EMULSION EXPLOSIVE COMPOSITION AND PREPARATION METHOD THEREFOR

Abstract

The present invention relates to an emulsion composition for an explosive and to a method of preparing the same, wherein the emulsion composition includes, based on the total weight thereof, 85 to 95 wt % of an oxidizing agent aqueous solution, 0.3 to 5 wt % of an emulsifier, and 3 to 10 wt % of oil, the emulsifier including a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65, under a precondition that the oxidizing agent aqueous solution includes at least one of industrial ammonium nitrate, agricultural ammonium nitrate and low-specific-gravity ammonium nitrate for an ammonium nitrate fuel oil explosive, which is used without additional filtration or removal of impurities.

Description

TECHNICAL FIELD

The present invention relates to an emulsion composition for an emulsion explosive, in which stability is ensured when granular ammonium nitrate including an organic or inorganic material is provided in the form of an oxidizing agent aqueous solution using water, without an additional filtration process, and to a method of preparing the same.

BACKGROUND ART

In bulk emulsion explosives, which are currently used as industrial explosives at mining sites for metals, coal, limestone and the like worldwide, including Korea, an ammonium-nitrate-based oxidizing agent has been utilized. Specifically, an emulsion explosive is produced by preparing a liquid oxidizing agent through the synthesis of nitric acid and ammonia in a plant for manufacturing a liquid oxidizing agent, which is separately constructed. When the liquid oxidizing agent thus synthesized is used, a pure ammonium nitrate oxidizing agent may be obtained, and the prepared emulsion is advantageous because the stability thereof may be ensured for about 3 months or more, as required by the consumer, but investment costs are undesirably increased due to the need to construct a separate plant for producing a liquid oxidizing agent. Therefore, in order to minimize the cost of constructing a plant for producing liquid ammonium nitrate, a method of purchasing and dissolving solid ammonium nitrate has been employed as an alternative, but is problematic because ammonium nitrate, having high purity, is solidified due to chemical properties that facilitate absorption of moisture during storage, and thus a crusher has to be additionally used.

In order to ensure handling convenience, moreover, granular ammonium nitrate including a solidification inhibitor is produced and sold in the form of, depending on the end use thereof, agricultural ammonium nitrate, porous ammonium nitrate for ammonium nitrate fuel oil explosives, high-specific-gravity ammonium nitrate, etc. However, in order to prepare an emulsion, in the case in which such ammonium nitrate is used in the form of an oxidizing agent aqueous solution by dissolving the same in water, the emulsion cannot be formed or the emulsion stability may deteriorate due to the solidification inhibitor and the additional organic or inorganic material. With the goal of solving these problems, the emulsion is typically prepared using an oxidizing agent aqueous solution resulting from filtering and removing impurities other than the ammonium nitrate, but problems such as the cost of disposal of the removed impurities, the increased risk due to handling of materials at high temperatures, and lowered productivity due to additional processing may occur.

Meanwhile, Korean Patent Application Publication No. 10-2005-0074279 discloses a waterproof granular explosive composition (Laid-open date: Jul. 18, 2005), comprising porous ammonium nitrate, a nitro compound and the like, whereby the explosive composition is easy to handle, is easily manufactured, and has sufficient water resistance and explosion performance for a typical immersion time upon practical use, but is difficult to apply to an emulsion explosive composition.

DISCLOSURE

Technical Problem

Accordingly, the present invention has been made keeping in mind the problems encountered in the related art, and an objective of the present invention is to provide an emulsion composition for an emulsion explosive, having high storage stability, in which, in order to exhibit stability effects suitable for use in industrial emulsion explosives, ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate, is used, without an additional filtration or removal process, in the form of a disperse-phase aqueous solution in a water-in-oil emulsion, together with a polyisobutylene succinic anhydride (PIBSA) amine salt emulsifier having an acid value of 30 or less and an amine value of 45 to 65, and a method of preparing the same.

Technical Solution

The present invention provides an emulsion composition for an explosive, comprising an oxidizing agent aqueous solution including ammonium nitrate; and a fuel solution including an emulsifier and fuel oil, in which the emulsifier includes a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65.

In addition, the present invention provides a method of preparing an emulsion composition for an explosive, the method comprising: preparing an oxidizing agent aqueous solution including ammonium nitrate at 50 to 95° C.; and preparing an emulsion by emulsifying the oxidizing agent aqueous solution at 50° C. to 95° C. using a fuel solution including an emulsifier and fuel oil, without removal of impurities other than the ammonium nitrate through additional filtration, in which the emulsifier includes a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65.

