KR100824932B1 - Explosive - Google Patents

Abstract

The present invention relates to a water-in-oil emulsion explosive comprising an ethylene vinyl acetate copolymer. This explosive has long term stability. The explosives of the present invention did not degrade the explosive performance even after being stored for about one year under load, and were slightly agglomerated to cause a slightly entangled partial solidification that could be easily disassembled. Even after long-term storage, the explosives could be easily loaded with a charger. Since explosives are excellent in water resistance, they are also suitable for blasting water holes.

Description

Explosives             

The present invention relates to explosives. More specifically, the present invention relates to water-in-oil emulsion explosives used in industrial blasting operations such as tunnel drilling, quarrying and mining.

As industrial explosives used in blasting operations, dynamite, hydrous explosives, ammonium nitrate explosives and ammonium nitrate-emulsion explosives (hereinafter referred to as ANFO explosives) are well known in the art. Of these explosives, water-containing explosives that do not contain gunpowder components are considered safer than conventional dynamite, and are widely used as industrial explosives. These water-containing explosives are classified into two types of explosives such as slurry explosives and emulsion explosives, and the emulsion type has characteristics that are excellent in moldability and weather resistance. This emulsion explosive has been variously modified since its publication in US Pat. No. 3,161,551 as a water-in-oil emulsion explosive. Nowadays, it is possible to obtain an excellent explosive having a performance which the explosive does not have in terms of water resistance and safety.

On the other hand, at the blasting site, the mechanization of the explosives loading is desired in view of simplifying the operation of loading the explosives and securing the safety during handling. Since it is necessary to make the explosives safer during the mechanized loading operation, a method of loading ANFO explosives with mechanized loading equipment such as a loader has been put to practical use in mines and quarries. However, compared with emulsion explosives, since ANFO explosives have a bad residual gas composition after blasting, it is required to provide a sufficient exhaust device. When used under conditions where water is present in the blast holes, the ANFO explosives are soluble in water and therefore cannot achieve their intended explosive performance and, as a result, are difficult to use. To insert ANFO explosives into blast holes or spring holes where water is present, first drain the blast holes before mounting the poly-tubes, and then place the poly-tubes in the blast holes. Afterwards, a cumbersome step may finally be required to insert ANFO explosives into the poly-tube. For example, a water-in-oil emulsion explosive, called a bulk emulsion explosive, is directly blown out using an air-driven mono-pump by a method according to the Review Report on Effective Tunneling Technology published by the Japan Tunnel Technology Association (JTA). Bulk emulsion blasting systems that autoload in air have already been put to practical use. However, in the bulk emulsion blasting system, since high viscosity water-in-oil emulsion explosives are used, there is a concern that high cost may be caused due to the trouble of clean operation or management of residual explosives after the loading operation. In addition, in order to secure the bulk emulsion explosives, expensive mechanized loading equipment is required in terms of securing stability.

Therefore, it is possible to load with a relatively simple mechanical equipment such as an air loader, and a high-explosive explosive that can be used even in a blasting hole having a relatively large amount of water is desired. In order to solve these problems, development of water-in-oil emulsion explosives in the form of granules or granules disclosed in Japanese Patent Laid-Open Nos. 223888/1995 and 278975/1999 is underway.

By the way, the granulation and granulation methods disclosed in the above publication first crystallize the aqueous inorganic oxidizing agent solution in the emulsion to crush the emulsion structure to granulate.

In general, it is known that crystallization of an aqueous oxidant solution of a water-in-oil type emulsion explosive causes the emulsion to collapse from the crystallization portion, resulting in loss of sensitivity and performance as explosive. Even the explosives used in this way, if so-called "local mixing methods" or similar methods are applied, it is not a problem if the explosives are stored for a short time such as several hours or several days before they are used from the manufacture of the explosives. However, the period from the manufacture of explosives to use generally ranges from several months or longer to about six months to about one year. Therefore, even granules or granular water-in-oil emulsion explosives require excellent stability over several months without crystallizing the oxidizing agent aqueous solution. In particular, it is desirable to keep the water-in-oil emulsion explosives stable so that their properties remain unchanged in order to counter the mechanical loading.

