AU2022283709B2 - Emulsion explosive composition for booster of bulk explosive - Google Patents

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 pm to 2.0 pm.

Description

DESCRIPTION EMULSION EXPLOSIVE COMPOSITION FOR BOOSTER OF BULK EXPLOSIVE

Technical Field

The present disclosure relates to an emulsion explosive

composition for a booster for a bulk explosive.

Background Art

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 600C 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

September 19, 2008) is a related art of the present

disclosure.

Each document, reference, patent application or patent

cited in this text is expressly incorporated herein in their entirety by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application or patent cited in this text is not repeated in this text is merely for reasons of conciseness.

Throughout the specification, unless the context

requires otherwise, the word "comprise" or variations such

as "comprises" or "comprising", will be understood to imply

the inclusion of a stated integer or group of integers but

not the exclusion of any other integer or group of integers.

Furthermore, throughout the specification, unless the

context requires otherwise, the word "include" or variations

such as "includes" or "including", will be understood to

imply the inclusion of a stated integer or group of integers

but not the exclusion of any other integer or group of

integers.

Disclosure Technical Problem In accordance with an aspect of the present invention,

there is provided 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), a prepared emulsion has a particle size in the range of

0.5 pm to 2.0 pm; and

wherein the prepared emulsion has average detonation

velocity 5,925 m/s or more without containing a solid

booster.

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.

Technical Solution

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

3a 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 pm to 2.0 pm.

3b

Advantageous Effects

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 pm 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.

Description of Drawings

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.

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

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 pm to 2.0 pm.

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 pm or less.

The emulsion may have a particle size in the range of 0.5

pm to 2 pm. When preparing an emulsion having a particle size of less than 0.5 pm, 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 pm, 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 pm 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.

Example 1.

An emulsion was prepared by emulsifying a mixture of 93%

by weight of a 1000C oxidizer aqueous solution and 7% by weight

of a 900C 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.

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 900C 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.

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.

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.

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 900C 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.

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 900C 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.

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.

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

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 050 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.

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 1] Classificati Emulsion particle size Average detonation 0.74 6108 0.92 6246 1.07 5925 Example 1 1.78 6172 0.74 6338 1.13 6211 Comparative 1.54 5917

Example 1 1.78 5945

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 089 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 2]

Type of BoosterT Bulk booster DosagerI Detonation velocity (m/s) booster Dosage productI Ave. Range

Pentolite 150 3771 3667 to 3836

200 3429 2145 to 3868

as booster Emulsion 150 2801 2013 to 3588 ANFO explosive

200 3475 3470 to 3480

230 3383 2121 to 3902

300 3370 2072 to 3828

Pentolite 150 4893 4452 to 5334

200 5405 5092 to 5691

HiMEX 75- as booster 120 Emulsion 150 5125 explosive

200 5247 5040 to 5485

230 5454

300 5159 4737 to 5424

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.

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

1000C for more than 2 hours, the change in performance was

measured through the test. The evaluation results are shown in

Table 3 below.

[Table 3] Classificati , Detonation Conditions on velocity (m/s) Room 050 mm confined 6,466 temperature Room 6,292 temperature t50 mm confined Low 5,920 Temperature

High 5,700 Temperature

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.

Claims (5)

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),

a prepared emulsion has a particle size in the range of 0.5

pm to 2.0 pm, and

wherein the prepared emulsion has average detonation

velocity 5,925 m/s or more without containing a solid booster.

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.