Advantageous Effects

According to the present invention, an emulsion composition for an emulsion explosive can be manufactured at low cost and can exhibit superior stability compared to conventional emulsions for emulsion explosives. In particular, the emulsion composition for an emulsion explosive according to the present invention can manifest superior long-term storage stability and mixing stability, and also, material costs can be desirably reduced by about 12% by virtue of the use of ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate having a price, on average, of about 80% compared to conventional liquid ammonium nitrate.

MODE FOR INVENTION

Hereinafter, a detailed description will be given of the present invention.

A preferred embodiment of the present invention is specified below with reference to the appended drawings. Before the detailed description of the present invention, it must be noted that the terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions. Therefore, the embodiments described in the present specification and the constructions shown in the drawings are merely preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention, and thus it is to be understood that a variety of equivalents and modifications able to substitute therefor may be provided at the point in time at which the present invention is filed.

The present invention pertains to an emulsion composition for an emulsion explosive, comprising an oxidizing agent aqueous solution including ammonium nitrate and a fuel solution including an emulsifier and fuel oil, and to a method of preparing the same, in which a significant improvement in stability has been experimentally confirmed when ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate, is used together with an emulsifier having a specific amine value and acid value, thus culminating in the present invention.

The ammonium nitrate may include, as granular ammonium nitrate, at least one of agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive and high-specific-gravity ammonium nitrate, and an organic or inorganic material.

The organic or inorganic material may include, for example, a phase-transition inhibitor, a solidification inhibitor, a coating agent, and the like, and is exemplified by at least one of a phase-transition inhibitor, a solidification inhibitor, and a coating agent.

More specifically, the organic or inorganic material may include at least one selected from among magnesium nitrate, silicate, clay, aluminum sulfate, diatomaceous earth, talc, and an amine salt.

Specifically, the emulsion composition for an emulsion explosive according to the present invention includes an oxidizing agent aqueous solution including ammonium nitrate and a fuel solution including an emulsifier and fuel oil, in which the emulsifier includes a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65.

The emulsion composition for an explosive according to the present invention is described in detail below.

Ammonium Nitrate

The ammonium nitrate used in the oxidizing agent aqueous solution of the emulsion composition for an explosive is ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate.

The three kinds of ammonium nitrate above are classified based on the following characteristics.

Agricultural ammonium nitrate is UN No. 2067 Ammonium Nitrate Fertilizer 5.1, and is configured such that ammonium nitrate contains an inorganic material or a chemical material. Here, 90% or more of ammonium nitrate and 0.2 wt % or less of a combustible material are included.

Porous ammonium nitrate for an ammonium nitrate fuel oil explosive and high-specific-gravity ammonium nitrate are classified as the same group of UN No. 1942. Specifically, porous ammonium nitrate is configured such that granular ammonium nitrate is formed with pores and thus has a bulk density of less than 0.9 g/cc, and high-specific-gravity ammonium nitrate is granular ammonium nitrate having no pores and thus has a bulk density of 0.95 g/cc or more.

Oxidizing Agent Aqueous Solution

The oxidizing agent aqueous solution may be composed of an oxidizing agent and water, and the oxidizing agent essentially contains ammonium nitrate. In particular, the ammonium nitrate used in the oxidizing agent aqueous solution of the present invention is preferably ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate, and more preferably is used without an additional filtration or removal process.

The oxidizing agent may further include at least one selected from the group consisting of sodium nitrate and calcium nitrate.

The oxidizing agent aqueous solution preferably includes 75 to 85 wt % of the oxidizing agent and 15 to 25 wt % of water, in order to ensure booster explosiveness. If the amount of water is less than 15 wt %, the power of an explosive may increase, thus making it impossible to realize booster explosiveness, and also, the crystallization temperature of the oxidizing agent aqueous solution is elevated, thus deteriorating the stability of the emulsion. On the other hand, if the amount of water exceeds 25 wt %, the sensitivity of the explosive may decrease, thus lowering explosiveness. Hence, these amounts preferably fall in the above weight ranges in order to attain an explosive having bulk emulsion explosive properties.

Fuel Solution

The fuel solution may include an emulsifier and fuel oil.