When explosives molded into granules are loaded with prolonged storage, mechanical loading, or the like, the drug is agglomerated and the coagulation is not broken at the time of use. Therefore, a granular water-in-oil emulsion explosive that is not aggregated even under a load such as long-term storage or loading by a machine or is easily disassembled even when aggregated is desired.

The present inventors have intensively studied to solve the above problems, and as a result, replace all or a part of the continuous phase components of the water-in-oil emulsion with ethylene vinyl acetate acetate copolymer; Or the inclusion of ethylene vinyl acetate copolymer has resulted in the completion of the present invention by the discovery that a solid and explosive solid explosive, ie a water-in-oil emulsion explosive, can be obtained for several months.

That is, the present invention relates to the following (1) to (9):

(1) a water-in-oil emulsion explosive characterized by containing an ethylene vinyl acetate copolymer in a continuous phase,

(2) the water-in-oil emulsion explosive of (1), which contains 0.2 to 8% by mass of ethylene vinyl acetate copolymer with respect to the total amount of explosive,

(3) an oil-in-water emulsion explosive, characterized in that it contains an oxidizing agent, an oil substance, an ethylene vinyl acetate copolymer, an emulsifier and a micro hollow sphere;

(4) The emulsion explosive of (3), wherein the microspheres are glass microbaloons or resin microbaluns.

(5) the water-in-oil emulsion explosive of (3), characterized in that it contains ethylene vinyl acetate copolymer in an amount of 30% by mass or more based on the total mass of the oil material and the ethylene vinyl acetate copolymer,

(6) the emulsion explosive of (3), wherein the melt flow rate of the ethylene vinyl acetate copolymer is 10 g / 10 minutes or more;

(7) the emulsion explosive of (3), wherein the number average molecular weight of the ethylene vinyl acetate copolymer is 100 to 50,000 Mn,

(8) the emulsion explosive of any of the above (1) to (7), characterized in that it is a solid,

(9) The emulsion explosive charge of (8), which is formed into a columnar shape having a diameter of 3 to 20 mm and a length of 1 to 30 mm.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in detail. In the following description, "parts" and "%" are based on mass unless otherwise indicated.

The continuous phase of the water-in-oil emulsion explosive according to the invention is preferably an oil phase (fuel phase) and is usually a mixture containing both an oil substance and an ethylene vinyl acetate copolymer (hereinafter may be referred to as EVA resin). The oil phase present in the continuous phase in the present invention does not necessarily contain an oil substance and may be formed by an EVA resin or a resin mixture of EVA resin and another resin.

Since the EVA resin has a property of curing or weakening its viscosity by heating, injection molding is preferable when it is made of a mixture of an oxidizing agent, water, an emulsifier and a micro hollow sphere, as well as an oil material if necessary. More specifically, EVA resins which are usually used have a number average molecular weight of 100 to 60,000 Mn, preferably 100 to 50,000 Mn. It is more preferable that number average molecular weight is 2,000 Mn or more, and it is still more preferable that it is 10,000-40,000 Mn.                 

The EVA resin used in the present invention may be a copolymer including other copolymer components if the ethylene vinyl acetate copolymer is included as a main component. When the EVA resin is a copolymer including other copolymers, it is preferable to contain 30 to 100% of the ethylene vinyl acetate copolymer with respect to the total EVA resin, more preferably 50 to 100%, more preferably 70 to 100% Even more preferable. Most preferred are ethylene vinyl acetate copolymers that are substantially free of other copolymer components. As long as it is an ethylene vinyl acetate copolymer, the ratio of ethylene to vinyl acetate is not particularly limited, but in general, a vinyl acetate: ethylene molar ratio of 1: 9 to 1:15 is preferred.

Ethylene vinyl acetate copolymer may be included in an amount sufficient to effectively carry out the present invention, preferably at least 0.2%, more preferably at least 0.4%, even more preferably at least 0.6% relative to the total explosive amount of the present invention. And 8% or less, more preferably 6% or less, even more preferably 4% or less. Although depending on the type of ethylene vinyl acetate, the most preferred range is usually about 0.6 to 3%.

The continuous phase in the present invention is preferably a mixture comprising the oily material described below and an ethylene vinyl acetate copolymer. The resin contained in the continuous phase may be EVA resin alone, but resins other than ethylene vinyl acetate copolymer may also be contained as long as the present invention can be practiced effectively. Other resins may preferably exhibit oil solubility or compatibility with oil materials.                 

