EMULSION EXPLOSIVE COMPOSITION FOR BOOSTER OF BULK EXPLOSIVE

Abstract

The present disclosure provides an emulsion explosive composition for a booster of a bulk explosive. The composition contains 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 prepared emulsion has a particle size in the range of 0.5 m to 2.0 m.

Claims

1. An emulsion explosive composition for a booster of a bulk explosive, the composition comprising 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), wherein the oxidizer aqueous solution is an oxidizer aqueous solution comprising ammonium nitrate, sodium nitrate, calcium nitrate, water, and at least one selected from monomethyl amine nitrate (MMAN) and ethylene diamine dinitrate (EDDN), and a prepared emulsion has a particle size in the range of 0.5 m to 2.0 m.

2. The composition of claim 1, wherein MMAN or EDDN contained in the oxidizer aqueous solution is contained in an amount of 3% to 10% by weight respect to the total weight of the emulsion explosive composition.

3. The composition of claim 1, wherein the PMB is a copolymer of vinyldienechloride (VDC), methylmethacrylate (MMA), and acrylonitrile (ACN) or comprises one or more selected from polymers of ACN.

4. The composition of claim 1, wherein the emulsifier is one or more selected from the group consisting of sorbitan mono oleate (SMO) and an amine salt of polyisobutylenesuccinicanhydride (PIBSA).

5. The composition of claim 1, wherein the fuel oil is one or more selected from the group consisting of wax, mineral oil, light oil, and liquid paraffin.

Description

DESCRIPTION OF DRAWINGS

[0012] FIG. 1 is a graph showing a correlation between the particle size of an emulsion in an emulsion explosive and the detonation velocity when PMB is applied, the correlation being confirmed through Experimental Example 1.

[0013] FIG. 2 is a graph showing a correlation between the particle size of an emulsion in an emulsion explosive and the detonation velocity when GMB is applied, the correlation being confirmed through in Experimental Example 1.

BEST MODE

[0014] Hereinafter, the present disclosure will be described in detail.

[0015] 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).

[0016] 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).

[0017] The emulsion prepared has a particle size in the range of 0.5 m to 2.0 m.

[0018] 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.

[0019] The present disclosure is characterized by improving the detonation velocity by adjusting the emulsion particle size of the emulsion explosive to be 2 m or less.

[0020] The emulsion may have a particle size in the range of 0.5 m to 2 m. When preparing an emulsion having a particle size of less than 0.5 m, 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 m, it is not desirable because the detonation velocity is low.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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 m for the role of a hot spot (maintaining continuous explosion by adiabatic compression) when used as a foam retaining agent.

[0028] 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.

Example 1

[0029] 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.

Example 2

[0030] 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.

Example 3

[0031] 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.

Example 4

[0032] 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.

Example 5

[0033] 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.

Example 6

[0034] 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.

Example 7

[0035] 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.

Comparative Example 1

[0036] 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.

Experimental Example 1: Evaluation of Detonation Velocity According to Particle Size of Emulsion

[0037] 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 50 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 FIGS. 1 and 2.

[0038] As illustrated in FIG. 1, when PMB was used, the emulsion explosives exhibited similar detonation velocities regardless of the emulsion particle size. On the other hand, as illustrated in FIG. 2, when GMB was used, there was a tendency that the detonation velocity decreased as the emulsion particle size increased. To reduce the variations caused by the manufacturing conditions, it is preferable to use PMB.

TABLE-US-00001 TABLE 1 Emulsion particle Average Classificati size detonation Example 1 0.74 6108 0.92 6246 1.07 5925 1.78 6172 Comparative 0.74 6338 Example 1 1.13 6211 1.54 5917 1.78 5945 indicates data missing or illegible when filed

[0039] 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.

TABLE-US-00002 TABLE 2 Booster Detonation Bulk Type of Dosage velocity (m/s) product booster (g) Ave. Range ANFO Pentolite 150 3771 3667~3836 200 3429 2145~3868 as booster 150 2801 2013~3588 Emulsion 200 3475 3470~3480 explosive 230 3383 2121~3902 (prepared in 300 3370 2072~3828 Example 5) HiMEX Pentolite 150 4893 4452~5334 75-120 200 5405 5092~5691 as booster 150 5125 Emulsion 200 5247 5040~5485 explosive 230 5454 (prepared in 300 5159 4737~5424 Example 5)

[0040] 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.

Experimental Example 3

[0041] 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.

TABLE-US-00003 TABLE 3 Detonation Classification Conditions velocity (m/s) Room 50 mm 6,466 temperature confined Room 50 mm 6,292 temperature confined Low 5,920 Temperature High 5,700 Temperature

[0042] 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.