JP2002137983A - Explosion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an explosive composition without generating excessive solidification even at a high temperature, high humidity in summer as well as less apt to charged at loading into blasting hole and keeping an excellent explosive performance. SOLUTION: The explosion composition is composed of a substrate containing ammonium nitrate containing micro hollow grain, fuel oil and anionic, cationic, or nonionic water-soluble surfactant independently or as a mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to explosive compositions. More particularly, the present invention relates to an ammonium nitrate (ammonium nitrate) explosive composition which is widely used in industrial blasting operations such as quarrying and mining, and which can be directly loaded into perforations of objects to be destroyed.

[0002]

2. Description of the Related Art As industrial explosives used for blasting operations and the like, dynamite, hydrous explosives, nitrate explosives, and nitrate oil explosives (ANFO explosives) are well known. Of these explosives, ANFO explosives are relatively easy to produce, and usually exhibit fluid granularity, so they can be poured directly into perforations or loaded by loaders such as loaders. There are features.

The ANFO explosive is often loaded or poured into the blast hole at a high speed by a pneumatic conveying type loading machine. In such a case, the friction between the explosive particles or the explosive particles and the hose wall, A large amount of static electricity is generated due to friction with the wall of the object to be destroyed. Once the static electricity was generated, the ANFO explosive itself, blast holes, hoses,
There is a danger that this will gradually accumulate in the loader and the like, causing an explosion accident due to discharge to the electric detonator.

As countermeasures against static electricity, use of an anti-static detonator, a charged hose having conductivity, and the like have been performed. Also,
In some cases, oil-soluble antistatic agents (JP-A-55-51794, JP-A-11-147784) are incorporated into ANFO explosives. However, the former is a symptomatic treatment on the premise that a large amount of static electricity is generated, and cannot be said to be a fundamental solution for preventing static electricity. In addition, the latter is effective as a countermeasure against static electricity for ANFO explosives using conventional nitric acid, but it has sufficient anti-static properties against certain types of ANFO explosives using specific nitric acid and exhibiting excellent explosive performance. May not be shown.

[0005]

SUMMARY OF THE INVENTION The use of a specific nitrate,
It is desired to establish a measure for efficiently preventing the charge of ANFO explosives which cannot obtain a sufficient antistatic effect by the conventional antistatic method.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies and have found that by adding a water-soluble surfactant as a compounding component of an ANFO explosive using specific ammonium nitrate. The present inventors have found that an excellent antistatic effect can be obtained without lowering the performance of the ANFO explosive, and have completed the present invention.

That is, the present invention relates to (1) that a substrate contains, alone or in combination, ammonium nitrate containing fine hollow particles, a fuel oil, and an anionic, cationic or nonionic water-soluble surfactant. The explosive composition characterized in that (2) ammonium nitrate having a particle size of not less than 2.36 mm and not more than 0.98 mm is 1.0% by weight, respectively.
The explosive composition according to (1), which is the above and 1.0% by weight or less of porous prill ammonium nitrate, (3) the ammonium nitrate is porous prill ammonium nitrate having a bulk specific gravity of 0.60 to 0.78 (1) to ( The explosive composition according to any one of 2), (4) the ammonium nitrate is a mixture of porous prill ammonium nitrate having an oil absorption of 5 to 20% and a hardness of 0.1 to 10.0%, and a pulverized product thereof ( It relates to the explosive composition according to any one of 1) to (3).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. As the ammonium nitrate used in the explosive composition of the present invention, granular ammonium nitrate (porous prill nitrate) containing fine hollow particles is used, and the fine hollow particles are 1.0 × 10 ⁻⁶ or less based on the porous prill nitrate. 10.0% by weight, preferably 0.0%
It is preferably contained in the porous prill nitrate in the range of 5 to 10.0% by weight. In the explosive composition of the present invention, the fine hollow particles contained in the porous prilled ammonium salt are mainly used as a specific gravity adjuster, and specific examples of the fine hollow particles that can be used include resin microballoons and glass. Natural or synthetic porous substances such as balloons, metal hollow particles, and shirasu balloons, and the like can be used, and these can be used alone or in combination of two or more. In the present invention, resin microballoons are preferred among the above.

