JP2668578B2 - Pressurized explosive - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure-formed explosive used for industrial blasting operations such as quarrying, civil engineering, mining, and the like.

(Prior Art) A typical example of an explosive comprising a mixture of an oxidizing agent and a fuel substance is an ammonium nitrate explosive in which ammonium nitrate and an oil agent (for example, light oil) are mixed. This explosive cannot be detonated with a single detonator, so an explosive is used for detonation, but since it is a relatively insensitive and fluid granular material, it must be poured directly into the blast borehole. And the entire borehole can be densely filled. Further, since the unit price of the product is lower than other explosives, it is widely used as an industrial explosive.

On the other hand, there are ammon explosives and carlits as explosives in which a mixture of an oxidizing agent and a fuel substance contains metal powder such as aluminum or silicon iron. The properties of these explosives are powdery,
Usually, it is used in the form of a cartridge filled in a medicine package.
These explosives are sensitive enough to be detonated with a single primer,
Also, since it contains metal powder, it explodes at a higher detonation speed than the ammonium nitrate oil explosive. Ammonia explosives are used in relatively large boreholes with a diameter of 60 mm or more, and ammon explosives and cartridges can be used in small boreholes of 50 mm or less.

(Problems to be Solved by the Invention) A mixed explosive consisting of an oxidant and a fuel substance, which is the most typical explosive, is an ammonium nitrate explosive, which is widely used because it is safe to handle and has a low unit price. The main component is ammonium nitrate, which has the drawback that when it is poured directly into the borehole and charged, it is easily dissolved in the borehole where water is present, desensitized, and does not explode. Therefore, its use is limited in the case of boreholes with spring water and open pit sites in rainy weather. As a countermeasure, a method is used in which the ammonium nitrate oil explosive is filled in a water-resistant plastic medicine barrel and used. However, if the medicine package is damaged and damaged by the wall of the borehole and water penetrates inside, the ammonium nitrate is easily dissolved. Further, since the bulk specific gravity of the entire medicine cartridge is smaller than that of water, in order to sink the medicine into the water hole, it is necessary to take measures such as weighting the medicine medicine, and the loading operation becomes extremely complicated.

In the case of Ammon explosive, since it is powdery, it is difficult to pour it into the borehole, and since the main component is ammonium nitrate, the property of dissolving in water is similar to that of ammonium nitrate oil explosive.
Normally, a water-proofed cartridge is filled, and the waterproofness can be maintained by the cartridge. However, if the cartridge is damaged, the ammonium nitrate therein is dissolved. Further, when the vial is filled with the medicine barrel, a void is generated between the borehole and the medicine barrel, resulting in waste of explosion energy. This is a similar problem with cartridge type explosives.

In the case of cartrit, ammonium perchlorate alone or a mixture of ammonium perchlorate and nitrate is used as the oxidant component. Ammonium perchlorate is less hygroscopic than ammonium nitrate, but is still soluble in water. Therefore, like Ammon explosive, it is impossible to directly pour it into the water hole and use it as a cartridge.
As with Ammon explosives, it will waste explosive energy.

Therefore, in such a site, a water-resistant explosive is used. As an explosive that can be poured into water-resistant explosives, there are TNT explosives. TNT is a high-density, high-performance explosive that easily deposits in water holes. However, TNT itself is explosives, and must be handled with care, and the unit price Is high, which causes an increase in blast cost. In addition, slurry explosives and dynamite are used as water-resistant explosives. These explosives are cartridge-type explosives individually mounted in cartridges, and can be poured directly into boreholes as in the case of nitrous acid oil explosives. Can not. In addition, the unit price is higher than that of the nitrate oil explosive, and the blasting cost is increased.

Various studies have been carried out to improve the water resistance of the nitrite oil explosives. One of the methods is to add a special dry component to the nitrate oil explosives and mix them. However, this method does not allow direct loading into the water hole,
It must be drained from the borehole and then loaded. Then, when spring water is generated from cracks in the bedrock after loading, a special dry component interacts with water to cause gelation and prevent water from entering the explosive. Therefore, the water resistance performance of this type of nitrate oil explosive is hardly inherently water resistant.

As described above, it has been a major issue to improve a safe and inexpensive explosive comprising a mixture of an oxidizing agent and a fuel substance so that the explosive can be directly poured into a water hole and used.