The emulsifier of the present invention mainly includes a PIBSA (polyisobutylene succinic anhydride) amine salt. Here, SMO (sorbitan monooleate) may be used in an amount of 20 wt % or less based on the total weight of the emulsifier.

In the present invention, to enable the use of ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate, without an additional filtration or removal process, 100 wt % of a PIBSA (polyisobutylene succinic anhydride) amine salt is preferably used as an emulsifier. For the purpose of sensitizing an emulsion through a chemical reaction or of reducing material costs, SMO (sorbitan monooleate) may be added in a small amount, but is preferably used in an amount of 20 wt % or less based on the total weight of the emulsifier. If the amount of SMO exceeds 20 wt %, storage stability after emulsion preparation may be insufficient and thus the emulsion may break down when mixed with a material such as a sensitizer and an ammonium nitrate fuel oil explosive or during emulsion storage, whereby the oxidizing agent may precipitate and the emulsion may undesirably become nonexplosive.

Moreover, in the present invention, the PIBSA amine salt emulsifier may be any example thereof having an acid value of 30 or less and an amine value of 45 or more. If the acid value exceeds 30 or if the amine value is less than 45 under the condition that the acid value is 30 or less, the emulsion cannot be formed, or even when the emulsion is formed, the stability thereof may deteriorate, whereby the oxidizing agent undesirably precipitates during storage. Most preferably, a PIBSA amine salt emulsifier having chemical properties of an acid value of 30 or less and an amine value of 45 to 65 is used in the present invention. If these values fall out of the above ranges, the long-term storage stability and mixing stability of the prepared emulsion composition for an explosive may drastically deteriorate, which is undesirable.

The fuel oil may be at least one selected from the group consisting of mineral oil and light oil. In an explosive phase, convenience in use and long-term stability may be improved through the use of continuous-phase oil (fuel), which is exposed to the outside and comes into contact with air. Light oil or mineral oil, which is a constituent of the oil, is liquid at room temperature and remains in an appropriate explosive phase when combined at a suitable ratio with the emulsifier, thus providing convenience in use and increasing long-term storage stability.

The fuel solution preferably includes, based on the total weight thereof, 2 to 35 wt % of the emulsifier and 65 to 98 wt % of the fuel oil. If the amount of the emulsifier falls out of the above range, the emulsion may not be formed or an explosion may not occur. If the amount of the fuel oil falls out of the above range, the emulsion may not be formed or an explosion may not occur.

In the present invention, the oxidizing agent aqueous solution and the fuel solution are mixed together, thus forming an emulsion solution. Here, the emulsion composition preferably includes, based on the total weight thereof, 85 to 95 wt % of the oxidizing agent aqueous solution including the ammonium nitrate and 5 to 15 wt % of the fuel solution including the emulsifier and the fuel oil, which are mixed together. If the amount of the oxidizing agent aqueous solution falls out of the above range, the power of the resulting explosive is high and thus booster explosiveness necessary for a bulk emulsion explosive may not be realized. If the amount thereof is small, an explosion may not occur.

The emulsion of the present invention preferably has a bulk density of 1.20 to 1.50 g/cc, which is determined by the weight ratio of ammonium nitrate and water or the weight ratio of potassium nitrate or calcium nitrate that is additionally added.

Moreover, when the viscosity of the emulsion is high in manufacturing and blasting fields, problems related to transport or mixing with other materials may occur. Hence, the emulsion preferably has a viscosity of 40,000 or less. To this end, the emulsifier has to be used within the above amount range. If the amount of the emulsifier is high, the viscosity may increase and manufacturing costs may also be increased.

In addition, the present invention pertains to a method of preparing an emulsion composition for an explosive, the method comprising: preparing an oxidizing agent aqueous solution including ammonium nitrate without additional filtration or removal of impurities; and preparing an emulsion by emulsifying the oxidizing agent aqueous solution using a fuel solution including an emulsifier and fuel oil.

In the method of preparing the emulsion composition for an explosive according to the present invention, for the description of the oxidizing agent aqueous solution and the fuel solution, reference may be made to the above description of the emulsion composition for an explosive.

Specifically, the method of preparing the emulsion composition for an explosive according to the present invention includes preparing an oxidizing agent aqueous solution including ammonium nitrate at 50° C. to 95° C. and preparing an emulsion by emulsifying the oxidizing agent aqueous solution at 50° C. to 95° C. using a fuel solution including an emulsifier and fuel oil, without removal of impurities other than the ammonium nitrate through additional filtration, in which the emulsifier includes a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65.

