CN113831204A - Lithium borohydride sensitized emulsion explosive - Google Patents

Abstract

The invention discloses a lithium borohydride sensitized emulsion explosive, which relates to the technical field of explosive preparation. Its components include a hydrogen storage sensitizer and an emulsifying matrix; In its solution form, the emulsion explosive includes the following raw materials by weight: 0.01-6wt% of hydrogen storage sensitizer, and 94.00-99.99wt% of emulsifying matrix. The lithium borohydride solution is prepared by uniformly dissolving lithium borohydride in an aqueous solution or an alkaline solution, the pH value of the alkaline solution is between 7-14, and the density of the emulsion explosive can be adjusted according to the needs of the sensitizer. The content of lithium borohydride in the solution is between 1-500g/L. The sensitizer lithium borohydride powder or solution added in the present invention is evenly distributed in the emulsification matrix, releases hydrogen through the hydrolysis reaction and diffuses in the emulsification matrix to form micro-bubbles, and the hydrogen bubbles not only play a sensitizing "hot spot" in the emulsion explosive It also acts as an energetic material to participate in the detonation reaction of the explosive, which increases the output energy of the emulsion explosive.

Description

Lithium borohydride sensitized emulsion explosive

Technical Field

The invention relates to the technical field of explosive preparation, in particular to an emulsion explosive sensitized by lithium borohydride or a solution thereof.

Background

The development of the emulsion explosive in China is at the end of the 60's in the 20 th century, and the emulsion explosive generally refers to water-in-oil (W/O) emulsion type water-resistant industrial explosive produced by adopting an emulsion technology. Because of having excellent water-resistant, environmental protection, explosion and storage performances, the explosive is widely applied and is also one of the civil industrial explosives with the highest use ratio at present. The components are that the fine droplets of oxidant aqueous solution (prepared by dissolving ammonium nitrate, sodium sulfate and the like in water) are used as a dispersed phase, a very thin oil film with higher strength (namely an oil phase material which also acts as a reducing agent) is coated outside the dispersed phase, the dispersed phase has higher viscosity, and a special water-in-oil type emulsification system is formed, and the special water-in-oil type emulsification system is called as an emulsification matrix (also called as an emulsion matrix). The emulsion matrix is an unsensitized emulsion explosive, does not have detonator sensitivity, has high density, needs high initiation energy and is very difficult to transfer explosion. Therefore, the last important step in the preparation of emulsion explosives is the sensitization process. The emulsion matrix is sensitized by adding a sensitizer through a physical or chemical method, namely, a large number of uniformly distributed micro-bubbles are introduced into the emulsion matrix, the detonation sensitivity of the detonator is generated by utilizing the adiabatic compression and the 'hot spot' characteristic of air in the bubbles, and the emulsion matrix becomes the emulsion explosive after the sensitization process is finished. The sensitizer of the traditional industrial emulsion explosive is divided into a physical sensitizer, a chemical sensitizer and a composite sensitizer (two substances of the physical sensitizer and the chemical sensitizer are added in sequence according to a proportion), wherein the common physical sensitizer comprises hollow glass microspheres and expanded perlite, and the chemical sensitizer comprises ammonium nitrite. It should be noted that, in the prior art, whether a physical sensitizer is used or a foaming agent added in chemical sensitization is used, the sensitization process mainly introduces a large amount of uniformly distributed micro bubbles to play a role in increasing 'hot spots' in an emulsion matrix, so that the emulsion explosive has detonator initiation sensitivity, and the traditional sensitizer material plays a role in 'hot spots' only, is not an energetic material and does not contribute to the explosion and detonation energy of the emulsion explosive.

The hydrogen storage material is a novel energetic material, is added into an emulsion matrix as a sensitizing agent, and can release hydrogen under certain conditions. Hydrogen has higher energy density, which is three times higher than that of liquid hydrocarbon fuel; and when the catalyst acts with oxygen, the only product is water, and no pollution is generated. The hydrogen gas released by sensitization reaction in the emulsion matrix can be used as a sensitization hot spot of the emulsion explosive, and the hydrogen gas is also an energetic material, so that the energy of the emulsion explosive can be improved in the explosion and detonation processes of the emulsion explosive. Lithium borohydride is a new hydrogen storage material, have the characteristic of storing the hydrogen density large, hydrogen dynamic property is good, its hydrogen storage mass ratio reaches 19.26%, and have the advantage that the overall quality is light, the resource is abundant, the price is cheap.

