Patent Application
20240391848
The present disclosure relates to an emulsion explosive composition for a booster for a bulk explosive.
At the present time, pentolite, which is mainly used as a booster of a bulk explosives, is prepared by melting and mixing TNT, which is a high explosive, and pentaerythritol tetranitrate (PETN). Pentolite has the advantage of high detonation velocity (PETN and TNT, detonation velocity=8,000 m/s or higher) due to the high explosives contained therein. On the other hand, due to the nature of high explosives used as raw materials, pentolite has the disadvantage of accidental explosion by the surrounding environmental conditions (impact, friction, static electricity, etc.) due to its high sensitivity. In addition, since pentolite is a solid phase, it can be broken by external impacts and thus should be handled with care.
The ingredients, TNT and PETN, of pentolite have the problem of decomposing under certain conditions. TNT decomposes in each of the following conditions: alkali hydrolysis, pyrolysis, biodegradation, and PETN decomposes by reaction with a metal and by metabolism of a microorganism or strain. This decomposition may result in a deterioration of the performance of pentolite or an accidental explosion by the decomposition reaction.
Another problem may be the melting point of the pentolite. That is, TNT, which is an ingredient of the pentolite, has a melting point of about 80° C. However, some blasting sites may have a high temperature. Therefore, the use of pentolite is prohibited on high-temperature ground sites with 60° C. or higher.
An emulsion explosive was introduced as a booster that can resolve the above disadvantages of the pentolite. This emulsion explosive used as a booster has advantages in that it can be used on high-temperature ground, is not easily damaged by impacts, and is free from accidental explosion attributable to external environmental conditions. However, the emulsion explosive has the disadvantage of lower detonation velocity than a solid-phase booster. Therefore, there is a need for ways to improve the detonation velocity.
Korean Patent Application Publication No. 10-2008-0083920 “Water-in-oil Emulsion Explosive” (published as of Sep. 19, 2008) is a related art of the present disclosure.
The present disclosure has been made to solve the aforementioned problems, and an objective of the present disclosure is to provide an emulsion explosive composition for a booster of a bulk explosive, the composition being capable of use on high-temperature ground, being not damaged by impacts, and being free from accidental explosion attributable to external environmental conditions.
The present disclosure provides an emulsion explosive composition for a booster of a bulk explosive, the composition including 88% to 98% by weight of an oxidizer aqueous solution, 0.1% to 6% by weight of an emulsifier, 0.1% to 5% by weight of fuel oil, and 0.1% to 1.0% by weight of plastic micro balloons (PMB).
The oxidizer aqueous solution is an oxidizer aqueous solution containing ammonium nitrate, sodium nitrate, calcium nitrate, water, and at least one selected from monomethyl amine nitrate (MMAN) and ethylene diamine dinitrate (EDDN).
The emulsion prepared has a particle size in the range of 0.5 μm to 2.0 μm.
The emulsion explosive composition for a booster of a bulk explosive, according to the present disclosure, is an emulsion-based explosive having a particle size of 2 μm or less and providing a level of detonation velocity that maximizes the explosive power of the bulk explosive. In addition, the emulsion explosive composition of the present disclosure has an advantage of being capable of use in a high-temperature reactive ground, being free from damage by impacts, and of preventing accidental detonation attributable to an external environmental condition.
Hereinafter, the present disclosure will be described in detail.
The present disclosure relates to an emulsion explosive composition for a booster of a bulk explosive, the composition including 88% to 98% by weight of an oxidizer aqueous solution, 0.1% to 6% by weight of an emulsifier, 0.1% to 5% by weight of fuel oil, and 0.1% to 1.0% by weight of plastic micro balloons (PMB).
The oxidizer aqueous solution is an oxidizer aqueous solution containing ammonium nitrate, sodium nitrate, calcium nitrate, water, and at least one selected from monomethyl amine nitrate (MMAN) and ethylene diamine dinitrate (EDDN).
The emulsion prepared has a particle size in the range of 0.5 μm to 2.0 μm.
A conventional emulsion explosive composition for a booster is advantageous over a solid-phase booster (for example, pentolite) in that emulsion explosive composition can be used on a high-temperature ground, is not easily damaged by impacts, and is free from accidental explosion attributable external environmental conditions. However, the emulsion explosive composition has the disadvantage of lower detonation velocity than a solid-phase booster.