(Means for Solving the Problems) The present inventors have conducted intensive studies so that an explosive composed of a mixture of an oxidizer and a fuel substance can be directly poured into a water hole, and as a result, a mixture of an oxidizer and a fuel substance was obtained. It has been found that an explosive excellent in water resistance and capable of being directly filled into a borehole can be obtained by press-molding a predetermined amount. That is, the present invention relates to a press-molded explosive characterized by press-molding a mixture of a fuel substance as an oxidant.

The oxidizing agent used in the present invention includes ammonium nitrate, alkali metal nitrates, alkaline earth metal nitrates, alkali metal chlorates, alkaline earth metal chlorates, alkali metal perchlorates, alkaline earth metal perchlorates. Chlorates and ammonium perchlorate may be used alone or in combination.

Among the oxidizing agents used in the present invention, the most economical and widely used one is ammonium nitrate having various shapes such as powdery, granular and porous prill. Above all, porous prill nitrate has a void inside, so that it comes into close contact with the fuel substance and has a higher detonation sensitivity than other nitrites. Furthermore, even among the porous prilled ammonium nitrate, the particle size is
If you use fine porous prilled ammonium nitrate of 1.4 mm or less,
Explosion performance is improved, which is the most preferable.

In the present invention, the oxidizing agent is used for the entire pressure molded explosive.
It is preferably used in the range of 85 to 98% by weight.

The waxes used in the present invention are preferably hydrocarbon-containing fuel substances that are solid at room temperature. For example, petroleum waxes such as paraffin wax and microcrystalline wax, animal and plant waxes such as wool wax and carnauba wax, and mineral waxes such as montan wax can be used alone or as a mixture of two or more. It is also possible to use a petroleum oil such as light oil, kerosene, or mineral oil which is liquid at room temperature, or a hydrophobic animal or plant oil such as mineral oil in combination with the above-mentioned waxes, in a range where the solid is formed at room temperature. is there.

When the aforementioned waxes are used in combination with resins, for example, petroleum resins, polyisobutylene resins, butadiene resins, polyethylene washes, ethylene vinyl acetate copolymers, etc., the pressure molding obtained by pressure molding is used. The physical strength against impact of explosives and the water resistance are improved, which is particularly advantageous.

Petroleum resin used in the present invention is a resin obtained by polymerizing a fraction obtained by naphtha cracking process, C ₅ obtained by polymerizing C ₅ fraction
In the system petroleum resin, C ₅ C ₉ copolymer petroleum resin C ₉ petroleum resins obtained by polymerizing C ₉ fractions, both fractions are copolymerized, the molecular weight of 600
~ 2500 are preferred.

The polyisobutylene resin used in the present invention is a polymer of high-purity isobucilene and preferably has a molecular weight of 5,000 to 140,000.

The butadiene resin used in the present invention has the general formula [CH ₂
= CH-CH = CH ₂ ] butadiene as a main component, leaving a double bond at the 1,2 bond and / or the 1,4 bond, and the terminal part is [-H], (-COOH) or
[-CH ₂ -CH ₂ OH] and has a molecular weight of 500 to 2
00000 butadiene resin is preferred.

The polyethylene wax used in the present invention is a polymer of ethylene represented by the general formula [CH ₂ = CH ₂ ] and preferably has a molecular weight of 1,000 to 10,000.

Ethylene vinyl acetate copolymer used in the present invention,
A copolymer of ethylene represented by the general formula [CH ₂ = CH ₂ ] and vinyl acetate represented by the general formula [CH ₃ COOH = CH ₂ ], having a melt index of 2 to 500, and vinyl acetate An ethylene vinyl acetate copolymer having a content of 5% by weight to 50% by weight is preferable.

In addition to the waxes of the present invention, or a mixture of waxes and resins, it is also possible to use nitro compounds such as dinitrotoluene, dinitroxylene and dinitronaphthalene.

In the present invention, it is preferable to use waxes or a mixture of waxes and resins in a range of 2 to 15% by weight based on the entire pressure-molded explosive.

In the present invention, it is sufficient to use waxes or a mixture of waxes and resins as the fuel substance, but it is also possible to use metal powder to further increase explosive energy. .

In the present invention, a resin, an aluminum powder, a magnesium powder, an iron sulfide powder, a silicon iron powder, or the like is used if desired. The most commonly used is aluminum powder, which is classified into flake aluminum and atomized aluminum depending on the shape, but can be used alone or in a mixture.

In the present invention, the powder is preferably used in the range of 0 to 5% by weight based on the entire pressure-molded explosive.

