JP2004238235A - Bursting charge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a shaped bursting charge from a water-in-oil emulsion explosive capable of being easily charged by means of a charger, excellent in long-term stability, and resistant to caking under a load or the like. <P>SOLUTION: The bursting charge is prepared by adhering a powder having a mean particle size of at most 500 μm to the surface of a water-in-oil emulsion explosive. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００３５】
【表２】

【００３６】
なお、表２の「解れ易さ」は、容易は袋を軽くゆする程度の振動で解れる程度を、比較的容易は手で軽く力を加えると簡単に解れる程度をそれぞれ示す。
【００３７】
【表３】

【００３８】
表２及び表３の結果から明白なように、本発明の爆薬は荷重により塊化し難く、かつ装填機で装填が可能で、１年程度貯蔵したものでも、爆薬としての性能を十分維持していることが明白である。
【００３９】
【発明の効果】
本発明の爆薬は、油中水滴型エマルション爆薬の爆薬性能を低下させることなく、容易に機械装填できる粒状の爆薬であり、更には荷重により塊化し難く、塊化しても容易に解す事ができ、長期経時安定性があり、水孔でも使用可能であるため極めて有用である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to explosives. More particularly, the present invention relates to a water-in-oil emulsion explosive used for industrial blasting operations such as tunnel excavation, quarrying, and mining.
[0002]
[Prior art]
As industrial explosives used for blasting operations and the like, dynamite, hydrous explosives, nitrite explosives, and nitrate oil explosives (hereinafter referred to as ANFO explosives) are well known. Among these explosives, hydrous explosives are relatively safer than conventional dynamite because they do not contain a high-risk explosive component in the composition, and have been widely used as industrial explosives. These water explosives are broadly classified into two types, slurry explosives and emulsion explosives. Emulsion explosives are characterized by being more excellent in moldability and weatherability. Since this emulsion explosive was published as Patent Document 1 as a water-in-oil type emulsion explosive, various improvements have been made. At present, it has better performance than conventional explosives in terms of water resistance and safety. What you have is obtained.
[0003]
On the other hand, at the blasting site, there is an increasing demand for mechanized explosive charging work from the viewpoints of simplifying explosive charging work and ensuring safety when handling explosives. In order to carry out the mechanical loading operation of explosives, it is necessary that the explosives used are safer, and a method of mechanically loading the ANFO explosives with a loader or the like has been put to practical use in mines and quarries.
[0004]
However, since the ANFO explosive has a poor residual gas composition after blasting as compared with a water-in-oil emulsion explosive, it is necessary to provide a sufficient exhaust device. Further, when water is present in the blast hole, the ANFO explosive dissolves in water and a predetermined explosive performance cannot be obtained, so that it becomes difficult to use the explosive. For this reason, in a blast hole or a spring hole where water exists, a complicated method such as discharging the water in the blast hole in advance, inserting a polytube or the like, and then loading an ANFO explosive into the polytube. May be performed. As for the water-in-oil emulsion explosive, for example, in various countries, as described in Non-Patent Document 1, a water-in-oil emulsion explosive called a bulk emulsion explosive is directly blasted using an air-driven monopump or the like. A method referred to as a bulk emulsion explosive system for automatic loading into a container has already been put to practical use. However, with respect to the bulk emulsion explosive system, a high-viscosity water-in-oil emulsion explosive is used, so that cleaning work after charging and management of residual explosives become complicated, which may lead to an increase in cost. In addition, in order to load a bulk emulsion explosive, an expensive loading machine is required to ensure safety.
[0005]
For this reason, there is a demand for a highly safe explosive that can be loaded by a relatively simple machine such as an air loading machine and can be used even in a blast hole where a relatively large amount of water exists. As explosives for solving these problems, for example, granular or granular water-in-oil emulsion explosives described in Patent Literature 2, Patent Literature 3, Patent Literature 4, Patent Literature 5, and the like have been developed.
[0006]
However, the method of granulating or granulating a water-in-oil emulsion explosive described in Patent Documents 2 and 3 described above involves crystallizing an aqueous solution of an inorganic oxidizing agent in the emulsion, breaking the emulsion structure, and then forming a granule. It is to become.
