JP2001048689A - Granular explosive powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the adhesion to double bags, metal containers, or the like, and to improve production work efficiency and the safety at the time of loading by coating the surfaces of porous particles essentially consisting of ammonium nitrate with an emulsified mixture consisting of an oxidizing agent, oil agent, water and emulsifier at specific ratios. SOLUTION: This granular explosive powder is prepared by coating the surfaces of the porous particles essentially consisting of ammonium nitrate with the emulsified mixture containing the oxidizing agent having a weight ratio regulated to <=9.0 to >=1.0 and the oil agent together with the water and the emulsifier. The oil agent and the oxidizing agent are microcrystalline wax, or the like, and ammonium nitrate, or the like, used for, for example, the emulsion explosive powder. The porous particles essentially consisting of ammonium nitrate are, for example, purill ammonium nitrate, or the like, and the emulsifier is a surfactant, or the like, normally used for the emulsion explosive powder. The weight ratio of the oxidizing agent and the oil agent is preferably <=9.0: >=1.0 to >=1.0: <=9.0. The emulsified mixture has a low ignition property, plays the role of fuel and acts to impart water resistance to the ammonium nitrate particles by being applied to the ammonium nitrate particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to blasting, crushing, excavation and the like of industrial explosives. The invention relates more particularly to improvements in industrial explosives.

[0002]

2. Description of the Related Art Explosives generally used as industrial explosives are hydrous explosives such as dynamite, emulsion explosives and slurry explosives, and nitrous acid explosives (ANFO). Dynamite is formed into a cylinder at the stage of manufacturing, and there is a cartridge type wound with paper one by one, and is consumed in that state. Wet explosives are also available in paper roll and vinyl tube cartridge types. Depending on the formulation, hydrous explosives have fluidity in the normal explosive operating temperature range.They are called bulk type and are shipped in heavy bags or metal containers while maintaining fluidity, and are blasted using a mono pump or the like. Some are loaded and consumed. An ammonium nitrate explosive is a granular explosive, and is a bulk explosive charged by an ANFO loader or the like using compressed air. Cartridge-type explosives are loaded one by one into the blast holes, which takes a long time to work and poses a safety problem because workers have to approach the face where there is unstable rock. . On the other hand, bulk-type explosives are charged mechanically, so that relatively quick and safe operation is possible.

[0003]

Many types of bulk type water-containing explosives have extremely high adhesiveness, and are referred to as "adhesive residues". The explosives adhere to heavy bags for transportation and storage, metal containers of loading machines, and the like. There is a problem that tends to remain. It is often difficult to completely remove the residual drug by using a spatula in order to recover it, especially in the loading hose and in the bent or right-angled metal containers. It is. After all, there is no other way but to wash away with water with a suitable surfactant over time. Furthermore, it may adhere to the body surface or the work clothes of the worker and make the worker feel uncomfortable. In addition, if it adheres to the hand, it becomes slippery, which often impairs safety and work efficiency. The nitrate explosive is a bulk type explosive,
Because it is a granular explosive, there is no need to worry about residual drugs, but it has poor water resistance and is less powerful than hydrous explosives.
In addition, it is not always suitable for blasting tunnel construction due to problems such as bad post gas. From such a problem,
Recently, a granular explosive (Chinese Patent 1137507) in which an emulsion explosive is coated on the surface of an ammonium nitrate explosive particle has been studied. The explosives were made by adding water resistance by covering a non-water resistant nitric acid oil explosive with a water resistant emulsion explosive, and the workability was relatively improved as a granular explosive. In order to produce a powerful explosive,
First of all, two explosives must be manufactured: a nitrate oil explosive and an emulsion explosive. In addition, when mixing these two explosives, they must be heated to near the emulsification temperature, and there is often a danger that gas oil evaporates. Furthermore, the produced explosive requires careful stirring for about 8 hours to prevent agglomeration, and the manufacturing process is very complicated with danger.

[0004]

According to the present invention, the surface of porous particles mainly composed of ammonium nitrate is coated with an emulsified mixture comprising an oil agent, an oxidizing agent, water and an emulsifier. Weight ratio of the agent to the oil agent is 9.0 or less to 1.
It is a granular explosive characterized by being 0 or more. A preferred embodiment of the present invention is an explosive granulated including at least one porous particle mainly composed of ammonium nitrate.

[0005] Here, the oil agent and the oxidizing agent are described in "Energy Material Handbook, P.95-P.98, Kyoritsu Shuppan (1.
999) ". That is, it refers to oil agents such as microcrystalline wax and paraffin wax used for emulsion explosives, and oxidizing agents such as ammonium nitrate, nitrate of alkali metal, and nitrate of alkaline earth metal. Further, the porous particles mainly composed of ammonium nitrate are described in, for example, "Energy Material Handbook", p. 93-P. 9
4 means prill nitrate and the like. Further, the emulsifier refers to a usual one used for an emulsion explosive as a surfactant or the like.