The emulsifier may further include SMO (sorbitan monooleate), the amount of which is preferably 20 wt % or less based on the total weight of the emulsifier. If the amount of SMO exceeds 20 wt %, storage stability is insufficient after emulsion preparation, and thus the emulsion may break down when mixed with a material such as a sensitizer and ammonium nitrate fuel oil explosive or during emulsion storage, whereby the oxidizing agent may precipitate and the emulsion may undesirably become nonexplosive.

A better understanding of the present invention will be given through the following Examples, which are merely set forth to illustrate the present invention but are not to be construed as limiting the scope of the present invention. The following Examples may be appropriately modified or altered by those skilled in the art within the scope of the present invention.

Example 1

An emulsion was prepared by emulsifying 93 wt % of an oxidizing agent aqueous solution at 80° C. comprising 80 wt % of ammonium nitrate and 20 wt % of water and 7 wt % of a fuel solution at 70° C. comprising 71 wt % of light oil and 29 wt % of a PIBSA amine salt emulsifier using an emulsifying machine.

Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 50 and an acid value of 8.

Example 2

An emulsion was prepared using the composition in the same wt % as in Example 1. Here, the PIBSA amine salt emulsifier that was used upon emulsion preparation was an emulsifier having an amine value of 63 and an acid value of 24.

Example 3

An emulsion was prepared by emulsifying 93 wt % of the same oxidizing agent aqueous solution as in Example 1 and 7 wt % of a fuel solution at 70° C. comprising 79 wt % of mineral oil and 21 wt % of a PIBSA amine salt emulsifier using an emulsifying machine. Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 50 and an acid value of 8.

Example 4

An emulsion was prepared by emulsifying 93 wt % of the same oxidizing agent aqueous solution as in Example 1 and 7 wt % of a fuel solution at 70° C. comprising 79 wt % of mineral oil, 18 wt % of a PIBSA amine salt emulsifier and 3 wt % of an SMO emulsifier using an emulsifying machine. Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 50 and an acid value of 8.

Example 5

An emulsion was prepared by emulsifying 91.5 wt % of an oxidizing agent aqueous solution at 80° C. comprising 50 wt % of ammonium nitrate, 30 wt % of calcium nitrate and 20 wt % of water and 8.5 wt % of a fuel solution at 70° C. comprising 94 wt % of mineral oil and 6 wt % of a PIBSA amine salt emulsifier using an emulsifying machine. Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 50 and an acid value of 8.

Comparative Example 1

An emulsion solution was prepared using the composition in the same wt % as in Example 1. Here, the PIBSA amine salt emulsifier that was used for the emulsion solution was an emulsifier having an amine value of 15 and an acid value of 22.

Comparative Example 2

An emulsion was prepared by emulsifying 93 wt % of the same oxidizing agent aqueous solution as in Example 1 and 7 wt % of a fuel solution at 70° C. comprising 79 wt % of mineral oil, 14 wt % of a PIBSA amine salt emulsifier and 7 wt % of an SMO emulsifier using an emulsifying machine. Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 50 and an acid value of 8.

Comparative Example 3

An emulsion solution was prepared using the composition in the same wt % as in Example 5. Here, the PIBSA amine salt emulsifier that was used for the emulsion solution was an emulsifier having an amine value of 15 and an acid value of 22.

Comparative Example 4

An emulsion was prepared by emulsifying 93 wt % of the same oxidizing agent aqueous solution as in Example 1 and 7 wt % of a fuel solution at 70° C. comprising 79 wt % of light oil, 14 wt % of a PIBSA amine salt emulsifier and 7 wt % of an SMO emulsifier using an emulsifying machine. Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 15 and an acid value of 22.

Test Example 1

The properties and stability of the emulsion compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were measured through typical methods in the art. The results are shown in Tables 1 and 2 below.