Porous prill ammonium salt is 65 to 96% by weight, preferably 75 to 95% by weight, based on the whole explosive composition.
Used in the range. As the porous prill nitrate used in the explosive composition of the present invention, those having a particle size of not less than 2.36 mm and not more than 0.98 mm are each 1.0% by weight.
More preferably, the content is 1.0% by weight or less. Further, the porous prill nitrate used in the explosive composition of the present invention preferably has a bulk specific gravity of 0.60 to 0.78, preferably 0.65 to 0.75. Further, the porous prill nitrate used in the explosive composition of the present invention has an oil absorption of 5 to 20%, preferably 7 to 15%, and a hardness of 0.1 to 10.0%, preferably 0.1 to 10.0%. It is preferably 7.0%, and porous prill ammonium nitrate obtained by pulverizing this is also usable.

In the explosive composition of the present invention, the porous prill ammonium nitrate having the above particle size and the pulverized product thereof can be mixed at an arbitrary ratio. Preferably, the mixing ratio of the pulverized product to the porous prill nitrate is 20 to 80% by weight. The particle size distribution (% by weight) of porous prill ammonium nitrate is obtained by passing a certain amount of porous prill nitrate ammonium through various sieves with different sieves,
It is measured from the weight of the residue on the sieve net for each sieve.

The bulk specific gravity of porous prill nitrate is JIS K
It is measured according to the method specified in -6721. That is, a certain amount of sample porous prill nitrate from a certain height, using a funnel having a damper in the lower part supported by the support rod,
It is measured by weighing the sample porous prill nitrate in the cup after dropping it into the cylindrical cup placed on the support table, removing the ammonium nitrate of the sample porous prill raised on the cup. Specifically, the upper end diameter is 90 mm,
A funnel with a diameter of 15 mm at the lower end and a height of 115 mm was installed so that the distance between the lower end of the funnel and the upper end of the cup having a depth of 80 mm and a volume of 100 cm ³ was 45 mm, and 100 g of sample porous prill nitrate was placed in the funnel. And slide the damper to drop the sample porous prill nitrate into the cup. Carefully take care not to vibrate, and use a spatula to remove the porous prilled ammonium salt of the sample raised on the cup so that it is horizontal at the same height as the top of the cup. The sample porous prill nitrate adhering to the outside of the cup is removed, and the weight of the sample porous prill nitrate in the cup is weighed with an upper direct reading balance. After completing the above measurement, the bulk specific gravity is calculated by the following equation (1).

Bulk specific gravity = sample weight (g) / 100 (cm ³ ) (1)

The oil absorption rate of porous prill nitrate is measured by immersing a fixed amount of sample porous prill nitrate in light oil for a certain period of time, performing suction filtration, and observing the adsorption amount of light oil from the weight difference before and after the test. You. Specifically, 50 g of sample porous prill nitrate is placed in a glass filter (11G-1) having a diameter of 40 mm and a depth of 50 mm, weighed with a direct balance on an upper plate, and set in a vacuum device. Next, 40 ml of light oil is poured into the glass filter, and the mixture is thoroughly stirred with a fine rod to achieve mixed contact between porous prill nitrate and light oil. After standing for 5 minutes, open the external cock attached to the glass filter and let light oil flow naturally for 2 minutes. Subsequently, after suctioning with a vacuum pump for 5 minutes (flow rate: about 30 l / min), the glass filter in which the porous prill nitrate of the sample to which light oil has been adsorbed is weighed with an upper plate direct balance.
Here, the increased amount is the absorbed amount of light oil. After the above measurement, the ratio (%) of the light oil adsorption (g) to 50 g of the original sample porous prill nitrate is indicated as the oil absorption (%). The calculation formula is as shown in the following formula (2).

Oil absorption rate (%) = light oil adsorption (g) / sample 50 (g) × 100 (2)

The oil absorption rate of porous prilled ammonium nitrate mainly depends on the pore volume and effective diameter distributed inside the grains. For example, if the pore volume is large, the space capable of holding light oil inside the grains is reduced. Since it becomes large, the oil absorption rate becomes large.

The hardness of porous prill ammonium nitrate is measured by mechanically pulverizing a fixed amount of porous prill ammonium nitrate under a predetermined condition using a hardness measuring device, and measuring the amount of the pulverized ammonium nitrate. The apparatus used for the measurement is a funnel for sample injection, a flow pipe (inner diameter 16 mm, length 175 mm) connected to the compressed air inlet (inner diameter 4 mm, length 55 mm), and the upper part of these connections and the funnel are connected vertically Sample injection tube (inner diameter 12 mm,
(Length: 52 mm) and a sample pulverizing tube (inner diameter: 50 mm, length: 315 mm) vertically connected to the flow tube.