In one preferred embodiment of the present invention, the composition of the emulsified mixture is such that the weight ratio of the oxidizing agent to the oiling agent is 9.0 or less to 1.0 or more, and more preferably 9.
The ratio is from 1.0 to 9.0, more preferably from 2.0 to 8.0, and more preferably from 2.0 to 8.0. Further, an emulsifier is added to promote and stabilize emulsification by an emulsifier. The amount of water to be added is determined by safety, production method, and the like. For example, in order to lower the dissolution temperature of the oxidizing agent at the time of emulsification, water needs to be at least 3% by weight based on the oxidizing agent. Also, when mixing the emulsified mixture and porous particles containing ammonium nitrate as a main component, for example, when adding the emulsion mixture to prill ammonium nitrate by spraying,
If the viscosity is large, the spray does not result in a sprayed state. Therefore, the amount of water must be up to 19 times the total weight of the oxidizing agent, oil agent and emulsifier. With these compositions, the emulsified mixture itself has low or no explosive properties.

In the present invention, the emulsified mixture has a negative oxygen balance and plays a role of fuel for ammonium nitrate particles.
It has a function of imparting water resistance by being coated with ammonium nitrate particles as an oxidizing agent. In addition, the emulsified compound has low or no explosive property and is safe in production. The oil agent which is a component of the emulsified mixture is solid at ordinary temperature and preferably has a melting point lower than the temperature at which the reaction with the oxidizing agent starts, and preferably has a melting point in the range of 50 ° C to 140 ° C, more preferably It has a melting point in the range of 60 ° C to 120 ° C. At that time, once the emulsified mixture is coated and granulated with particles mainly composed of ammonium nitrate as an explosive, the agglomeration of the explosive particles is prevented, and the adhesion to the transport bag, the metal container of the loading machine, etc. is prevented. Can come off.

The porous particles mainly composed of ammonium nitrate may be composed of only ammonium nitrate, or may be composed of ammonium nitrate as a main component and containing inorganic salts such as sodium nitrate, potassium nitrate, calcium nitrate and potassium sulfate. Good. A liquid fuel such as light oil or a nitro compound can be added to the porous particles containing ammonium nitrate as a main component for the purpose of improving the reactivity. But,
Since the emulsified mixture is coated on the surface of prilled nitrate as a fuel, the value must be lower than 6% of the amount of light oil normally added in, for example, an ammonium nitrate explosive in consideration of oxygen balance and production safety. For example, "Blaster
s'Handbook, 17th edition,
p. 89, International Society
y of Explosives Engineer
s, Inc. , Cleveland, 1998 "describes that when 6% by weight of light oil is added to prilled nitrate, it has a maximum theoretical energy and a maximum theoretical detonation speed, and the actual detonation speed also increases from 6% by weight to 8% by weight. Has a value.
In addition, the sensitivity related to the detonation property is from 2% by weight to
There is a description that the sensitivity is high in the range of weight%. Therefore,
In the present invention, when light oil is added to porous particles containing ammonium nitrate as a main component, the content is preferably 2% by weight or less, and more preferably 1% or less.

The explosive of the present invention is provided with a detonating property and a stable detonation property, for example, by a void in prilled nitrate. Therefore, in that case, it is desirable to prevent the emulsified mixture from entering the inside of the prilled ammonium nitrate and reducing the voids of the prilled ammonium nitrate during mixing and granulation of the emulsified mixture and prilled ammonium nitrate. For example, when a large amount of water is added and the emulsified mixture easily penetrates into the interior of the porous particles mainly composed of ammonium nitrate, the emulsified mixture is gradually composed mainly of ammonium nitrate while evaporating water with hot air or the like. It is desirable to add, mix and granulate the porous particles. When the viscosity of the emulsified mixture is high and the emulsified mixture does not penetrate into the particles mainly composed of ammonium nitrate, for example, immediately after emulsification, the mixture is cooled to room temperature or the temperature at which the emulsified mixture is cooled and hardly mixed. What is necessary is just to mix and granulate. Granulation can be performed using, for example, a rolling granulator, a fluidized bed granulator, or a composite granulator. In a tumbling granulator, for example, prill nitrate as core particles is put into a rotating pan to cause a rotating motion. The emulsified mixture is gradually added thereto. This emulsified mixture adheres to the surface of the rolling prill nitrate, and is granulated by rotating together with the prill nitrate. Alternatively, the emulsified mixture and prill nitrate are mixed in advance, the mixture is adjusted to an appropriate size, and then the mixture is poured into a rotating pan and granulated while being rolled. By changing the manufacturing conditions, the explosive of the present invention obtains one explosive particle by coating one particle of prill nitrate with the emulsified mixture, or collects several particles to several tens of particles of prill ammonium nitrate by coating the emulsified mixture. Can be used as a single explosive particle. For example, when gradually adding the emulsified mixture to the rotating prill nitrate in a rotating pan, reduce the amount of the emulsified mixture added per unit time,
When the exercise of prill nitrate is increased, one explosive particle consisting of a small number of prill nitrate particles is obtained. In addition, the explosive particle size may be adjusted by, for example, the temperature at the time of mixing or the viscosity of the emulsified mixture.

