JPS6028795B2 - Ammonium explosive and its manufacturing method - Google Patents

Description

Detailed Description of the Invention The present invention relates to an ammonium explosive consisting of porous ammonium nitrate and a combustible material, and involves mixing the porous ammonium nitrate with the combustible material while pulverizing it, and specifying the ingredients, composition, and particle size of the raw material. The present invention relates to a method for safely producing ammonium explosives with good performance.

In general, explosives containing ammonium nitrate as a main component, such as ammonium nitrate oil explosives (hereinafter abbreviated as AN-FO), have tended to be used quite frequently in recent years as safe and inexpensive explosives.

However, while this explosive is safe and inexpensive, it has limited performance and is not suitable for various severe usage conditions. For example, due to the disadvantages of low detonation sensitivity and poor detonation propagation, it is necessary to use other explosives that are easy to detonate as a booster in actual use, and if the blast hole is a water hole because it is not water resistant. Since it is not possible to use bare drugs, for example, so-called piece products individually packaged with water-resistant thin plastic film are used, but in this case, they cannot be tightly loaded with a loading machine, so the potency of nukamari is small and hard rocks are used. In some cases, sufficient blasting effect may not be obtained. Furthermore, although water-containing explosives (slurry explosives) are superior to AN-FO in terms of safety and detonability, they must be considerably more expensive due to their raw materials and other considerations. Further, although conventional ammonium explosives have exposure properties comparable to those of hydrous explosives, they are expensive due to the complexity of their manufacture and have not been able to become the mainstream of industrial explosives.

The present invention was obtained as a result of intensive research to address the problems of conventional explosives mainly composed of ammonium nitrate as described above, and is a highly sensitive, high-power explosive that can be easily, safely, and inexpensively produced. The purpose is to provide ammonium explosives.

That is, the ammonium explosive of the present invention and its manufacturing method are characterized in that porous sprill ammonium nitrate and a combustible material are pulverized and mixed using a pulverizer such as a ball mill.

The type of ammonium nitrate used in the present invention may be any porous sprill ammonium nitrate used as a raw material for AN-FO, but powdered ammonium nitrate for industrial use or granular ammonium nitrate for fertilizers is not acceptable.

As will be explained later in Examples, explosives using ammonium nitrate other than porous sprill ammonium nitrate did not provide detonator detonation sensitivity. Taking this reason into consideration, it is thought that porous sprill ammonium nitrate maintains its porous nature even when crushed, and generates a hot spot when detonated. The particle size of the porous sprill ammonium nitrate also has a large effect on the detonation sensitivity. That is,
The most preferable detonation sensitivity can be obtained by setting the particle size to 50-60% passing through 80 mesh and 5% or less passing through 200 mesh. The detonation sensitivity range is exceeded. Furthermore, simply mixing pulverized porous sprill ammonium nitrate and combustible material cannot maintain the initial performance because each component is likely to separate during long-term storage.

Moreover, the performance of the finished explosive also varies, which is undesirable. In the present invention, porous sprill ammonium nitrate and combustible material are crushed and mixed together using a crusher such as a ball mill, thereby bringing the ammonium nitrate and combustible material into close contact, thereby eliminating variations, preventing deterioration over time, and achieving desired results. This is to ensure stable performance. In addition, the combustible materials used in the present invention are preferably dinitrotoluene (hereinafter abbreviated as DNT) and wood flour, but some or all of them may be replaced with other conventionally known nitro compounds such as trinitrotoluene, dinitrotoluene, dinitrotoluene, etc. It is also possible to replace it with tonaphthalene etc.
Such cases are also included within the scope of the present invention.

The method of melting DNT and mixing it with wood flour to obtain a combustible material, which is one of the features of the present invention, is intended to simplify the handling of DNT, which is solidified, and to improve the performance of the explosive. This was obtained as a result of intensive research.

That is, by keeping DNT in a heated and molten state and mixing it with wood flour, the mixture of DNT and wood flour can be handled as granules or powder, and the ratio of wood flour can be increased. This is what I did. Even if the solidified DNT is pulverized in advance and mixed with water powder as in the conventional method, a mixture with almost the same properties can be obtained.
Disadvantages include the fact that it takes a considerable amount of effort to pulverize NT, and if the proportion of wood powder is increased, the tentative specific gravity of the resulting explosive may be too low and the detonator detonation sensitivity may not be obtained. There is. However, according to this method, even if the ratio of wood powder to DNT is increased to 50%, it will not have any negative effect on the performance of the explosive, and the solidified DN
Advantages such as eliminating the need to pulverize T in advance can be obtained. Furthermore, the particle size of the wood flour mixed into the molten DNT is one of the important requirements for realizing the present invention.