The present disclosure is characterized by improving the detonation velocity by adjusting the emulsion particle size of the emulsion explosive to be 2 μm or less.
The emulsion may have a particle size in the range of 0.5 μm to 2 μm. When preparing an emulsion having a particle size of less than 0.5 μm, since the shear required in the manufacturing process is extremely high, it is difficult to manage the process conditions. When the particle size is larger than 2 μm, it is not desirable because the detonation velocity is low.
In one embodiment of the present disclosure, the emulsion explosive composition comprises 88% to 98% by weight of an oxidizer aqueous solution, 0.1% to 6% by weight of an emulsifier, 0.1% to 5% by weight of a fuel oil, and 0.1% to 1% by weight of PMB, relative to the total weight thereof.
When the proportion of the oxidizer aqueous solution is outside the range, it is difficult to form an emulsion. When the proportion is excessively low, non-detonation may occur. When the content of the emulsifier falls outside of the above range, an emulsion may not be formed, or non-detonation may occur. When the content of the fuel oil falls outside of the above range, an emulsion may not be formed, or non-detonation may occur.
In one embodiment of the present disclosure, the oxidizer aqueous solution includes 2% to 15% by weight of one or more selected from among monomethyl amine nitrate (MMAN) and ethylene diamine dinitrate (EDDN), 65% to 94% by weight of ammonium nitrate, 2% to 15% by weight of sodium nitrate, 1% to 10% by weight of calcium nitrate, and 1% to 10% by weight of water. At least one selected from among MMAN and EDDN included in the oxidizer aqueous solution is used in an amount of 3% to 10% by weight with respect to the total weight of the emulsion explosive composition.
In one embodiment of the present disclosure, the emulsifier may use one or more selected from the group consisting of Sorbitan mono oleate (SMO) and amine salt of polyisobutylenesuccinicanhydride but is not limited thereto.
In one embodiment of the present disclosure, the fuel oil may be one or more selected from the group consisting of wax, mineral oil, light oil, and liquid paraffin.
In one embodiment of the disclosure, the PMB is used as a foam retaining agent. The bubbling agent is a component that forms a space in the gunpowder with the use of air or a gas and which serves as a sensitizer. The PMB may be a copolymer of vinyldienechloride (VDC), methylmethacrylate (MMA), and acrylonitrile (ACN) or may be selected from polymers of ACN. When the content of ACN in the copolymer is 50% by weight or less, the chemical resistance may be lower than required. Therefore, it is preferable that the copolymer contains the ACN in an amount of 50% by weight or more.
When the PMB content is less than 0.1% by weight or more than 1% by weight, it is not desirable because the ballistic mortar or detonation velocity is reduced and uncomplete detonation may occur. The PMB has a true specific gravity (d) of 0.02 to 0.1 g/cc and an average particle size of 20 to 100 μm for the role of a hot spot (maintaining continuous explosion by adiabatic compression) when used as a foam retaining agent.
Herein below, the present disclosure will be described in more detail with reference to examples described below. The examples are intended to describe the present disclosure in more detail but the scope of the present disclosure is not limited by the examples. A number of changes may be made to the following examples without departing from the scope of the present disclosure.
An emulsion was prepared by emulsifying a mixture of 93% by weight of a 100° C. oxidizer aqueous solution and 7% by weight of a 90° C. fuel solution, in which the oxidizer aqueous solution was composed of 10% by weight of MMAN, 70% by weight of ammonium nitrate, 10% by weight of sodium nitrate, 5% by weight of calcium nitrate, and 5% by weight of water, and the fuel solution was composed of 3% by weight of light oil and 4% by weight of an emulsifier. An emulsion explosive was prepared by mixing 99.8% by weight of the emulsion and 0.2% by weight of PMB (a copolymer of ACN, MMA, and DVC including 50% of ACN of 50%, true specific gravity (d)=0.02) using a mixer.
An emulsion was prepared by emulsifying a mixture consisting of 93% by weight of an oxidizer aqueous solution having the same composition as the oxidizer aqueous solution used in Example 1, and 7% by weight of a 90° C. fuel solution including 3% by weight of wax and 4% by weight of an emulsifier. An emulsion explosive was prepared by mixing 99.8% by weight of the emulsion and 0.2% by weight of PMB using a mixer.