In the explosive of the present invention, glass microballoons, organic hollow particles and the like can be added to the emulsified mixture as a specific gravity adjusting agent. The explosive of the present invention may contain an anti-blocking agent such as carbon black, silica or talc so as not to cause aggregation or adhesion during granulation or after production. Further, an antistatic substance such as carbon black or a surfactant can be added for the purpose of improving and adding the antistatic property. Further, metal powder such as aluminum powder and magnesium powder can be added as an energy improver.

[0011]

The present invention will be described in more detail with reference to Examples and Comparative Examples. The evaluation methods performed in Examples and Comparative Examples are shown below.

[0012]

[Evaluation method 1] Heavy bag adhesion confirmation test In order to evaluate the state of adhesion of granular explosives to heavy bags, explosives 5
kg was packed in a 15 liter nylon bag, sealed, packed in cardboard, and stored for one week. Thereafter, the explosive was taken out of the nylon bag and transferred to a 30 cm × 30 cm × 30 cm stainless steel container equipped with a conductive hose having an inner diameter of 19 mmφ at the bottom. Thereafter, the state of attachment of the explosive to the nylon bag was confirmed.

[0013]

[Evaluation method 2] Stainless steel container adhesion confirmation test The stainless steel container containing the explosive of Evaluation method 1 was pressurized, and all the explosive was discharged from the conductive hose. Thereafter, the state of attachment of the explosive to the stainless steel container was confirmed. Further, when explosives were attached to the stainless steel container or hose, the explosives were flushed with water. If the explosives could not be washed out with water, the explosives were washed with a detergent such as a surfactant.

[0014]

[Evaluation method 3] Water resistance test
12mm holes randomly opened steel pipe (inner diameter 35mm
× 350 mm in length, one of which is sealed), the open end of the steel pipe was closed with 30 g of No. 2 Enoki dynamite, and immersed in water for one hour. After that, it was taken out of the water, and a No. 6 electric detonator was attached to the dynamite to check whether it would detonate.

[0015]

EXAMPLE 1 58% by weight of ammonium nitrate, 7% by weight of sodium nitrate, 4% by weight of water, 9% by weight of an emulsifier (trade name: EXCEL 300 manufactured by Kao Corporation), an oil agent (manufactured by Nippon Seiro Co., Ltd.)
(Trade name: Hi-Mic 2095) 22% by weight was emulsified using an emulsifier. Immediately after the emulsification, 2 kg of the emulsified mixture and 5 kg of prilled ammonium nitrate at room temperature are rapidly mixed in an aluminum pan, and the mixture is extruded through a mesh having an aperture of 3.35 mm and rotated at 40 rpm. p. m. And put into a rotating stainless steel pan. Cooling was performed while feeding dry air (75 cubic meters / hour) at 25 ° C. into a stainless steel pan to obtain a granular explosive of 1 to 5 mm. Also,
During granulation, 60 g of talc was added to prevent aggregation. The obtained explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0016]

Example 2 Ammonium nitrate 58% by weight, sodium nitrate 7% by weight, water 4% by weight, emulsifier (manufactured by Kao Corporation-trade name: Exel 300) 9% by weight, oil agent (Nippon Seiro-
(Trade name: Hi-Mic 2095) 22% by weight was emulsified using an emulsifier. Immediately after the emulsification, 2 kg of this emulsified mixture was mixed with 100 g of glass microballoons, and further rapidly mixed with 5 kg of prilled ammonium nitrate at room temperature in an aluminum pan. The mixture was extruded through a mesh having an opening of 3.35 mm and rotated at 40 rpm. p. m. And put into a rotating stainless steel pan. Cooling was performed while feeding dry air (75 cubic meters / hour) at 25 ° C. into a stainless steel pan to obtain a granular explosive of 1 to 5 mm. During granulation, 60 g of talc was added to prevent aggregation. The obtained explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0017]