According to Chinese patent search, the patent application named as 'titanium hydride type hydrogen storage emulsion explosive' has the following application numbers: CN201110277487.4, publication number: CN102432408A, the method is that high-purity titanium hydride hydrogen storage material with the mass of 0.6-8% is added into the emulsion explosive, during the detonation process, the titanium hydride is used as a sensitizing agent to generate chemical reaction with water in the emulsion matrix, a small amount of hydrogen is released, and a certain sensitizing effect is achieved on the emulsion matrix. Patent application entitled "magnesium hydride type hydrogen storage emulsion explosive", application number: CN201110277355.1, publication number: CN102432407A, the method is that high-purity magnesium hydride hydrogen storage material with the mass of 0.2-6% is added into the emulsion explosive, the magnesium hydride is used as a sensitizing agent to carry out chemical reaction with water in the emulsion matrix, a small amount of hydrogen is released, and a certain sensitizing effect is achieved on the emulsion matrix. The name of the patent application is 'methane storage type glass microsphere sensitized emulsion explosive and a preparation method thereof', the application number is as follows: CN201710862489.7, publication number: CN107573201A, the method is that methane gas is stored in glass microspheres through a continuous ventilation device to form a methane storage type glass microsphere sensitizing agent, the methane storage type glass microsphere sensitizing agent is added into an emulsion matrix for sensitization according to the mass ratio of 1.5-3.5, and an emulsion explosive is obtained, and the sensitizing agent plays a role in sensitizing and also plays a role in improving explosion energy and the content of gas of explosion products. The name of the patent application is 'ethane storage type glass microsphere sensitized emulsion explosive', and the application number is as follows: CN201710875003.3, publication number: CN107473915A, the method is that ethane gas is stored in glass microspheres through a continuous ventilation device to form an ethane storage type glass microsphere sensitizing agent, the ethane storage type glass microsphere sensitizing agent is added into an emulsion matrix for sensitization according to the mass ratio of 1.5-3.5, and an emulsion explosive is obtained, and the sensitizing agent plays a role in sensitizing and also plays a role in improving explosion energy and the content of gas of an explosion product. The name of the patent application is 'a physical hydrogen storage glass microsphere sensitized emulsion explosive and a preparation method thereof', the application number is as follows: CN202011399319.8, publication number: CN112479793A, the method is to store free hydrogen in glass microspheres as an energy-containing sensitizer of the emulsion explosive, and the energy-containing sensitizer not only provides an energy-containing hot spot, but also obviously improves the detonation performance of the explosive.

It can be seen from the above patents that titanium hydride and magnesium hydride are used as sensitizing agents in emulsion explosives, which belong to chemical sensitization methods, and have the advantages of small hydrogen release amount, low sensitization efficiency, and expensive materials, thereby greatly increasing the cost of industrial emulsion explosives, and being not suitable for large-scale production and application of emulsion explosives. After storing free hydrogen, methane and ethane in the glass microspheres, the glass microspheres are applied to emulsion explosives as physical sensitizers, and since gas storage needs to be completed in a high-temperature high-pressure reaction kettle, the process is complex, the cost of the glass microspheres is high, the time and the economic cost can be further increased by gas storage, large-scale low-cost production is difficult to realize, and the sensitizers cannot meet the requirement of industrial emulsion explosive mass production. As a novel hydrogen storage sensitizer, the lithium borohydride has the advantages of stable hydrogen storage inside the material, good hydrogen release dynamic performance and low price, and can meet the requirement of large-scale production of emulsion explosives. The method is characterized in that lithium borohydride is independently added into an emulsion matrix in a form of powder or solution as a sensitizing agent, the lithium borohydride completes the hydrogen releasing process in the emulsion matrix through conventional uniform stirring, the sensitizing process of the emulsion explosive is realized, released tiny hydrogen bubbles are not only initiation 'hot spots' of the emulsion explosive but also energetic substances in explosive explosion, and the detonation performance of the emulsion explosive is improved on the premise of ensuring the initiation sensitivity of the emulsion explosive.