An emulsion having the same composition as in Example 1 was prepared. An emulsion explosive was prepared by mixing 99.74% by weight of the emulsion and 0.26% by weight of PMB using a mixer.
An emulsion having the same composition as in Example 2 was prepared. An emulsion explosive was prepared by mixing 99.74% by weight of the emulsion and 0.26% by weight of PMB using a mixer.
An emulsion was prepared by emulsifying a mixture consisting of 93% by weight of an oxidizer aqueous solution having the same composition as the oxidizer aqueous solution used in Example 1, and 7% by weight of a 90° C. fuel solution including 3% by weight of liquid paraffin and 4% by weight of an emulsifier. An emulsion explosive was prepared by mixing 99.7% by weight of the emulsion and 0.3% by weight of PMB using a mixer.
An emulsion was prepared by emulsifying a mixture consisting of 94% by weight of an oxidizer aqueous solution having the same composition as the oxidizer aqueous solution used in Example 1, and 6% by weight of a 90° C. fuel solution including 3% by weight of liquid paraffin and 3% by weight of an emulsifier, by using a homogenizer. An emulsion explosive was prepared by mixing 99.7% by weight of the emulsion and 0.3% by weight of PMB using a mixer.
An emulsion was prepared by emulsifying a mixture consisting of 94.5% by weight of an oxidizer aqueous solution having the same composition as the oxidizer aqueous solution used in Example 1, and 5.5% by weight of a 90° C. fuel solution including 3% by weight of liquid paraffin and 2.5% by weight of an emulsifier, by using a homogenizer. An emulsion explosive was prepared by mixing 99.67% by weight of the emulsion and 0.33% by weight of PMB using a mixer.
An emulsion having the same composition as in Example 1 was prepared. After adding 98.4% by weight of the emulsion and 1.6% by weight of GMB (3M, Glass Micro Bubble K-15), an emulsion explosive was prepared using a flash mixer.
Emulsion explosives with different emulsion particle sizes were prepared by adjusting the emulsification rate and emulsification time of the emulsion of Example 1, and the emulsion explosives with different emulsion particle sizes were compared in terms of detonation velocity. The particle sizes of the emulsions were measured using a measuring device (Mastersizer), and the detonation velocity was evaluated by a test in which each emulsion explosive was confined in a Φ50 mm steel pipe. The same test was also performed on the emulsion explosive of Comparative Example 1. The sizes of the prepared emulsions are as shown in Table 1 below, and the detonation velocity evaluation results are shown in
As illustrated in
indicates data missing or illegible when filed
Experimental Example 2: Evaluation of Performance of Emulsion Explosive Comparative testing was conducted in mine field conditions for the comparison between pentolite, which is a solid booster conventionally used, and the emulsion explosive of the present disclosure (manufactured as in Example 5). That is, an explosion test was performed using pentolite and the emulsion explosive of the present disclosure (prepared as in Example 5) at a site where ANFO and HiMEX 75-120 are used as a bulk explosive, in a D89 mm hole, the detonation velocity was measured. In the same site and conditions, the test was performed with 150 g and 200 g of pentolite and 150 g, 200 g, 230 g, and 300 g of the emulsion explosive as a booster (prepared in Example 5). The test results are shown in Table 2 below.
The results of Table 2 show that the detonation velocities of bulk explosives were similar regardless of the type of booster. The results mean that the emulsion explosive of the present exhibits similar performance compared to pentolite, which is a solid booster, even though the explosive composition of the present disclosure is an emulsion-type booster.
Emulsion explosives as boosters need to be usable both in low and high temperature environments. Thus, the emulsion explosive of Example 7 was used to evaluate the usability in low and high temperature environments. In the case of the low temperature environment, the test was conducted at a low temperature of −20° C., which is a typical low evaluation temperature for testing explosives. In the case of the high temperature environment, no clear standard was established. Therefore, after storing the explosive at a temperature of 100° C. for more than 2 hours, the change in performance was measured through the test. The evaluation results are shown in Table 3 below.
The above test results confirmed that the emulsion explosive as a booster according to the present disclosure exhibited a detonation velocity allowing the use in both a low-temperature environment and a high-temperature environment.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0174698 | Dec 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/015125 | 10/7/2022 | WO |