The other resins include thermosetting resins, thermoplastic resins, synthetic rubbers, and the like. More specifically, vulcanized rubber, petroleum resin, phenol resin, AAS resin, ABS resin, PET resin, urea resin, melamine resin, epoxy resin, unsaturated polyester resin, polyurethane resin, polyvinyl chloride, polyvinyl acetate, polyamide Resins, polyimide resins and polyethylene resins are included, but in order to maintain the stability of the water-in-oil emulsion explosives, resins which do not exhibit reactivity with other components are preferred. Also preferred are thermosetting resins that are liquid at room temperature or have a low melting point and thermoplastic resins that are solid at room temperature but exhibit fluidity upon heating. Examples include phenolic resins, petroleum resins, polyethylene, polypropylene, polybutene, polyisobutylene, ethylene vinyl acetate copolymer resins, polybutadiene and styrene-butadiene rubbers, including petroleum resins and ethylene vinyl acetate copolymer resins. desirable. Among them, optionally hydrogenated petroleum resins, for example aliphatic or C ₅ -petroleum resins obtained from C ₅ -oils of cracked oils, aromatic or C ₉ -petroleum resins obtained from C ₉ -oils, or two oils C ₅ C ₉ copolymerized petroleum resin can be used. Examples of the resin obtained from the C ₅ -oil include copolymers such as isoprene, pipeylene, 2-methylbutene-1 and 2; Conjugated diolefins usually have a ring structure and a representative structure is represented by the following formula:

Where

m and n represent the number of repeat units.

The resin obtained from the C ₉ -oil is a copolymer containing styrene, vinyl toluene, α-methylstyrene, indene and the like as main components and is generally represented by the following formula:

Where

n represents the number of repeat units.

As used herein, the term "oil mixture" refers to a mixture of EVA resins and oil materials and / or EVA resins unless otherwise noted.                 

In the present invention, the continuous phase is in the form of an oil mixture. The EVA resin ratio to the total amount of oil material and EVA resin is not particularly limited as long as the present invention can be effectively implemented, but is usually 10% or more, preferably 20% or more; In some cases, the entire oil mixture may be an EVA resin. More preferably, however, the EVA resin is comprised between 30 and 80% relative to the total content of the oil mixture. When used together with other resins, it is preferable to include EVA resin in an amount equal to or greater than the lower limit so that the total amount of EVA resin and other resins is equal to or less than the upper limit. The preferred content of EVA resin varies somewhat depending on its molecular weight, while high molecular weight EVA resins are included in relatively small amounts, while low molecular weight EVA resins tend to be included in relatively large amounts. For example, when the number average molecular weight is at least 10,000, preferably at least 12,000, more preferably at least 20,000, the content thereof may be 60% or less, preferably 25 to 50% relative to the total content. In the case of a low molecular weight EVA resin having a number average molecular weight of about 2,000 to 3,000, the content thereof may be 50% or more, more preferably about 60 to 80%.

In the method for producing a water-in-oil emulsion explosive of the present invention, it is preferable that the EVA resin usually used in a molten state is melted at a production temperature. For example, it is preferable to use an EVA resin having a melt-flow rate of 10 g / 10 minutes or more, preferably 15 g / 10 minutes or more, according to the "flow test method of thermoplastic resin" (JIS K7210). .

When other resins are used together with the EVA resin, the same conditions as above can be applied.

The number average molecular weight of the resin can be measured by gel permeation chromatography or the like.

Explosives of the invention generally comprise an oily substance. Oil materials typically used in water-in-oil emulsion explosives can be used. The oily substance improves the emulsification of the emulsion to form a continuous phase with the EVA resin. Examples of oil substances include petroleum oils such as light oil, coal oil, mineral oil, lubricating oil and heavy oil; Petroleum waxes such as paraffin wax and microcrystalline wax; And other oil substances such as hydrophobic vegetable oils, vegetable waxes, animal oils and animal waxes, which may be used alone or in combination of two or more thereof.