Example 3 Ammonium nitrate 35% by weight, sodium nitrate 4% by weight, water 40% by weight, emulsifier (manufactured by Kao Corporation)
6% by weight of trade name: Exel 300) and 15% by weight of an oil agent (manufactured by Nippon Seiwa Co., Ltd .; trade name: Hi-Mic 2095) were emulsified using an emulsifier. 3.5 kg of this emulsified mixture is
It was added to 5 kg of prill nitrate rotating in a stainless steel rotating pan (rotation speed 40 rpm) at an addition amount of g / min to 180 g / min to obtain a granular explosive of 1 mm to 5 mm. The temperature of the emulsified mixture added during granulation is 80 ° C., and dry air at 100 ° C. (100 cubic meters / hour)
Prill nitrate from 80 ° C to 100
C. In addition, talc 60 is used to prevent agglomeration during granulation.
g was added. The obtained explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0018]

Example 4 7.8% by weight of ammonium nitrate, 0.7% by weight of sodium nitrate, 87% by weight of water, 1% by weight of an emulsifier (trade name: Emulgen 106, manufactured by Kao Corporation) (Product name: Hi-Mic2095) 3.5
% By weight was emulsified using an emulsifier. This emulsified mixture 16
kg was added to 5 kg of rotating prill nitrate in a stainless steel rotating pan (rotation speed 40 rpm) at an addition amount of 60 g / min to 130 g / min, and 1 mm
To obtain a 5 mm granular explosive. The temperature of the emulsified mixture added during granulation is 90 ° C.
0 p.m./hour) into the bread and prill nitrate 90
C. to 100.degree. During granulation, 60 g of talc was added to prevent aggregation. The obtained explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0019]

Example 5 Ammonium nitrate 58% by weight, sodium nitrate 7% by weight, water 4% by weight, emulsifier (manufactured by Kao Corporation-trade name: Exel 300) 9% by weight, oil agent (manufactured by Nippon Seiro)
(Trade name: Hi-Mic 2095) 22% by weight was emulsified using an emulsifier. Immediately after the emulsification, 2 kg of the emulsified mixture was mixed with 100 g of glass microballoons, and further rapidly mixed with 5 kg of prilled ammonium nitrate at room temperature previously mixed with 1.5% of light oil in an aluminum pan. The mixture was extruded through a 3.35 mm mesh and the number of rotations was 40.
r. p. m. And put into a rotating stainless steel pan. Dry air at 25 ° C (7
(5 cubic meters / hour) while cooling to obtain 1 to 5 mm granular explosives. In addition, talc 6 is used to prevent agglomeration during granulation.
0 g was added. The obtained explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0020]

Comparative Example 1 Ammonium nitrate 70% by weight, sodium nitrate 10% by weight, water 13% by weight, emulsifier (manufactured by Kao Corporation-trade name: Exel 300) 2% by weight, oil agent (manufactured by Nippon Seiwa-trade name: Hi) -Mic 2095) and 5% by weight of glass microballoons (outer part) were emulsified by an emulsifier to obtain an emulsion explosive. The explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0021]

COMPARATIVE EXAMPLE 2 94% by weight of prill nitrate and 6% by weight of light oil were mixed in an aluminum pan to obtain an ammonium nitrate explosive. The explosive was evaluated by the above evaluation method. Table 1 shows the results.

[0022]

[Table 1]

Heavy bag adhesion confirmation test No adhesion: ○ Adhesion required, cleaning with washing liquid: × Stainless steel container adhesion confirmation test No adhesion: ○ Adhesion, cleaning required with cleaning liquid: × Water resistance test Explosion possible: ○ Explosion Impossible: ×

From Table 1, none of the explosives of the examples adhered to the heavy bags and the stainless steel containers. In addition, it was able to detonate in the water resistance test. The explosive of Comparative Example 1 adhered to heavy bags, stainless steel containers, etc., and required a cleaning liquid for cleaning, which was a difficult operation. The explosive of Comparative Example 2 did not adhere to heavy bags, stainless steel containers, etc., but did not have water resistance. From the above, it has been found that the granular explosive of the present invention does not adhere to heavy bags, metal containers, and the like, and can improve work efficiency, safety at the time of charging, problems of residual drug adhered, and the like.

[0025]

According to the present invention, a granular explosive is obtained by coating an emulsified mixture comprising an oil agent, an oxidizing agent and water on the surface of particles such as prilled nitrate, so that it does not adhere to heavy bags, metal containers, etc. Efficiency, safety at the time of charging, and problems of residual drug adhesion can be improved.

Claims (3)

[Claims] 1. The surface of a porous particle mainly composed of ammonium nitrate is coated with an emulsified mixture comprising an oil agent, an oxidizing agent, water and an emulsifier, and the composition of the emulsified mixture is such that the weight ratio of the oxidizing agent to the oil agent is 9%. A granular explosive characterized in that the ratio is not more than 0.0 to not less than 1.0. 2. The explosive according to claim 1, wherein the composition of the emulsified mixture has a weight ratio of the oxidizing agent to the oil agent of 1.0 or more to 9.0 or less and 1.0 or more to 9.0 or less. 3. The explosive according to claim 1, wherein the porous particles mainly composed of ammonium nitrate contain a fuel.