TABLE 1
No.	Example 1	Example 2	Example 3	Example 4	Example 5
Oxidizing agent	Ammonium	Ammonium	Ammonium	Ammonium	Ammonium
		nitrate1)	nitrate	nitrate	nitrate	nitrate
						Calcium
						nitrate
PIBSA	Amount (%)2)	2	2	1.5	1.25	0.5
amine salt	Amine value	50	63	50	50	50
emulsifier	Acid value	8	24	8	8	8
SMO	Amount	—	—	—	0.25	—
emulsifier	(wt %)2)
Fuel oil	Kind	Light oil	Light oil	Mineral oil	Mineral oil	Mineral oil
Emulsion long-term	12 weeks or	12 weeks or	12 weeks or	12 weeks or	12 weeks or
storage stability	more	more	more	more	more
Mixing stability	3 weeks or	3 weeks or	3 weeks or	3 weeks or	3 weeks or
		more	more	more	more	more
1)Kind of ammonium nitrate used
1. Granular agricultural ammonium nitrate (UN No. 2067)
A. available from SBU Azot, Russia
B. available from Acron, Russia
2. Granular porous ammonium nitrate for ammonium nitrate fuel oil explosive (UN No. 1942)
A. available from Hubei, China, bulk density of 0.795 g/cc
B. available from Eurochem, Russia, bulk density of 0.709 g/cc
3. Granular high-specific-gravity ammonium nitrate (UN No. 1942)
A. available from Acron, Russia, bulk density of 1.023 g/cc
2)Emulsifier wt % contained in emulsion composition

	TABLE 2
	No.
	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
	Oxidizing agent
			Ammonium nitrate
	Ammonium nitrate1)	Ammonium nitrate	Calcium nitrate	Ammonium nitrate2)
PIBSA amine salt	Amount (wt %)3)	2	1.0	0.5	1.0
emulsifier	Amine value	15	50	15	15
	Acid value	22	8	22	22
SMO Emulsifier	Amount (wt %)3)	—	0.5	—	0.5
Fuel oil	Kind	Light oil	Mineral oil	Mineral oil	Light oil
Emulsion long-term storage stability	Less than 3 weeks	Less than 3 weeks	Less than 3 weeks	12 weeks or more
Mixing stability	Less than 1 week	Less than 1 week	Less than 1 week	3 weeks or more
1)Kind of ammonium nitrate used
1. Granular agricultural ammonium nitrate (UN No. 2067)
A. available from SBU Azot, Russia
B. available from Acron, Russia
2. Granular porous ammonium nitrate for ammonium nitrate fuel oil explosive (UN No. 1942)
A. available from Hubei, China, bulk density of 0.795 g/cc
B. available from Eurochem, Russia, bulk density of 0.709 g/cc
3. Granular high-specific-gravity ammonium nitrate (UN No. 1942)
A. available from Acron, Russia, bulk density of 1.023 g/cc
2)Liquid ammonium nitrate: pure ammonium nitrate synthesized, Hanwha
3)Emulsifier wt % contained in emulsion composition

As is apparent from the results of Tables 1 and 2, the long-term storage stability of the emulsion compositions of Examples 1 to 5 of the present invention was 12 weeks or more, which is evaluated to be very high compared to the emulsion compositions of Comparative Examples 1 to 3 (less than 3 weeks), and the mixing stability with a sensitizer and an ammonium nitrate fuel oil explosive was 3 weeks or more, which is evaluated to be notably different from the emulsion compositions of Comparative Examples 1 to 3 (less than 1 week).

In the emulsion composition of Comparative Example 1, an emulsifying machine was used to realize the desired viscosity of the emulsion, but even when the emulsifying machine was used for a period of time at least 5 times the time of operation of the emulsifying machine in Examples 1 to 5, the viscosity of the emulsion did not reach a desired level, and thus the resulting emulsion was unsuitable for use in bulk emulsion explosives. When the explosive compositions of Comparative Examples 2 and 3 were mixed with a sensitizer and an ammonium nitrate fuel oil explosive, the oxidizing agent in the emulsion was precipitated 2 days after mixing, and thus partial explosion occurred, indicating that the resulting emulsions were unsuitable for use in explosives.

In the emulsion of Comparative Example 4, using the synthesized ammonium nitrate, even when the PIBSA amine salt emulsifier having a low amine value was used and the SMO emulsifier was used in an amount exceeding 20 wt % based on the total weight of the emulsifier, the emulsion composition exhibited long-term storage stability of 12 weeks or more and mixing stability of 3 weeks or more, which is evaluated to be different from the emulsions using other ammonium nitrates.

The bulk density of the emulsion preferably falls in the range of 1.20 to 1.50 g/cc. In the following Examples 6 to 8 and Comparative Examples 4 and 5, the reason why the emulsion having a bulk density of 1.20 to 1.50 g/cc is preferable in the present invention is described in detail.