In general, it is known that when an oxidizing aqueous solution of a water-in-oil emulsion explosive is crystallized, the emulsion disintegrates from the crystallized portion, so that the sensitivity and performance as an explosive cannot be maintained. . Even for explosives of this type of use, if it is a local mixing method or a method similar to this, the time from explosive production to use is generally several hours to several days, so it is extremely short, It doesn't matter much. However, explosives can typically last several months, from as long as six months to nearly a year from manufacture to use. Therefore, a granulated or granular water-in-oil emulsion explosive is also required that does not crystallize an aqueous oxidizing agent solution and is stable over time for several months or more. In particular, it is desirable that the explosive is stable so that the properties of the water-in-oil type emulsion explosive do not change for a long period of time so that the explosive can be loaded into a machine.
In addition, when a granulated explosive is stored under a load such as mechanical loading after being stored for a long period of time, the drug may coagulate, the drug may not be loosened, and it may be difficult to use. Therefore, it is desirable that the granular water-in-oil emulsion explosive does not agglomerate even when subjected to a load such as long-term storage, mechanical loading, or the like, or that the agglomerate is easily loosened.
[0007]
[Patent Document 1]
U.S. Pat. No. 3,161,551
[Patent Document 2]
JP-A-7-223888 (page 2-3)
[Patent Document 3]
JP-A-11-278975 (pages 2-3)
[Patent Document 4]
JP 2001-172096 A (pages 2-3)
[Patent Document 5]
JP 2001-206797 A (pages 2-3)
[Non-patent document 1]
"Review Report on Effective Tunneling Technology" Published by Japan Tunneling Technology Association [0008]
[Problems to be solved by the invention]
The present invention provides (1) excellent stability over time, (2) hardly causes deterioration of explosive performance and agglomeration even during long-term storage for about one year, and (3) easy unraveling even when agglomeration occurs. (4) Explosives that can be easily loaded with a loading machine even after long-term storage, and (5) have excellent water resistance and can be suitably used for blasting in water holes The purpose is to provide.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve such problems, and as a result, spraying an anti-adhesive agent on the surface of a water-in-oil type emulsion explosive causes adhesion and agglomeration even when a load is applied to the explosive. It has been found that a difficult water-in-oil emulsion explosive can be obtained, and the present invention has been completed.
[0010]
That is, the present invention
(1) an explosive characterized in that powder having an average particle size of 500 μm or less is attached to the surface of a water-in-oil emulsion explosive;
(2) The explosive according to (1), wherein the amount of the powder used is 0.01 to 10% by weight in the explosive.
(3) The explosive according to the above (1) or (2), wherein the weight per one grain is 0.03 to 5 g.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail. In the present invention, a powder having a specific particle size is attached to the surface of the water-in-oil emulsion explosive particles. Hereinafter, this powder is referred to as an adhesion inhibitor. The anti-adhesion agent used in the present invention is used as a lubricant to improve slipping property between substances and anti-blocking property, and powder having an average particle size of 500 μm or less, preferably an average particle size of 300 μm or less is used. . Specific examples of powders that can be used include metal salts such as calcium carbonate and magnesium carbonate, metal oxides such as silicon oxide and alumina, minerals such as talc and kaolin, glass powder, fatty acid amide and resin hollow. Organic powders such as powders are preferred, and inorganic powders are preferred because they are chemically stable and often do not destroy emulsions.
[0012]
If the amount of the antiadhesive used in the present invention is too small, the effect of preventing adhesion and agglomeration is not sufficient, and if it is too large, the explosive performance may be reduced. Although it cannot be said unconditionally because it varies depending on the specific gravity of the powder used, it is usually 0.01 to 10% by weight, preferably 0.03 to 5% by weight, attached to the explosive of the present invention.
[0013]
The explosive of the present invention can be obtained by adhering the antiadhesive to the surface of a water-in-oil emulsion explosive. The water-in-oil type emulsion explosive is not particularly limited, and for example, a water-in-oil type emulsion explosive containing an oxidizing agent, oils, an emulsifier, and water can be used.
Specific examples of oils contained in the water-in-oil emulsion explosive include petroleum oils such as light oil, kerosene, mineral oil, lubricating oil, heavy oil, paraffin wax, and microcrystalline wax, and the like. Other examples include hydrophobic vegetable oils, vegetable waxes, animal oils, and animal waxes, and these can be used alone or in combination of two or more. Oils are contained in the water-in-oil type emulsion explosive in a proportion of usually 0.1 to 20% by weight, preferably 1 to 10% by weight.
[0014]
Further, in the water-in-oil type emulsion explosive, a part or all of the oils may be replaced with a resin having oil solubility or compatibility with oils. As the characteristics of the resin used, any resin can be used as long as it has a property of being hardened or its viscosity is reduced by heat, and can be injection-molded with a water-in-oil type emulsion explosive, and is generally a thermosetting resin, a thermoplastic resin. Resins, synthetic rubbers and the like can be mentioned. 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 Examples thereof include a resin, a polyimide resin, and a polyethylene resin, but it is preferable that the resin does not react with other components in order to maintain the stability of the water-in-oil emulsion.