The oil mixture of the present invention comprising an oily substance is usually contained in the explosive in the range of 0.1 to 20%, preferably 1 to 10%. In a preferred embodiment of the present invention, when a resin having a number average molecular weight of 100 to 50,000 is used, the amount of the oil mixture used in the explosive is usually 0.1% or more, preferably 0.5% or more, more preferably, based on the total content 1% or more, even more preferably 1.5% or more. Its upper limit is generally about 10%, preferably 7% or less. The most preferred range is about 2 to about 5%.

Emulsifiers used in the explosives of the present invention include emulsifiers commonly used in water-in-oil emulsion explosives, examples of which include fatty acid salts having from about 15 to about 30 carbon atoms such as alkali metal stearate, ammonium stearate and calcium stearate ( Alkali metals, alkaline earth metals and ammonium salts, etc.); Polyoxyethylene ethers; Fatty acid esters, preferably fatty acid esters having 15 to 30 carbon atoms, such as sorbitan fatty acid esters and sorbitol fatty acid esters. One kind or a mixture of two or more kinds are used. The amount of emulsifier used in the explosive is 0.1% or more, preferably 0.5% or more, more preferably 1% or more, based on the total content, the upper limit is usually about 10%, preferably 7% or less, more preferably 5 % Or less

The oxidant used in the explosive of the present invention is preferably in the form of an aqueous solution thereof. The oxidizing agent includes nitrate or perchlorate, and specific examples thereof include alkali metal nitrates such as sodium nitrate; Alkaline earth metal nitrates such as calcium nitrate; Alkali metal chlorates such as ammonium nitrate or sodium chlorate; Alkaline earth metal chlorates such as calcium chlorate; Alkali metal perchlorates such as potassium perchlorate; Alkaline earth metal perchlorates such as calcium perchlorate; And ammonium perchlorate. These can be used individually or in mixture of 2 or more types. Among these, the most preferred oxidizing agents are ammonium nitrate and sodium nitrate. As described later, it is preferable to appropriately adjust the content of the oxidizing agent in the aqueous oxidizing agent so that the crystallization temperature of the aqueous solution becomes 30 to 90 ° C according to the purpose of use. Thus, depending on the type of oxidant, its content is usually 60 to 95%, preferably 70 to 93%, more preferably 85 to 92%.

In the oxidizing agent aqueous solution of this invention, water-soluble amine nitrates, such as a monomethylamine nitrate, a monoethylamine nitrate, a hydrazine nitrate, and a dimethylamine dinitrate; Water-soluble alkanolamine nitrates such as methanolamine nitrate and ethanolamine nitrate; And auxiliary sensitizers such as water soluble ethylene glycol mononitrate may be added.

The aqueous solution of oxidant used in the present invention is preferably appropriately adjusted so that the crystallization temperature of these aqueous solutions is 30 to 90 ° C. The content of water in the oxidant aqueous solution relative to the total solution is usually 5 to 40%, preferably 7 to 30%, with 8 to 15% being particularly preferred. In order to lower the crystallization temperature of the oxidizing agent aqueous solution, a water-soluble organic solvent such as methanol, ethanol, formamide, ethylene glycol, glycerol may be used as an auxiliary solvent. In the explosives of the present invention, the aqueous solution of oxidant (in some cases, an auxiliary solvent may also be included) is other than other components, and preferably 60 to 97%, more preferably 80 to 95% of the total content of the explosive. It may be contained in the range.

An appropriate amount of a density reducing agent, preferably a micro hollow sphere, can be added to the composition of the water-in-oil emulsion explosive of the present invention, and the sensitivity performance of the explosive can be extensively adjusted from electroencephalogram to booster detonation. Commonly used density reducing agents have a density of 0.8 g / cc or less, preferably 0.5 g / cc or less, more preferably 0.3 g / cc or less. In the case of organic reagents, a density of 0.1 g / cc or less, or a reagent of density of 0.05 g / cc or less may also be used if desired. Density reducing agents may include any material as long as they are inert and of low density, but micro hollow spheres are preferred to achieve stable explosive performance. As micro hollow spheres, For example, organic micro hollow spheres, such as glass micro balun and a siltic micro balun; And organic microspheres such as styrofoam and resin microballoons are used in one kind or in a mixture of two or more kinds; Glass microballoons or resin microballoons are preferred, and glass microballoons are most preferred. The use of the density reducing agent may vary widely depending on the explosive use and the relative density of the microspheres, but they usually have a density of at least 0.8 g / cc, preferably at least 0.9 g / cc, more preferably 1 g. / cc or higher; It is used in an amount providing up to 1.4 g / cc, preferably up to 1.3 g / cc. The preferred blending ratio range of the density reducing agent is about 0.1 to about 10%, more preferably 1 to 8%, even more preferably 1 to 6%, based on the total explosive amount; In some cases, the most suitable range is 2 to 5%. In the case of the glass microballoon which is a preferred embodiment of the present invention, the preferred blending ratio is 1% or more, in some cases 2% or more, 8% or less, more preferably 5% or less.