Disclosure of Invention

The invention aims to provide a lithium borohydride sensitized emulsion explosive, which adopts lithium borohydride as a sensitizing agent, and the lithium borohydride is added into an emulsion matrix in the form of powder or solution to complete the sensitization process of the emulsion explosive. The mechanism of sensitization is specifically illustrated as follows: the lithium borohydride and water in the emulsion matrix are subjected to hydrolysis reaction to release tiny hydrogen bubbles, and the hydrogen bubbles play dual roles of detonating 'hot spots' and energetic working media, so that the explosive has excellent detonation performance, the sensitizer is low in cost and small in unit mass explosive, and the cost of the industrial emulsion explosive is greatly reduced.

The invention adopts the following technical scheme for realizing the purpose:

a lithium borohydride sensitized emulsion explosive comprises the components of a hydrogen storage sensitizer and an emulsion matrix; the hydrogen storage sensitizer is in a form of lithium borohydride or a solution thereof, and the emulsion explosive comprises the following raw materials in percentage by weight: 0.01-6 wt% of hydrogen storage sensitizer and 94.00-99.99 wt% of emulsifying base material.

Further, the lithium borohydride is white powder, in order to improve the sensitization speed and the sensitization efficiency, the contact area of the sensitizer and the emulsifying matrix is increased, and the lithium borohydride is ground into fine powder, so that the effect is better.

Further, the lithium borohydride solution is prepared by uniformly dissolving lithium borohydride in an aqueous solution or an alkaline solution, wherein the aqueous solution can be distilled water or purified water; the alkaline solution has pH of 7-14, and is prepared by dissolving sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium carbonate, silver diammine hydroxide, ammonia water (monohydrate ammonia), lithium hydroxide, barium hydroxide, calcium hydroxide, sodium hydroxide, potassium hydroxide, etc. in distilled water or purified water at a certain ratio.

Furthermore, the mass of the lithium borohydride in the aqueous solution and the alkaline solution is 1-500g/L, and the content of the lithium borohydride in the sensitizer solution can be adjusted according to the density of the emulsion explosive required to be prepared.

Furthermore, the formula of the emulsion matrix is the same as that of the emulsion matrix commonly used in the existing emulsion explosive, and the emulsion matrix is generally composed of ammonium nitrate, sodium nitrate, calcium nitrate, sodium sulfate, urea, water, wax, rosin, sorbitol monooleate, an emulsifier and the like.

Further, the preparation method of the lithium borohydride sensitized emulsion explosive is the same as the preparation method of adding the physical sensitizer glass microspheres in the prior art, lithium borohydride powder is added into an emulsion matrix or lithium borohydride solution is added in a titration mode, then a stirrer is used for continuous stirring, the mixture is uniformly mixed, and the mixture is placed for more than 3 hours to complete the preparation.

The invention has the beneficial effects that:

1. the added lithium borohydride crystal powder or solution is uniformly distributed in the emulsified matrix, the added lithium borohydride and a small amount of combined water in the emulsified matrix are subjected to hydrolysis reaction to generate hydrogen, the released hydrogen is wrapped by the emulsified matrix and is diffused in the emulsified matrix to form micro bubbles, so that a certain foaming effect is achieved on the emulsified matrix, and finally a hot spot of initiation and explosion propagation is formed, so that the emulsified matrix is sensitized to have detonator sensitivity and become the emulsified explosive.

2. The added lithium borohydride sensitizer generates hydrogen bubbles in the emulsion matrix, and because hydrogen is a high-energy gas substance, a large amount of energy can be released after combustion, hydrogen microbubbles generated by hydrolysis reaction play a role in sensitizing hot spots in the emulsion explosive, and participate in the reaction on a detonation wave front in the detonation reaction of the emulsion explosive to provide energy output. Therefore, the output energy of the lithium borohydride sensitized emulsion explosive comprises the energy released by the emulsion matrix and the lithium borohydride together, the hydrogen participates in the reaction to change the energy output structure of the emulsion explosive, and the total output energy of the type of the explosive is larger than that of the existing emulsion explosive.

3. The invention uses lithium borohydride powder or solution thereof as a novel sensitizing agent, compared with the emulsion explosive formed by adding physical sensitizing agent glass microspheres in the prior art, the emulsion explosive meets the explosion performance standard of industrial explosives on explosion mechanical parameters such as shock wave peak value, impulse, energy and the like, and is a novel emulsion explosive with excellent performance. And the price of the lithium borohydride is much cheaper than that of the glass microspheres, so that the cost of the industrial emulsion explosive is reduced from the production material, and the lithium borohydride can be well applied to large-scale industrial production.