[0015]
Further, a thermosetting resin which is liquid or low melting point at room temperature or a thermoplastic resin which is solid at room temperature and shows fluidity when heated is preferable. Specific examples include phenol resin, hydrogenated petroleum resin, polyethylene, polypropylene, polybutene, polyisobutylene, ethylene vinyl acetate copolymer, polybutadiene, styrene butadiene rubber and the like. In addition, since a melted resin is used in the production, the melt flow rate measured based on the “flow test method for thermoplastics” described in JIS K7210 is 10 g / 10 min. As described above, preferably 15 g / 10 min. It is preferable to use the above. In the molded explosive of the present invention, the oil-soluble resin is contained in the explosive in an amount of 0.1 to 10% by weight, preferably 0.1 to 7% by weight. In addition, these resins can be used by mixing as a part of oils contained in an emulsion base composed of an oxidizing agent, oils, and an emulsifier, or mixed as an additive in a water-in-oil emulsion explosive. You can also.
[0016]
As the emulsifier used in the explosive of the present invention, emulsifiers usually used in water-in-oil emulsion explosives, for example, alkali metal stearate, ammonium stearate, calcium stearate, polyoxyethylene ethers, sorbitan fatty acid Examples thereof include esters, sorbitol fatty acid esters, and the like, and these are used as one kind or as a mixture of two or more kinds. In the water-in-oil emulsion explosive of the present invention, the emulsifier is contained in the explosive in an amount of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.
[0017]
The oxidizing agent used in the explosive of the present invention is preferably used as an aqueous solution thereof. Specific examples of oxidizing agents that can be used include ammonium nitrate, alkali metal nitrates such as sodium nitrate, alkaline earth metal nitrates such as calcium nitrate, alkali metal chlorates such as sodium chlorate, and calcium chlorate. Such as alkaline earth metal chlorates, alkali metal perchlorates such as potassium perchlorate, alkaline earth metal perchlorates such as calcium perchlorate, and ammonium perchlorate. Can be used alone or as a mixture. Particularly preferred among these oxidants are ammonium nitrate and sodium nitrate.
[0018]
The aqueous solution of the oxidizing agent used in the present invention may include, if desired, water-soluble amine nitrates such as monomethylamine nitrate, monoethylamine nitrate, hydrazine nitrate and dimethylamine dinitrate; and water-soluble alkanols such as methanolamine nitrate and ethanolamine nitrate. Amine nitrates and water-soluble ethylene glycol mononitrate can be added as auxiliary sensitizers.
[0019]
The content of water in the oxidizing agent aqueous solution used in the present invention is preferably such that the crystallization temperature of the oxidizing agent aqueous solution becomes 30 to 90 ° C. -40% by weight, preferably 7-30% by weight. In the oxidizing agent aqueous solution, a water-soluble organic solvent such as methyl alcohol, ethyl alcohol, formamide, ethylene glycol and glycerin can be used as an auxiliary solvent in order to lower the crystal deposition temperature. In the water-in-oil emulsion explosive of the present invention, the oxidizing agent aqueous solution is contained in the explosive in a range of 50 to 95% by weight.
[0020]
The water-in-oil type emulsion explosive of the present invention can adjust the sensitivity performance of the explosive over a wide range from primer detonation to booster detonation by containing an appropriate amount of micro hollow body. As the minute hollow body, for example, one or a mixture of two or more kinds of inorganic hollow spheres such as glass microballoons and shirasu balloons, and organic hollow spheres such as foamed styrene and resin microballoons are used. Balloons are preferred, and glass microballoons are particularly preferred. The amount of the fine hollow spheres varies over a wide range depending on the use of the explosive, and also depends on the specific gravity of the fine hollow spheres, so cannot be specified unconditionally. Usually, the specific gravity of the explosive is 1.4 g / cc or less, Preferably, the amount used is 1.3 g / cc or less.
[0021]
The water-in-oil emulsion explosive of the present invention may contain metal powders such as aluminum powder and magnesium powder, and organic powders such as wood powder and starch. Depending on the type of the substance to be added and the purpose of the addition, it is usually contained in the explosive in the range of 0.5 to 10% by weight.
[0022]
In the present invention, as a method for producing a water-in-oil emulsion explosive, a method of forming a column by using a generally used extruder, a method of forming a spheroid by a granulator or the like are exemplified.