The pressure molding of the present invention is to put a predetermined amount of a mixture of an oxidizing agent and a fuel substance into a mold and pressurize to form an aggregate of the mixture particles. The shape of the molded product is particularly limited. is not. Depending on the shape of the mold, it can be formed into an arbitrary shape such as a cylinder, a disk, a sphere, a prism, and the like.

The weight of one piece of the pressure-molded explosive of the present invention can be arbitrarily selected, but it is in the range of 1 g to 30 g from the viewpoint of loadability into the borehole and the initiation performance of the loaded pressure-molded explosive as a whole. Things are desirable. In addition, the density of one pressure-molded explosive of the present invention is in the range of 1.0 g / cc to 1.30 g / cc in order to maintain sedimentation in water holes and appropriate detonation performance.

The press-molded explosive obtained by press-molding the mixture of the oxidizing agent and the fuel substance of the present invention, in particular, mainly the mixture of ammonium nitrate and wax, has excellent water resistance as compared with the conventional nitrate oil explosive. As shown in the figure, the present inventors further found that by coating a hydrophobic substance on the outer surface of each pressure-molded explosive, the water resistance was dramatically improved and the physical strength against impact was improved. I found something to improve.

As the hydrophobic substance for coating used in the present invention, generally, a substance having a water-repellent property can be used. Petroleum oils such as mineral oil and heavy oil, paraffin wax,
Petroleum waxes such as microcrystalline wax and petrolatum; synthetic oils such as silicone oil; animal waxes such as wool wax and beeswax; plant waxes such as carnauba wax and wood wax; higher fatty acids such as myristic acid and stearic acid. , Higher alcohols such as cetyl alcohol and stearyl alcohol, petroleum resins, polyethylene waxes, butadiene resins, polyisobutylene resins, ethylene vinyl acetate copolymers, resins such as epoxy resins, or a mixture of two or more resins are preferable. used.

Among the hydrophobic substances for coating, waxes such as paraffin wax and microcrystalline wax which exhibit a solid state at ordinary temperature, resins alone or as a mixture, or a mixture of the above-mentioned hydrophobic substances, are solid at ordinary temperature. Is used, the waterproof effect is further improved.

As a method of coating a hydrophobic substance on the outer surface of a pressure-formed explosive, there are methods of impregnating a hydrophobic substance heated and melted, a solution diluted with a suitable solvent with a hydrophobic substance, or a method of coating a molten hydrophobic substance. This is performed by spraying a hydrophobic substance diluted in a suitable substance or a suitable solvent.

The amount of the hydrophobic substance for coating used in the present invention is desirably in the range of 0.01 g to 0.1 g per gram of the pressure-formed explosive.

(Operation) The present inventors press-mold a mixed explosive composed of an oxidizing agent and a wax, or a mixture of a wax and a resin, or further apply a hydrophobic explosive to the outer surface of the pressure-molded explosive. It has been found that by coating a substance, an explosive that can be directly poured into a water hole and can exhibit sufficient water resistance can be obtained. Further, as a fuel substance, a mixture obtained by adding the powder is press-molded, and further coated with a hydrophobic substance, so that it can be poured into water holes, exhibit water resistance, and be an explosive having excellent explosive energy. It is the one that found out.

(Examples) The present invention will be described in detail below with reference to examples.

Reference Example 1. Porous prill nitrate (Sumitomo Chemical Co., Ltd.) 94% by weight
Then, 6 wt% of paraffin wax (130 ° F paraffin, manufactured by Nippon Seiro Co., Ltd.) heated and dissolved at 90 ° C. was added thereto and mixed well to obtain an explosive mixture. 10 g of this mixture was weighed, placed in a cylindrical mold, and pressurized so that the density of one pressure-formed explosive became 1.07 g / cc to obtain a pressure-formed explosive.

Reference example 2. Paraffin wax (Nippon Seiwa Co., Ltd. 130 ° F paraffin) heated and dissolved at 90 ° C in 94% by weight of fine porous prilled sodium nitrate (Sumitomo Chemical Co., Ltd.) with a particle size of 1.4 mm or less.
6% by weight was added and mixed well to obtain a granular explosive mixture.
10 g of this mixture was weighed and placed in a cylindrical mold, and pressurized to 1.07 g / cc outside the density of one pressure-formed explosive to obtain a pressure-formed explosive.