Drawings

FIG. 1 is a shock wave curve diagram obtained by an underwater explosion test of the hydrogen storage emulsion explosive containing 0.4% of lithium borohydride in example 1 of the present invention.

FIG. 2 is a shock wave curve diagram obtained by an underwater explosion test of the emulsion explosive containing 4% of glass microspheres in example 1 of the present invention.

FIG. 3 is a shock wave curve diagram obtained by an underwater explosion test of the hydrogen storage emulsion explosive containing 0.8% of lithium borohydride in example 2 of the present invention.

FIG. 4 is a shock wave curve diagram obtained by an underwater explosion test of the emulsion explosive containing 0.25% of sodium nitrite in example 2 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the total mass of lithium borohydride and the emulsifying matrix is 30g, and the content of lithium borohydride is 0.4 percent of the total mass (0.12 g). And adding lithium borohydride powder into the emulsified substrate at normal temperature, continuously stirring for 30-60 minutes by using a stirrer, and carrying out underwater explosion test after standing for 3 hours.

The formulation of the emulsifying base used is shown in table 1:

table 1 emulsion base formulation used in example 1

For comparative experiments, the control group was sensitized by adding glass microspheres, a conventional physical sensitizer, to the emulsion matrix. Experiments have shown that: when the content of the glass microspheres is 4%, the output energy of the emulsion explosive is the maximum. Therefore, in the production of this example, the total mass of the emulsion base and the glass microspheres was 30g, and the content of the glass microspheres was 4% of the total mass (═ 1.2 g). The kind of the emulsifying base used was the same as in Table 1. After adding the glass microspheres to the emulsified base, the mixture was continuously stirred for 45 minutes using a stirrer, and then left for 3 hours to perform an underwater explosion test.

In the underwater explosion test, the shock wave curve of the emulsion explosive with the content of lithium borohydride being 0.4 percent of the total mass of the emulsion explosive is shown in figure 1, and the shock wave curve of the emulsion explosive with the content of glass microspheres being 4 percent of the total mass of the emulsion explosive is shown in figure 2. In the figure: the abscissa represents time (unit: us), the ordinate represents pressure (unit: MPa), and the underwater explosion shock wave curve is recorded by an oscilloscope. The various test parameters are shown in table 2, and the data in table 2 are read from the shock wave curves.

Table 2 example 1 detonation parameters for underwater explosive shock waves

As can be seen from Table 2, the peak pressure of the lithium borohydride type hydrogen storage emulsion explosive is smaller than that of an emulsion explosive of glass microspheres, but the impulse and the energy density are both larger than those of the emulsion explosive of glass microspheres, the energy density is the explosion heat released after each kilogram of the emulsion explosive is exploded, and the energy density is calculated through specific impact wave energy and specific bubble energy in underwater explosion experimental tests. Namely, although the lithium borohydride reduces the shock wave peak pressure of the underwater explosion of the emulsion explosive, the sensitized hot spot hydrogen bubbles participate in the detonation wave front reaction, so that the temperature and the duration of an explosion field can be increased, and the damage effect of the emulsion explosive is improved.

Example 2:

the total mass of lithium borohydride and the emulsifying matrix is 30g, and the content of lithium borohydride is 0.8 percent of the total mass (0.24 g). And adding lithium borohydride powder into the emulsified substrate at normal temperature, continuously stirring for 30-60 minutes by using a stirrer, and carrying out underwater explosion test after standing for 3 hours.

The formulation of the emulsifying base used is shown in table 3:

table 3 emulsion base formulation used in example 2

For comparative experiments, the control group was sensitized by adding the traditional chemosensitizer sodium nitrite to the emulsion matrix. Experiments have shown that: when the content of the sodium nitrite is 0.15-0.4%, the output energy of the emulsion explosive is the maximum. Therefore, in the preparation of this example, the total mass of the emulsion base and sodium nitrite was 30g, and the sodium nitrite content was 0.25% of the total mass (═ 0.075 g). The kind of the emulsifying base used was the same as in Table 1. After adding sodium nitrite to the emulsified base, the mixture was continuously stirred for 30 minutes using a stirrer, and then placed in a 50 ℃ incubator for 3 hours, followed by underwater explosion test.