[0023]
The explosive of the present invention is manufactured, for example, as follows.
That is, the oxidizing agent and, if necessary, the auxiliary sensitizing agent are dissolved in water at about 85 to 95 ° C to obtain an oxidizing agent aqueous solution. Next, the above-mentioned oxidizing agent aqueous solution is gradually added to a mixture of an oil-soluble or oil-compatible resin and an oil and an emulsifier heated to about 85 to 95 ° C. with sufficient stirring. A water-in-oil emulsion explosive is added to the completed water-in-oil emulsion, adding a micro hollow body, and if necessary, other additives, a resin exhibiting oil solubility or compatibility with oils, and mixing with a kneading machine. Get. Then, after the water-in-oil type emulsion explosive is molded by a molding machine such as an extrusion molding machine, powder as an anti-adhesion agent is mixed, and the powder is adhered to the surface of the water-in-oil type emulsion explosive. You can get explosives.
[0024]
In the above-described molding step, the shape of the water-in-oil emulsion explosive is not particularly limited as long as it is easy to handle, and may be spherical, cylindrical, disk-shaped, prismatic, or the like. Molded into any shape by machine.
Further, in the explosive of the present invention, if the molded article is too large, the porosity increases when the explosive is charged into the blast hole, and the explosive charge as the explosive is reduced. Is preferably 0.03 to 5 g.
[0025]
Although the explosive of the present invention is composed of a water-in-oil type emulsion explosive, it has a granular shape and can be easily loaded into the blast hole using a loading machine such as air loading. Further, since the explosive of the present invention has high water resistance and a specific gravity of more than 1, even if the explosive is loaded in a vertical water hole, it can be used without any trouble similarly to a dry hole. Therefore, according to the explosive of the present invention, the explosive performance and long-term stability performance equivalent to that of the conventional water-in-oil emulsion explosive are maintained, and since it can be manufactured with a relatively simple machine, it is safe during manufacture, Further, since it has excellent water resistance, it can be used in water holes, and the residual gas after blasting is less toxic than the ANFO explosive. Furthermore, since the shape is granular, loading by a machine is easy, and the operation and the blasting operation at the time of charging can be simplified and shortened.
[0026]
【Example】
Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
[0027]
Example 1
A 90 ° C. aqueous solution of an oxidizing agent consisting of 74.3 parts by weight of ammonium nitrate, 4.8 parts by weight of sodium nitrate and 10.5 parts by weight of water was mixed with 2.8 parts by weight of microcrystalline wax and 2.8 parts by weight of sorbitan monooleate. The mixture was added to the mixture and mixed well with stirring to obtain a water-in-oil emulsion. 3.8 parts by weight of glass microballoons as fine hollow particles were added thereto and mixed by stirring to obtain a water-in-oil type emulsion explosive. The specific gravity of this emulsion explosive was 1.190 g / cc. This water-in-oil type emulsion explosive is molded by an extruder having a die having a diameter of 8 mm, cut with a knife so as to have a length of 10 mm, and then talc (trade name: DS-34, manufactured by Fuji Talc Kogyo KK) 0 parts by weight were added and mixed to obtain the explosive of the present invention. The specific gravity of the obtained explosive was 1.196 g / cc, and the average weight per grain was 1.0 g.
[0028]
Example 2
A 90 ° C. aqueous solution of an oxidizing agent comprising 74.8 parts by weight of ammonium nitrate, 4.8 parts by weight of sodium nitrate and 10.5 parts by weight of water was mixed with 2.9 parts by weight of microcrystalline wax and 2.9 parts by weight of sorbitan monooleate. The mixture was added to the mixture and mixed well with stirring to obtain a water-in-oil emulsion. 3.8 parts by weight of glass microballoons as fine hollow particles were added thereto and mixed by stirring to obtain a water-in-oil type emulsion explosive. The specific gravity of this emulsion explosive was 1.192 g / cc. This water-in-oil type emulsion explosive is molded by an extruder having a die of 8 mm in diameter, cut with a knife so as to have a length of 10 mm, and then fatty acid amide (trade name: fatty acid amide S, manufactured by Kao Corporation) 0.3 The parts by weight were added and mixed to obtain the explosive of the present invention. The specific gravity of the obtained explosive was 1.193 g / cc, and the average weight per grain was 0.8 g.