100 g of porous prill nitrate from which powder has been removed with a 35 mesh sieve is dropped from a funnel into a flow tube through a sample injection tube, and compressed air (4 kg) flowing from an inflow hole.
/ Cm ² ), the sample collides with the inner wall of the pulverizing tube through the flow tube to pulverize the porous prill nitrate. Porous prill ammonium nitrate after sifting is sieved with 35 mesh, and +35 m
The amount of esh (N) is weighed, and the original porous prill nitrate 10
It is expressed as the ratio (%) of the amount of powder to 0 g. The calculation formula is as shown in the following formula (3).

Hardness (%) = 100 (g) −N (g) (3)

As the fuel oil used in the explosive of the present invention, it is preferable to use a fuel oil which is liquid at the time of mixing.
Examples of usable fuels include mineral oils such as light oil and kerosene, vegetable oils, animal oils and the like.

In addition, methyl alcohol,
Alcohols such as ethyl alcohol, waxes such as paraffin wax and microcrystalline wax, and nitro compounds such as dinitrotoluene and dinitroxylene can be used alone or in combination as a fuel oil.
High melting point fuel oils can be used by mixing with porous prill nitrate above the temperature at which it becomes liquid.

The amount of fuel oil used in the explosive of the present invention is usually 2.5 to 25% by weight, preferably 4 to 25% by weight of the entire explosive.
In the range of 10 to 10% by weight.

Examples of the anionic water-soluble surfactant used in the explosive composition of the present invention include carboxylate, sulfonate, sulfate and phosphate. Examples of the cationic water-soluble surfactant include quaternary ammonium salts, primary, secondary, and tertiary amine salts, and pyridinium salts. Further, examples of the nonionic water-soluble surfactant include an alkylamine, an alkylamide, an alkyl ether, and a fatty acid ester.

As a method of adding these surfactants,
Before mixing ammonium nitrate and fuel oil, it can be added to porous prill ammonium nitrate, or can be added to the mixed ANFO explosive. Further, these surfactants can be dissolved in water and added as an aqueous solution.

If the amount of the water-soluble surfactant used in the explosive composition of the present invention is too small, the effect is not sufficient, and if it is too large, the performance of the explosive deteriorates or the explosive solidifies due to the hygroscopicity of ammonium nitrate. (Solidification), there is a possibility of 0.01 to 2.00% by weight, preferably 0.03 to 2.00% by weight based on the entire explosive.
1.00% by weight.

If necessary, the explosive composition of the present invention may contain an oxidizing agent other than porous prill nitrate, for example, potassium nitrate or perchlorate, or a powdered additional fuel such as wood powder or aluminum powder, or other additives. It is possible to add

The explosive composition of the present invention is produced by uniformly mixing the porous prill nitrate with the fuel oil and, if necessary, other additives in a mixer such as a kneader or a rotary mixer. Other mixers can be used as long as they have a function of stirring and mixing.

The explosive composition of the present invention is excellent in non-charging properties, and uses high-temperature and high-temperature properties despite the use of the conventional porous prill nitrate containing fine hollow particles that do not have an antistatic effect.
Since it does not excessively solidify even at high humidity, it has the feature of being excellent in handleability similarly to the conventional ANFO explosive. Further, there is a feature that the water-soluble surfactant added for the purpose of antistatic does not affect the explosion performance, and excellent explosion performance is not impaired.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” indicates “parts by weight”.

Example 1 0.10% by weight of fine hollow particles was contained, and the particle size was 2.36 m.
m and 0.98 mm or less, respectively.
3% by weight and 0.0% by weight, bulk specific gravity 0.68, oil absorption 1
2.0%, 3.0% hardness porous prill nitrate (EXP
AN200: Sasol Chemical Indu
94.0 parts was transferred to a horizontal kneader equipped with a sigma wing at room temperature, 5.7 parts of No. 2 light oil at room temperature, and 0.3 parts of polyoxyethylene lauryl ether (Emulgen 108: manufactured by Kao Corporation). And add 1
The mixture was mixed at a speed of 80 revolutions per minute for 5 minutes to obtain 100 parts of the explosive composition of the present invention.

Example 2 92.5 parts of the same porous prill ammonium nitrate as in Example 1 were transferred to a concrete mixer at room temperature, and the No. 2 light oil at room temperature was 6.5.
Part, lauryl trimethyl ammonium chloride (Coatamine 24P: manufactured by Kao Corporation) 5.0% aqueous solution
0 parts were added and mixed at a speed of 100 rotations per minute for 3 minutes to obtain 100 parts of the explosive composition of the present invention.