Reference Example 3. A paraffin wax (Nippon Seiwa Co., Ltd., 130 ° F) preliminarily heated and melted at 90 ° C in 94% by weight of fine porous prill nitrate having a particle size of 1.4 mm or less (Sumitomo Chemical Industries, Ltd.). Paraffin) (5.4% by weight) and ethylene vinyl acetate copolymer (Mitsui Polychemical Co., Ltd., Evaflex # 250) 0.6% by weight were added and sufficiently mixed at 90 ° C. to obtain a granular explosive mixture. 10 g of this mixture was weighed, placed in a cylindrical mold, and pressurized so that the density of one pressure-formed explosive became 1.07 g / cc, thereby obtaining a pressure-formed explosive.

Example 1. A pressure-formed explosive was obtained by the same composition and the same production method as in Reference Example 2. Further, a hydrophobic substance composed of paraffin wax, petrolatum and petroleum resin was coated on the outer surface to obtain a pressure-molded explosive.

Example 2 A pressure-molded explosive was obtained by the same composition and the same production method as in Reference Example 3. Further, a hydrophobic substance composed of paraffin wax, patrolatum and petroleum resin was coated on the outer surface to obtain a pressure-formed explosive.

Example 3 A preliminarily heated and dissolved mixture of 86.5% by weight of fine porous prill nitrate having a particle size of 1.4 mm or less (Sumitomo Chemical Co., Ltd.) and 5.0% by weight of potassium nitrate (Wako Pure Chemical Industries, Ltd.) Dinitrotoluene (Wako Pure Chemical Industries, Ltd.) 3.0% by weight
Was added and mixed well. Furthermore, 0.2% by weight of light oil (Nippon Oil Co., Ltd. No. 2 light oil) which was previously heated and mixed was mixed, 4.9% by weight of paraffin wax (130 ° F paraffin of Nippon Seirowa Co., Ltd.), and polyethylene wax (Sanyo Chemical Industries, Ltd. A mixture of 0.2% by weight of wax 151P) and butadiene resin (RB-810, Nippon Synthetic Rubber Co., Ltd.) was added and mixed well at 90 ° C. to obtain a granular explosive mixture. 25 g of this mixture is weighed and placed in a cylindrical formwork, and the density of one pressurized explosive
Pressurization was carried out so as to obtain 1.03 g / cc to obtain a pressurized molded explosive. Further, a hydrophobic substance composed of paraffin wax, microcrystalline wax and ethylene-vinyl acetate copolymer was coated on the outer surface to obtain a pressure-formed explosive.

Example 4 5.8% by weight of paraffin wax (Nippon Seiwa Co., Ltd. 130 ° F paraffin) heated and dissolved in 93.2% by weight of fine porous prilled ammonium nitrate (Sumitomo Chemical Co., Ltd.) having a particle size of 1.4 mm or less was added. , 90 ° C. After cooling to room temperature, flake aluminum (Toyo Aluminum Co., Ltd., PO10
0) 1.0 wt% was added and mixed well to obtain a granular explosive mixture. 7 g of this mixture was weighed, placed in a cylindrical mold, and pressurized so that the density of one pressure-formed explosive became 1.14 g / cc to obtain a pressure-formed explosive. Further, a paraffin wax, petrolatum, and a hydrophobic substance composed of petroleum resin were coated on the outer surface to obtain a pressure-molded explosive.

Example 5 Paraffin wax (Nippon Seiwa Co., Ltd. 130 ° F paraffin) 5.2 pre-heated and melt-mixed with 93.2% by weight of fine porous prilled sodium nitrate (Sumitomo Chemical Co., Ltd.) having a particle size of 1.4 mm or less. A mixture of 0.6% by weight and 0.6% by weight of an ethylene-vinyl acetate copolymer (Mitsui Polychemical Co., Ltd., Evaflex # 250) was added, and the mixture was thoroughly mixed at 90 ° C. After cooling to room temperature, flake aluminum (Toyo Aluminum Co., Ltd., PO10
0) 1.0% by weight was added and mixed well to obtain a granular explosive mixture. 7 g of this mixture was weighed, placed in a cylindrical mold, and pressurized so that the density of one pressure-formed explosive became 1.14 g / cc to obtain a pressure-formed explosive. Further, a hydrophobic substance made of paraffin wax was coated on the outer surface to obtain a pressure-molded explosive.