Example 6

An emulsion was prepared by emulsifying 93 wt % of an oxidizing agent aqueous solution at 80° C. comprising 70 wt % of ammonium nitrate and 30 wt % of water and 7 wt % of a fuel solution at 70° C. comprising 71 wt % of light oil and 29 wt % of a PIBSA amine salt emulsifier using an emulsifying machine. Here, the PIBSA amine salt emulsifier that was used was an emulsifier having an amine value of 50 and an acid value of 8.

Example 7

An emulsion was prepared using the composition including an oxidizing agent aqueous solution at 80° C. comprising 80 wt % of ammonium nitrate and 20 wt % of water, light oil, and a PIBSA amine salt emulsifier in the same wt % as in Example 1. Here, the PIBSA amine salt emulsifier that was used upon emulsion preparation was the same emulsifier as in Example 1.

Example 8

An emulsion was prepared using the composition including an oxidizing agent aqueous solution at 80° C. comprising 46 wt % of ammonium nitrate, 38 wt % of calcium nitrate and 16 wt % of water, light oil, and a PIBSA amine salt emulsifier in the same wt % as in Example 1. Here, the PIBSA amine salt emulsifier that was used upon emulsion preparation was the same emulsifier as in Example 1.

Comparative Example 4

An emulsion was prepared using the composition including an oxidizing agent aqueous solution at 80° C. comprising 60 wt % of ammonium nitrate and 40 wt % of water, light oil, and a PIBSA amine salt emulsifier in the same wt % as in Example 1. Here, the PIBSA amine salt emulsifier that was used upon emulsion preparation was the same emulsifier as in Example 1.

Comparative Example 5

An emulsion was prepared using the composition including an oxidizing agent aqueous solution at 80° C. comprising 20 wt % of ammonium nitrate, 70 wt % of calcium nitrate and 10 wt % of water, light oil, and a PIBSA amine salt emulsifier in the same wt % as in Example 1. Here, the PIBSA amine salt emulsifier that was used upon emulsion preparation was the same emulsifier as in Example 1.

Test Example 2

An emulsion explosive was manufactured by adding the emulsion composition of each of Examples 1 to 5 with 2.0 wt % of hollow glass microspheres (K-15, available from 3M), and the properties and stability thereof were measured through typical methods in the art. The results are shown in Table 3 below.

	TABLE 3
	No.
				Comparative	Comparative
	Example 6	Example 7	Example 8	Example 4	Example 5
	Oxidizing agent
					Ammonium
	Ammonium	Ammonium	Ammonium	Ammonium	nitrate1)
	nitrate1)	nitrate1)	nitrate1)	nitrate1)	Calcium nitrate
Water (wt %)2)	30	20	16	40	10
Emulsion bulk density (g/cc)	1.20	1.35	1.50	1.10	1.60
Emulsion long-term storage	12 weeks or	12 weeks or	12 weeks or	12 weeks or	Less than 5
stability	more	more	more	more	weeks
Speed of explosion of emulsion	2500	3500	3500	Partial	4000
explosive3) (m/sec)				explosion
Explosion heat (kcal/	1683	2327	2487	1039	1609
1)Kind of ammonium nitrate used
1. Granular agricultural ammonium nitrate (UN No. 2067)
A. available from SBU Azot, Russia
B. available from Acron, Russia
2. Granular porous ammonium nitrate for ammonium nitrate fuel oil explosive (UN No. 1942)
A. available from Hubei, China, bulk density of 0.795 g/cc
B. available from Eurochem, Russia, bulk density of 0.709 g/cc
3. Granular high-specific-gravity ammonium nitrate (UN No. 1942)
A. available from Acron, Russia, bulk density of 1.023 g/cc
2)Water wt % contained in oxidizing agent aqueous solution
3)Speed of explosion of explosive, resulting from testing in the state of sealed in a carbon steel pipe having a diameter of 50 mm and a length of 350 mm.

As is apparent from the results of Table 3, the long-term storage stability of the emulsion compositions of Examples 6 to 8 of the present invention was 12 weeks or more, which is evaluated to be notably different from the emulsion composition of Comparative Example 5 (less than 5 weeks).

In the emulsion composition of Comparative Example 4, when the emulsion explosive was manufactured and subjected to an explosion speed test, partial explosion occurred, and the calculated explosion heat energy was very low, and thus the resulting emulsion was unsuitable for use in explosives.