Example 3 0.25% by weight of fine hollow particles was contained, and the particle diameter was 2.36 m.
m and 0.98 mm or less, respectively 5.0
Weight% and 0.0 weight%, bulk specific gravity 0.65, oil absorption 1
Porous prill nitrate (E, 1.4% hardness 4.7%)
XPAN100: Sasol Chemical In
80.0 parts and a pulverized product (14.0 parts) were transferred to a concrete mixer at room temperature, and 5.5 parts of No. 2 light oil at room temperature was added.
After mixing at a rotation speed for 5 minutes, 0.5 part of a 20.0% by weight aqueous solution of a dimethyldiallylammonium chloride / acrylamide copolymer (Kayacryl Resin: manufactured by Nippon Kayaku Co., Ltd.) was added, and per minute 1 at 80 rpm
After mixing for 100 minutes, 100 parts of the explosive composition of the present invention was obtained.

Comparative Example 1 The same 94.0 parts of porous prill nitrate as in Example 1 were transferred to a horizontal kneader equipped with a sigma wing at room temperature, 6.0 parts of No. 2 gas oil at room temperature was added, and 100 revolutions per minute were performed. The mixture was mixed at a speed for 3 minutes to obtain 100 parts of a comparative explosive composition (containing no surfactant).

For each of the explosive compositions obtained in Examples and Comparative Examples, the degree of solidification, electrostatic potential and explosion velocity were measured.

The sample used for measuring the degree of solidification has an inner diameter of 50 m.
m, 300 g of each explosive composition in a cylindrical container made of PVC having a height of 300 mm, heated at a temperature of 40 ° C. for 8 hours under a load of 2.7 kg, and then heated at a temperature of 20 ° C. for 16 hours.
Obtained by repeating the time cooling cycle twice.

The degree of solidification is measured by using bolts and nuts so that the rod moves only vertically in a column installed on a stand that does not move even if a load is applied to the end of the rod having a length of 500 mm. The above-described sample was placed at a position 100 mm from the end, a load was gradually applied to the side opposite to the fixed end, and the load was measured by reading the load at which the shape of the sample collapsed. Therefore, it is evaluated that the larger the measured value is, the more solidified it is.

The electrostatic potential was measured by placing a policyt on an aluminum spout having a length of 1820 mm inclined at 45 °, flowing out 500 g of each explosive at a rate of 100 g / sec from a hopper attached to the upper end of the spout. A current-collecting potential measuring instrument (KS-52) having a sensor fixed at a distance of 100 mm perpendicular to the back of the spout through a hole of 60 mm in diameter provided at a position of 700 mm from.
(Type 5: manufactured by Kasuga Electric Co., Ltd.) by reading the electrostatic potential generated in the policy. The above is based on the standard of the Pharmaceutical Society of Japan (ES-81).

The measurement of the explosion speed is performed according to the standard of the Pharmaceutical Society of Japan (ES-
41 (1)).

Table 1 shows the measurement test results of the solidification degree, electrostatic potential and explosion velocity of each explosive.

Table 1 Solidification degree (kg) Electrostatic potential (-kV) Explosion velocity (m / sec) Example 1 3.6 9 3190 Example 2 3.8 10 3180 Example 3 3.5 8 3250 Comparative example 1 14.0 100 3200

As is clear from Table 1, the degree of solidification is very strong in Comparative Example 1, whereas Examples 1 to 3 are not solidified. Regarding the electric potential, the excellent non-charging property in Examples 1 to 3 is apparent as compared with the comparative example. As is clear from Examples 1 to 3, the explosion velocity has no negative influence due to the addition of each surfactant.

[0041]

According to the present invention, an explosive composition having excellent antistatic properties and explosive performance and having characteristics of not causing excessive solidification even at high temperature and high humidity can be obtained.

Claims (4)

[Claims] An explosive composition comprising, in a substrate, ammonium nitrate containing fine hollow particles, a fuel oil, and an anionic, cationic or nonionic water-soluble surfactant alone or in combination. . 2. The explosive according to claim 1, wherein the ammonium nitrate having a particle size of 2.36 mm or more and 0.98 mm or less is 1.0% by weight or more and 1.0% by weight or less of porous prill ammonium nitrate. Composition. 3. The method according to claim 1, wherein the ammonium nitrate has a bulk specific gravity of 0.60 to 0.60.
The explosive composition according to any one of claims 1 to 2, which is 0.78 porous prill ammonium nitrate. 4. The method according to claim 1, wherein the ammonium nitrate is a mixture of porous prill ammonium nitrate having an oil absorption of 5 to 20% and a hardness of 0.1 to 10.0%, and a crushed product thereof. An explosive composition as described.