Metal powders such as aluminum powder and magnesium powder in the explosives of the present invention; And organic powders such as wood flour and starch may also be added. Depending on the type of medicament and its intended use, it may be added to the explosive in an amount ranging from 0 to 10%.

The explosives of the present invention are produced, for example, according to the following method.

That is, the above-described oxidant and, if necessary, the above-mentioned auxiliary sensitizer are dissolved in water at about 85 to 95 ° C. to obtain an oxidizing agent aqueous solution. In addition, oil mixture components (such as EVA resins and oil materials, and other resins other than EVA resins as necessary) and emulsifiers are sufficiently mixed under heat melting conditions to obtain an oil mixture containing an emulsifier. Subsequently, the aqueous oxidant solution is slowly added to the oil mixture heated to about 85 to 95 ° C. with sufficient stirring to obtain a base water-in-oil emulsion explosive base material. The water-in-oil emulsion explosive of the present invention is then added to a water-in-oil emulsion while maintaining the above temperature by adding a density reducing agent, for example, a tool in a micro and other additives as necessary, and then mixing with a kneader. . The explosives obtained are cooled to room temperature or cooled to room temperature and then transferred to a molding machine and molded to obtain the molding explosives of the present invention. When a water-in-oil emulsion is obtained, part of the oil mixture component can be added simultaneously with the addition of the microspheres. For example, the oil substance and the emulsifier may be first mixed to obtain a water-in-oil emulsion, and then mixed with addition of a micro hollow sphere and an EVA resin at the same time; The EVA resin and the emulsifier are first mixed to obtain a water-in-oil emulsion, and then mixed with addition of a micro hollow sphere and an oil substance at the same time; Usually, it is preferable to mix the oil mixture component and the emulsifier first to obtain a water-in-oil emulsion with an oil mixture containing an emulsifier, and then to add microspheres.

The water-in-oil emulsion explosive of the present invention thus obtained is preferably molded into a suitable form by a conventional method. There is no particular limitation on the shape of the explosives of the present invention, and they may be formed into any shape such as spherical, cylindrical, disc or oblong according to the molding machine used. The explosive may be shaped into any shape, but its dimensions preferably have a maximum length (length of the longest face or maximum diameter in its shape) of 30 mm or less, more preferably 20 mm or less; It is preferable that the minimum length (length or minimum diameter of the shortest side in its shape) is 1 mm or more, more preferably 3 mm or more.

The method for producing explosives of the present invention includes a conventional method using an extruder or a method of granulating a water-in-water emulsion explosive in a pulverizer or the like and then granulating it with a granulator. However, the extrusion method is preferred because the latter method involves complicated steps. More specifically, water-in-oil emulsion explosives are extruded through hole-plates or screens to obtain rod-shaped explosives, which are then cut to a suitable length with a knife or wire to obtain columnar explosives. In the molding explosive of the present invention, if its size is too large, the porosity increases when loaded in the blasting hole, thereby reducing the width, so that the diameter size is 3-20 mm and the length is 1-30 mm, preferably the diameter size is It is 5-10 mm and the length is about 3-20 mm.

The explosives of the present invention molded into a cylindrical shape can be prepared by a simple method such as a conventional method of preparing a water-in-oil emulsion explosive.