Based on the test results, in order to prepare an emulsion having a bulk density of less than 1.2 g/cc, when water, having relatively low specific gravity, was used in an increased amount, the resulting emulsion only partially exploded when used as an emulsion explosive. On the other hand, in order to prepare an emulsion having a bulk density exceeding 1.5 g/cc, when ammonium nitrate or calcium nitrate was used in an increased amount as the oxidizing agent, there was a significant difference in stability. Hence, the bulk density of the emulsion for an emulsion explosive according to the present invention is preferably limited to the range of 1.2 to 1.5 g/cc.

According to the present invention, an emulsion composition for an emulsion explosive can be manufactured at low cost and can exhibit superior stability compared to conventional emulsions for emulsion explosives.

In particular, the emulsion composition for an emulsion explosive according to the present invention is capable of exhibiting superior long-term storage stability and mixing stability and also of reducing material costs by about 12% by virtue of the use of ammonium nitrate including a solidification inhibitor and other organic or inorganic materials, such as agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive or high-specific-gravity ammonium nitrate, which is granular ammonium nitrate having a price, on average, of about 80% compared to conventional liquid ammonium nitrate.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments and that various changes and modifications may be made therein without departing from the spirit of the present invention, and are thus incorporated in the present invention.

Claims

1. An emulsion composition for an explosive, comprising an oxidizing agent aqueous solution including, as granular ammonium nitrate added with an organic or inorganic material including a phase-transition inhibitor, a solidification inhibitor or a coating agent, at least one of agricultural ammonium nitrate, porous ammonium nitrate for an ammonium nitrate fuel oil explosive and high-specific-gravity ammonium nitrate, and a fuel solution including an emulsifier and an oil,

wherein the emulsifier includes a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65.

2. The emulsion composition of claim 1, comprising 85 to 95 wt % of the oxidizing agent aqueous solution, 0.3 to 5 wt % of the emulsifier, and 3 to 10 wt % of the oil, based on a total weight of an emulsion.

3. The emulsion composition of claim 1, wherein the oxidizing agent aqueous solution further includes at least one of potassium nitrate and sodium nitrate.

4. The emulsion composition of claim 1, wherein the emulsifier further includes 20 wt % or less of SMO (sorbitan monooleate) based on a total weight of the emulsifier.

5. The emulsion composition of claim 1, wherein the oil is at least one selected from the group consisting of mineral oil and light oil.

6. The emulsion composition of claim 1, wherein an emulsion has a bulk density of 1.20 to 1.50 g/cc.

7. The emulsion composition of claim 1, wherein the PIBSA amine salt is contained in an amount of 100 wt % or less but exceeding 80 wt % based on a total weight of the emulsifier.

8. The emulsion composition of claim 1, wherein the organic or inorganic material including the phase-transition inhibitor, the solidification inhibitor or the coating agent includes at least one selected from among magnesium nitrate, silicate, clay, aluminum sulfate, diatomaceous earth, talc, and an amine salt.

9. A method of preparing an emulsion composition for an explosive, the method comprising:

preparing an oxidizing agent aqueous solution including ammonium nitrate added with an organic or inorganic material including a phase-transition inhibitor, a solidification inhibitor or a coating agent at 50° C. to 95° C.; and

preparing an emulsion by emulsifying the oxidizing agent aqueous solution at 50° C. to 95° C. using a fuel solution including an emulsifier and a fuel oil, without an additional filtration or purification process,

wherein the emulsifier includes a PIBSA (polyisobutylene succinic anhydride) amine salt having an acid value of 30 or less and an amine value of 45 to 65.

10. The method of claim 9, wherein the emulsion composition has a bulk density of 1.20 to 1.50 g/cc.

11. The method of claim 9, wherein the emulsion composition comprises 85 to 95 wt % of the oxidizing agent aqueous solution, 0.3 to 5 wt % of the emulsifier, and 3 to 10 wt % of the oil, based on a total weight of the emulsion.

12. The method of claim 9, wherein the PIBSA amine salt is contained in an amount of 100 wt % or less but exceeding 80 wt % based on a total weight of the emulsifier.

13. The method of claim 9, wherein the organic or inorganic material including the phase-transition inhibitor, the solidification inhibitor or the coating agent includes at least one selected from among magnesium nitrate, silicate, clay, aluminum sulfate, diatomaceous earth, talc, and an amine salt.