Example 6. Fine porous prill having a particle diameter of 1.4 mm or less 73.5% by weight (Sumitomo Chemical Co., Ltd.), 10.0% by weight of powdery nitrate (Ube Industries, Ltd.) and potassium nitrate (Wako Pure Chemical Industries, Ltd.) 4.2% by weight of paraffin wax (130 ° F paraffin), microcrystalline wax (1.0% by weight of Nippon Seiwa Co., Ltd. HiMiC1045), which was previously dissolved and mixed in a 8.4% by weight mixture. Resin (Toho Petroleum Resin Co., Ltd. Toho Hi-Resin # 75) 0.2% by weight, polyethylene wax (Sanyo Chemical Co., Ltd. Sun Wax 15)
A mixture of 0.1% by weight of 1P) and 0.1% by weight of a polyisobutylene resin (Vistanex MML-80, manufactured by Esso Chemical Co., Ltd.) was added and thoroughly mixed at 90 ° C. Then, 2.5% by weight of atomized aluminum (VA-500, Yamaishi Metal Co., Ltd.) was added and mixed well to obtain a granular explosive mixture. 10 g of this mixture was weighed, placed in a cylindrical mold, and pressurized so that the density of one pressure-formed explosive became 1.25 g / cc, thereby obtaining a pressure-formed explosive. Further, an outer surface was coated with a hydrophobic substance composed of paraffin wax to obtain a pressure-formed explosive.

Comparative Example 1. Porous prill nitrate (94.0% by weight of Sumitomo Chemical Co., Ltd.)
To the above, 6.0 wt% of light oil (Nippon Oil Co., Ltd. No. 2 light oil) was added and mixed well to obtain a granular explosive mixture.

Comparative Example 2 A granular explosive composition was obtained with the same composition and the same manufacturing method as in Reference Example 1.

Comparative Example 3 A granular explosive composition was obtained by the same composition and the same manufacturing method as in Reference Example 3.

Comparative Example 4. Paraffin wax (Nippon Seiwa Co., Ltd. 130 ° F paraffin) 5.2 pre-melted and mixed in 93.2% by weight of fine porous prilled sodium nitrate (Sumitomo Chemical Co., Ltd.) having a particle size of 1.4 mm or less. A mixture of 0.6% by weight of ethylene vinyl acetate copolymer (Evaflex # 250, Mitsui Polychemicals Co., Ltd.) was added, and the mixture was sufficiently mixed at 90 ° C. After cooling to room temperature, flaky aluminum (PO100, Toyo Aluminum Co., Ltd.)
1.0 wt% was added and mixed well to obtain a granular explosive composition.

Table 1 summarizes the compositions of Examples 1 to 6 and Comparative Examples 1 to 4.

For all of these compositions, a water resistance test and a physical strength test were carried out for pressure-formed explosives, and a comparative study was conducted.

In the water resistance performance test, a simulated water hole was prepared by putting water into a steel pipe having an inner diameter of 65 mm and a length of 1000 mm, and Examples 1 to 6 were formed in the steel pipe.
And the granular explosives of Comparative Examples 1 to 4 were respectively filled, and the explosion performance corresponding to the elapsed time after filling was measured.
As a method of examining the explosive performance, the explosive charge has a diameter of 60 mm, weight
Using 200 g of pentrite, detonate from the upper part of the steel pipe, and according to the explosion speed test method of Daulish, 15 cm from the bottom of the steel pipe.
The average explosion velocity between two points of 5 cm was measured.

Height 1 as a method of examining the physical strength of pressurized explosives
From a position of m or 3 m in height, the pressure-molded explosive was allowed to fall naturally onto a concrete floor surface, and the degree of destruction of the pressure-formed explosive (destruction rate) was examined. Destruction rate than the weight W ₁ of the largest debris after the drop and the weight W ₀ of the pressing explosive before falling, was determined by calculating the following equation.

The results are summarized in Table 2.

(Effect of the Invention) Since the surface of the pressure-formed explosive of the present invention is coated with a hydrophobic substance, it has high physical strength and excellent water resistance. Further, the pressure-molded explosive of the present invention is characterized in that the explosive velocity is almost unchanged even in water.

Claims (3)

(57) [Claims] An oxidizing agent and a wax as a fuel substance having a density of from 1.0 g / cc to 1.30 g / cc, and a weight of one granule is from 1 to 30 g. A pressure-formed explosive formed by coating an agent with a hydrophobic substance. 2. The press-molded explosive according to claim 1, wherein the oxidizing agent is porous prill nitrate having a particle size of 1.4 mm or less. 3. The fuel material according to claim 1, further comprising a resin and / or one or more materials selected from the group consisting of aluminum powder, magnesium powder, iron sulfide powder, and silicon iron powder. Item 3. A pressure-formed explosive according to item 1 or 2.