In the underwater explosion test, the shock wave curve of the emulsion explosive with the content of lithium borohydride being 0.8 percent of the total mass of the emulsion explosive is shown in figure 3, and the shock wave curve of the emulsion explosive with the content of sodium nitrite being 0.25 percent of the total mass of the emulsion explosive is shown in figure 4. In the figure: the abscissa represents time (unit: us), the ordinate represents pressure (unit: MPa), and the underwater explosion shock wave curve is recorded by an oscilloscope. The various test parameters are shown in Table 4, and the data in Table 4 are read from the shock wave curves.

Table 4 example 2 detonation parameters for underwater explosive shock waves

As can be seen from Table 4, the peak pressure of the lithium borohydride type hydrogen storage emulsion explosive is smaller than that of an emulsion explosive of glass microspheres, but the impulse and the energy density are both larger than those of the emulsion explosive of glass microspheres, the energy density is the explosion heat released after each kilogram of the emulsion explosive is exploded, and the energy density is calculated through specific impact wave energy and specific bubble energy in underwater explosion experimental tests. In the lithium borohydride type emulsion explosive, sensitized hot spot hydrogen bubbles participate in detonation wavefront reaction, and the released gas of the sodium nitrite sensitized emulsion explosive is inert gas nitrogen, so that in comparison, the hydrogen hot spot can be used as the sensitized bubbles and can also be used as an energetic working medium to participate in detonation reaction, and although the lithium borohydride reduces the shock wave peak pressure of underwater explosion of the emulsion explosive, the sensitized hot spot hydrogen bubbles participate in detonation wavefront reaction, so that the temperature and the duration time of an explosion field can be improved, and the positive effect on improving the damage effect of the emulsion explosive is achieved.

It will be evident to those skilled in the art that the invention/inventions are not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention/invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (6)

1. a lithium borohydride sensitized emulsion explosive, characterized in that its component comprises a hydrogen storage sensitizer and an emulsifying matrix, and the hydrogen storage sensitizer is lithium borohydride or its solution form, and the emulsion explosive The raw materials in the following weight percentages are included: 0.01-6 wt % of hydrogen storage sensitizer, and 94.00-99.99 wt % of emulsifying matrix. 2. The hydrogen storage sensitizer lithium borohydride according to claim 1, wherein the lithium borohydride is a white powder, and in order to improve the sensitization speed and the sensitization efficiency, the contact between the sensitizer and the emulsification matrix is increased. area, it is better to grind lithium borohydride into fine powder. 3. The hydrogen storage sensitizer lithium borohydride solution according to claim 1, wherein the lithium borohydride solution is made by uniformly dissolving lithium borohydride in an aqueous solution or an alkaline solution, and the aqueous solution can be distilled water Or purified water; the pH value of the alkaline solution is between 7-14, consisting of sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium carbonate, silver diammine hydroxide, ammonia water (ammonia monohydrate), hydrogen Lithium oxide, barium hydroxide, calcium hydroxide, sodium hydroxide, potassium hydroxide, etc. are dissolved in distilled water or purified water in a certain proportion. 4. hydrogen storage sensitizer lithium borohydride solution according to claim 1, is characterized in that, the quality of described lithium borohydride in aqueous solution and alkaline solution is between 1-500g/L, as required The density of the emulsion explosive can be adjusted to adjust the content of lithium borohydride in the sensitizer solution. 5. emulsifying base according to claim 1 is characterized in that, the formula of described emulsifying base is identical with the formula of emulsifying base commonly used in existing emulsion explosives, and emulsifying base generally has ammonium nitrate, sodium nitrate, calcium nitrate, sodium sulfate , urea, water, wax, rosin, sorbitol monooleate, emulsifier and other components. 6. lithium borohydride sensitized emulsion explosive according to claim 1, is characterized in that, the preparation method of described lithium borohydride sensitized emulsion explosive and the method of adding physical sensitizer glass microspheres in the prior art The preparation method is the same. After adding lithium borohydride powder or titrating lithium borohydride solution to the emulsified matrix, use a stirrer to continuously stir to make the mixing uniform, and then stand for more than 3 hours to complete.

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