flows out.

The sensitized explosive emulsions thus prepared are then optionally cooled first and then sheathed (e.g., paper or plastic sheath) using cartridge-loading devices known to those of ordinary skill in the art. Load manually or automatically).

The cartridge obtained is then generally stabilized in cold water or cold air, for example depending on the nature of the sheath, to stabilize the final product obtained.

The following non-limiting examples illustrate the invention and the advantages provided thereby.

Examples 1 and 2: explosive emulsions according to the invention

An explosive emulsion having the following weight composition is prepared.

Example 1 Example 2 Ammonium Nitrate Sodium Nitrate Water Hydrocarbon Fuel Emulsifier with Chemical Reaction Catalyst (Tiourea) Chemical Gas Generator (Sodium Nitrite) 63.1% 11.7% 5.6% 1.4% 3.1% 15.0% ≤0.1% 63.6% 11.8% 5.7% 1.1% 2.7% 15.0% ≤0.1%

Example 1

a) preparation of an aqueous phase

74.3 parts by weight of ammonium nitrate, 13.8 parts by weight of sodium nitrate and 0.04 parts by weight of thiourea are dissolved in 6.6 parts by weight of water in a tank equipped with a heating system and a stirring system at a temperature of 100 ° C to 105 ° C.

b) preparation of fatty phases

3.7 parts by weight of an emulsifier consisting of each 40/60 mixture of a sorbitan monooleate and a polyisobutylene chain whose hydrophilic ends are attached via succinic anhydride functionality;

A hydrocarbon fuel consisting of a 10/35/20/35 mixture of naphthenic mineral oils with a flash point above 100 ° C., solid paraffins with a melting point above 50 ° C., liquid paraffins with a flash point above 150 ° C., and microcrystalline waxes with a melting point above 50 ° C. The 1.6 parts by weight mixture is homogenized at 95 ° C. in another tank equipped with a heating system and a stirring system.

c) preparation of emulsions and addition of auxiliaries

Subsequently, the aqueous phase (a) and the fat phase (b) are introduced into the blender, and then the emulsion is prepared by a turbomixer while homogenizing the mixture using a clover paddle. The temperature of the blender is auto-maintained between 105 ° C and 110 ° C.

After obtaining a homogeneous stable emulsion, 17.7 parts by weight of aluminum powder having a particle size of 0 to 150 탆 (average diameter about 80 탆) was added and the temperature was maintained while stirring, followed by 0.09 parts by weight of sodium nitrite prior to the cartridge-loading step. Add.

d) loading explosive emulsion into the cartridge;

Subsequently, the explosive emulsion obtained in step (c), which is kept at temperature, is loaded into a cartridge in a plastic sheath cut at both ends, thereby obtaining, for example, a substantially cylindrical cartridge of about 320 mm in length and about 80 mm in diameter.

The mass of explosive emulsion introduced into each sheath is clearly estimated from the volume of the desired cartridge, the density of the explosive emulsion measured before loading into the cartridge, and the desired volume content of the gas phase (about 15%). do.

If the explosive emulsion contained in the enclosure occupies all of the volume provided by the cartridge, after reaching the desired volume content of the gas phase, the chemical reaction for the formation of nitrogen stops by rapidly lowering the temperature of the emulsion, which is a cold water cartridge. It is easily achieved by spraying.

Example 2

This method is performed in the same manner as in Example 1, with the following differences:

a) preparation of an aqueous phase

74.9 parts of ammonium nitrate (instead of 74.3 parts), 13.9 parts of sodium nitrate (instead of 13.8 parts) and 6.7 parts of water (instead of 6.6 parts) are used.

b) preparation of fatty phases

3.2 parts by weight (instead of 3.7 parts by weight) of emulsifier and 1.3 parts by weight of hydrocarbon fuel (instead of 1.6 parts by weight) are used.

Physical and explosive properties of explosive emulsions obtained according to conventional methods known to those skilled in the art are as follows:

Example 1 Example 2 Theoretical energy 1470cal / g 1480cal / g Total energy measured in water 1203cal / g 1225cal / g Energy yield (measured energy / theoretical energy) 0.82 0.83 Content of gas (volume) 14.8% 14.9% Measured density 1.32 1.32 Induction of all explosives (lead nitride initiator) 0.5g 0.5g Explosion rate measured on steel with 80 mm diameter 5800 m / s 5900 m / s Impact sensitization (30 kg impact hammer) 〉 1200J 〉 1200J

The explosive emulsions according to the invention not only possess the energy and strength of dynamite, but also exhibit excellent use safety and manufacturing safety, and are particularly suitable for blasting hard rocks.

Claims (10)

The ammonium nitrate content is 60% to 70% by weight; The content of sodium nitrate is 8 wt% to 14 wt%; The water content is 4% to 7% by weight; The content of the hydrocarbon fuel is 0.5% by weight to 5% by weight; The content of emulsifier is 0.5% to 5% by weight; The content of aluminum is 12 wt% to 18 wt%; The total content of ammonium nitrate and sodium nitrate is 70% by weight to 80% by weight; Ammonium nitrate, sodium nitrate, water, hydrocarbon-based fuels, emulsifiers and aluminum, characterized in that the total content of ammonium nitrate, sodium nitrate, water, hydrocarbon fuels, emulsifiers and aluminum is 95% to 100% by weight Cartridge explosive emulsion of water-in-oil type sensitized by gas phase. The explosive emulsion according to claim 1, wherein the content of water is 5% by weight to 6% by weight. The explosive emulsion according to claim 1 or 2, wherein the content of aluminum is 13.5 wt% to 16.5 wt%. The explosive emulsion according to claim 1, wherein the total content of ammonium nitrate and sodium nitrate is 73% by weight to 77% by weight. The explosive emulsion of claim 1 wherein the density is from 1.26 to 1.40. The explosive emulsion of claim 1 wherein the explosion speed measured at a limit diameter of 80 mm is between 5500 m / s and 6300 m / s. The explosive emulsion according to claim 1, wherein the substantial total energy measured in water is from 1100 cal / g to 1400 cal / g. The explosive emulsion according to claim 1, wherein the dispersed gas phase content is 13 vol% to 17 vol%. The explosive emulsion of claim 1 wherein the hydrocarbon-based fuel is selected from the group consisting of oils, waxes, paraffins and mixtures thereof. The explosive emulsion of claim 1 wherein the emulsifier is selected from the group consisting of polymers comprising amines, fatty acid esters, alkylaryl sulfonates, hydrophilic chains and hydrophobic chains and mixtures thereof.