Example

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1

An aqueous solution of oxidizer at 90 ° C. containing 75.0 parts of ammonium nitrate, 4.8 parts of sodium nitrate, and 10.6 parts of water, was added 1.5 parts of microcrystalline wax, ethylene-vinyl acetate copolymer (EVAFLEX P-2807; number average molecular weight 20,000-30,000 Mn; melt-flow Rate: 15 g / 10 min; from Du pont-Mitsui Polychemicals Co., Ltd.) 1.4 parts and 2.9 parts of sorbitan monooleate and added with sufficient stirring to give a water-in-oil emulsion. 3.8 parts (density: 0.25 g / cc) of glass microballoons were added here as a micro hollow sphere, and it stirred and mixed, and obtained the water-in-oil emulsion explosive of this invention. The water-in-oil emulsion explosives were molded with an extruder having a diameter of 8 mm, and cut to a length of 10 mm with a knife to obtain an explosive of the present invention. The density of the explosive obtained was 1.17.

Example 2

An aqueous solution of oxidant at 90 ° C. containing 75.0 parts of ammonium nitrate, 4.8 parts of sodium nitrate, and 10.6 parts of water, was added 1.5 parts of microcrystalline wax, ethylene-vinyl acetate copolymer (Ultracen 720; number average molecular weight about 37,000 Mn; melt-flow rate: 150 g / 10 min; product from Tosoh Corporation) 1.4 parts and 2.9 parts of sorbitan monooleate and stirred thoroughly to give a water-in-oil emulsion. 3.8 parts (density: 0.25 g / cc) of glass microballoons were added here as a micro hollow sphere, and it stirred and mixed, and obtained the water-in-oil emulsion explosive of this invention. The water-in-oil emulsion explosives were molded with an extruder having a diameter of 8 mm, and cut to a length of 10 mm with a knife to obtain an explosive of the present invention. The density of the explosive obtained was 1.17.

Comparative Example 1

An aqueous oxidizing agent at 90 ° C. containing 75.0 parts of ammonium nitrate, 4.8 parts of sodium nitrate, and 10.6 parts of water was added to a mixture of 3.8 parts of microcrystalline wax and 2.0 parts of sorbitan monooleate, followed by sufficiently stirring and mixing to obtain a water-in-oil emulsion. 3.8 parts (density: 0.25 g / cc) of the same glass microballoon as in Example were added as a micro hollow sphere and stirred and mixed to obtain a water-in-oil emulsion explosive of the present invention. The water-in-oil emulsion explosives were molded with an extruder having a diameter of 8 mm, and cut to a length of 10 mm with a knife to obtain an explosive of the present invention. The density of the explosive obtained was 1.17.

The composition ratio of each water-in-oil emulsion explosive obtained in Examples 1 to 2 and Comparative Example 1 is shown in Table 1 below.

Creation costs Example 1 Example 2 Comparative Example 1  Ammonium Nitrate 75.0 75.0 75.0  Sodium nitrate 4.8 4.8 4.8  water 10.6 10.6 10.6  Microcrystalline Wax 1.5 1.5 3.8  Sorbitan monooleate 2.9 2.9 2.0  EVAFLEX P-2807 1.4 - -  Ultracen 720 - 1.4 -  Glass Microballoons 3.8 3.8 3.8

Test Example

The explosives obtained in Examples 1 to 2 and Comparative Example 1 were loaded using an air loader in steel pipes having an inner diameter of 48 mm, a length of 1 mm, and a wall thickness of 5 mm, and a water-containing explosive manufactured by Nippon Kayaku Co., Ltd. as a booster ( After agitation using 50 g of a trade name: Altex, the explosion rate was measured by the d'Autriche method.

After filling the same steel pipe with water in advance, each explosive was loaded using an air loader as described above, and the explosion speed was also measured.                 

 In addition, for the storage test, the obtained explosives were charged into a plastic bag of 15 to 20 cm thick and stored at room temperature for 6 months / 1 year, respectively. Explosion rates were measured in dry and wet tubes, respectively, in the same manner as above. The results are shown in Table 2 below.

In order to test the cohesiveness and ease of disintegration of explosives under load, 20 kg each of the explosives obtained in Examples 1 and 2 and Comparative Example 1 was actually packaged (put in a bag and packed in a cardboard box), and then at room temperature for 6 Stored months / year. The explosive condition was evaluated after 6 months / 1 year of storage. The test results are shown in Table 2 below.