[0029]
Example 3
A 90 ° C. aqueous solution of an oxidizing agent consisting of 74.8 parts by weight of ammonium nitrate, 4.8 parts by weight of sodium nitrate and 10.5 parts by weight of water was mixed with 1.9 parts by weight of microcrystalline wax, ethylene vinyl acetate copolymer (Tosoh Corporation) (Trade name: Ultracene 727), 0.8 parts by weight, and 2.9 parts by weight of sorbitan monooleate, and sufficiently stirred and mixed to obtain a water-in-oil emulsion. 3.8 parts by weight of glass microballoons as fine hollow particles were added thereto and mixed by stirring to obtain a water-in-oil type emulsion explosive. The specific gravity of this emulsion explosive was 1.188 g / cc. This water-in-oil emulsion explosive is molded by an extruder having a diameter of 8 mm with a die, cut with a knife so as to have a length of 10 mm, and then 1.0 part by weight of calcium carbonate (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) Was added and mixed to obtain the explosive of the present invention. The specific gravity of the obtained explosive was 1.194 g / cc, and the average weight per grain was 0.9 g.
[0030]
Comparative Example 1
A 90 ° C. aqueous solution of an oxidizing agent consisting of 75.0 parts by weight of ammonium nitrate, 4.8 parts by weight of sodium nitrate and 10.6 parts by weight of water was mixed with 2.9 parts by weight of microcrystalline wax and 2.9 parts by weight of sorbitan monooleate. The mixture was added to the mixture and mixed well with stirring to obtain a water-in-oil emulsion. 3.8 parts by weight of glass microballoons as fine hollow particles were added thereto and mixed by stirring to obtain a water-in-oil type emulsion explosive. This water-in-oil type emulsion explosive was molded with an extruder having a die having a diameter of 8 mm and cut with a knife so as to have a length of 10 mm to obtain a water-in-oil type emulsion explosive for a comparative example.
[0031]
Table 1 shows the composition ratios of the explosives obtained in Example 1, Example 2, Example 3, and Comparative Example 1.
[0032]
Test example 1
A simple load test was performed to examine the adhesion and agglomeration properties of the molded body under load. The test method was as follows. 300 g of explosive for testing was placed in a cylindrical tube having an inner diameter of 80 mm plugged in one end and left in a thermostat set at 35 ° C. while a constant load of 2.34 kgf was continuously applied by a piston from the open end. One week later, it was taken out and the condition of the explosive was evaluated. Further, 20 kg of explosives were actually packaged (put in a bag and stored in a cardboard box) and stored at room temperature for 6 months and 1 year. The state of the explosive after storage for 6 months and 1 year was observed and evaluated. Table 2 shows the test results of Example 1, Example 2, Example 3, and Comparative Example 1.
[0033]
Test example 2
The explosives obtained in Example 1, Example 2, Example 3, and Comparative Example 1 were charged into a steel pipe having an inner diameter of 48 mm, a length of 1 m, and a thickness of 5 mm using an air loading machine, and Nippon Kagaku was used as a booster. A detonation was initiated using 50 g of a water-containing explosive (trade name: ARTEX) manufactured by Yakuhin Co., Ltd., and the detonation speed was measured by the Doitlish method. Further, after the same steel pipe was previously filled with water, each explosive was loaded using an air loading machine in the same manner as described above, and the detonation velocity in the water hole was also measured. Further, as a time-lapse test, the detonation speed of those stored at room temperature for 6 months and 1 year was measured in the drying hole and the water hole by the same method as described above. Table 3 shows the results.
[0034]
[Table 1]

[0035]
[Table 2]

[0036]
In Table 2, "easiness of unraveling" indicates a degree that the bag can be easily loosened by lightly shaking the bag, and a relatively easy degree indicates that the bag can be easily loosened by applying light force by hand.
[0037]
[Table 3]

[0038]
As is evident from the results in Tables 2 and 3, the explosive of the present invention is hard to agglomerate under load, can be loaded by a loading machine, and maintains its performance as an explosive even if stored for about one year. It is clear that there is.
[0039]
【The invention's effect】
The explosive of the present invention is a granular explosive that can be easily loaded into a machine without lowering the explosive performance of the water-in-oil type emulsion explosive, and is further difficult to agglomerate by a load, and can be easily unwound even if agglomerated. It is extremely useful because it has long-term stability over time and can be used in water holes.

Claims (3)

An explosive characterized in that a powder having an average particle size of 500 μm or less is adhered to the surface of a water-in-oil emulsion explosive. The explosive according to claim 1, wherein the amount of the powder used is a proportion occupying 0.01 to 10% by weight in the explosive. The explosive according to claim 1 or 2, wherein the average weight per grain is 0.03 to 5 g.