Performance test results Explosion Speed (m / s) Example 1 Example 2 Comparative Example 1 Elapsed time Right after manufacturing Drying Hall 2824 2970 3120 Wet Hole 3110 3210 3430 6 months later Drying Hall 2970 2890 Inmeasurement Wet Hole 3280 3190 Inmeasurement 1 year later Drying Hall 2930 3030 Inmeasurement Wet Hole 3220 3300 Inmeasurement High Mars Elapsed time 6 months later Slight partial cohesion Slight partial cohesion Cohesion 1 year later Slight partial cohesion Slight partial cohesion Cohesion Cohesive disassembly ease Elapsed time 6 months later Dragon Dragon Difficulty 1 year later Dragon Dragon Difficulty

Comments on performance test results:

As shown in Table 2 above, the explosives of the present invention retained their initial properties and performance without aggregation after storage for 1 year under unloaded conditions at room temperature. In contrast, the explosives of the comparative example could measure the explosion rate immediately after manufacture, but aggregated after 6 months of storage even under unloaded conditions. Thus, it was not possible to measure the explosion rate as given in Table 2.

Furthermore, with regard to cohesion under load, the explosives of the present invention showed partial and slight cohesion 6 months and 1 year after storage. However, his agglomeration was easily separated even with a slight impact, and there was no problem during loading with the loader. However, the explosives of the comparative example agglomerated to the extent that coagulation could hardly be disassembled after 6 months / 1 year of storage, and therefore it was difficult to load with a loader.

Example 3

An aqueous solution of oxidant at 90 ° C. containing 75.0 parts of ammonium nitrate, 4.8 parts of sodium nitrate and 10.6 parts of water was added to 2.0 parts of microcrystalline wax, ethylene-vinyl acetate copolymer ((Ultracen 722; melt-flow rate: 400 g / 10 min; Tosoh). Corporation) and 0.9 parts of sorbitan monooleate and 2.9 parts of sorbitan and stirred thoroughly to obtain a water-in-oil emulsion, to which 3.8 parts of glass microballoons (density: 0.25 g / cc) are added as micro hollow spheres. The water-in-oil emulsion explosives of the present invention were obtained by molding the water-in-oil emulsion explosives with an extruder having a diameter of 8 mm, and cut to a length of 10 mm with a knife to obtain the explosives of the present invention. The density of the explosive was 1.17.                 

The explosive rate obtained, the cohesiveness and the ease of flocculation were tested for the explosive obtained in the same manner as in Test Example. The results are shown in Table 3 below.

The water-in-oil emulsion explosives of the present invention showed little deformation or aggregation after long-term storage such as 6 months or 1 year under load, and only slight partial coagulation occurred; Agglomeration could easily be separated and showed excellent long term stability and excellent water resistance. Therefore, when the explosive of the present invention is appropriately molded, it can be easily loaded in the blasting hole using an air loader or the like, and can also be used in the water hole without loss of its explosive performance.

The residual gas composition after blasting was also good compared to ANFO explosives.

Claims (9)

In a continuous phase, the oil material and the ethylene vinyl acetate copolymer containing 30 to 80% by mass of the ethylene vinyl acetate copolymer, characterized in that molded in a shape having a maximum length of 30 mm or less and a minimum length of 1 mm or more. Water-in-oil emulsion explosives. The water-in-oil emulsion explosive according to claim 1, which contains 0.2 to 8 mass% of ethylene vinyl acetate copolymer based on the total amount of explosive. The water-in-oil emulsion explosive according to claim 1, which contains an oxidizing agent, an oil substance, an ethylene vinyl acetate copolymer, an emulsifier and a micro hollow sphere. The emulsion explosive of claim 3, wherein the microspheres are glass microbaloons or resin microballoons. delete The emulsion explosive of claim 3, wherein the melt flow rate of the ethylene vinyl acetate copolymer is at least 10 g / 10 minutes. The emulsion explosive of claim 3, wherein the number average molecular weight of the ethylene vinyl acetate copolymer is from 100 to 50,000 Mn. delete 2. The emulsion explosive of claim 1, wherein the emulsion is formed into a columnar shape having a diameter of 3 to 20 mm and a length of 1 to 30 mm.