That is, unless ultrafine wood powder is used, which has a particle size of 95% or more that passes through 100 meshes, the explosive will not exhibit the desired performance. DNT mixtures mixed with relatively coarse wood flour tend to reconsolidate, albeit weakly, during long-term storage.
The reason for this is not clear, but as a result of observing the DNT wood flour mixture under a microscope, the following points were inferred. Most of the molten DNT mixed with wood flour is precipitated as fine needle-like crystals on the surface of the wood flour after being absorbed by the wood flour. In the DNT mixed with DNT, few needle-shaped crystals were observed, and it was observed that the DNT was just coating the wood powder.

Therefore, DNT mixed with coarse wood flour has a tendency to re-solidify, and when mixed with porous sprill ammonium nitrate, it seems that the expected performance cannot be obtained because there are few needle-shaped crystals. The ammonium explosive obtained by the method of the present invention has sufficient practical sensitivity and power using only the above-mentioned raw materials, but the sensitivity and power can be further increased by adding a certain amount of aluminum powder to it. The aluminum powder added at this time may be atomized or flaked; however, if the particle size is too coarse, it will reduce the strength of the explosive, which is undesirable, and if it is too fine, aluminum dust will accumulate, which is undesirable for the work environment.
This has negative effects such as unnecessarily increasing the sensitivity of the explosive. Therefore, in the case of atomized aluminum powder, it is optimal to have a particle size of about 96% that passes through 350 mesh.
In the case of flake aluminum powder, it is appropriate to have a particle size in which about 73% of the powder passes through 200 mesh. The most desirable material is dedusted aluminum powder that has been treated with dustproof treatment such as Teflon coating. Hereinafter, the characteristics and effects of the ammonium explosive of the present invention will be specifically explained using Examples and Comparative Examples. All percentages in each example are by weight. In Example 1, porous sprill ammonium nitrate and a combustible material obtained by mixing separately prepared DNT with molten wood flour were ground and mixed in a wooden ball mill for 2 minutes.

In Examples 2 to 5, aluminum powder was added to the above drug and mixed for an additional 5 minutes. In Comparative Example 1, porous sprill ammonium nitrate was ground to the desired particle size in a Shiji pot mill.
This was mixed with the same DNT wood flour mixture as in the example for 20 minutes using a mold mixer. Comparative Example 2 was obtained by mixing powdered ammonium nitrate in the same manner as in Example 2. In Comparative Example 3, atomized aluminum having a relatively coarse particle size was mixed in the same manner as in Example 3. In Comparative Example 4, wood flour having a relatively coarse particle size was mixed in the same manner as in Example 4. Comparative Example 5 is a mixture in the same manner as in Example 5 using a combustible material obtained by pulverizing solidified DNT and mixing it with wood flour in equal amounts. Comparative Example 6 uses porous sprill ammonium nitrate and D prepared separately.
A combustible material obtained by melting NT and mixing it with wood flour was ground and mixed in a wooden ball mill, and then aluminum powder was added and mixed for an additional 5 minutes. Comparative example 7 is
Porous brill ammonium nitrate and a combustible material obtained by melting DNT prepared separately and mixing it with wood flour were pulverized and mixed in a wooden ball mill for 3 minutes, and aluminum powder was added thereto and mixed for an additional 5 minutes. In the table, the detonation sensitivity test was carried out by inserting a No. 6 electric detonator into one end of a polyethylene cartridge with a thickness of 0.08 ribs and a diameter of 25 mm filled with 10 female charges of the sample explosive, and inserting a No. 6 electric detonator into the other end. After ignition, it was determined that the sample explosive had completely burned out when the conductor wire ignited.

The denominator is the number of tests and the numerator is the number of complete explosions. A sample drug is placed in a truncated cone-shaped paper tube with a thickness of 0.25 ribs, with a length of 70 sides, a large diameter of 34 ribs, and a small diameter of 6 ribs, and an electric snow tube is inserted from the Oyo side. This is a test to find out the diameter of the part where Fujidoro interrupted after detonating it.

The higher this value is 4.0, the better the explosive conductivity of the sample drug can be judged. Tests below Bakuen test are JISK4
810 (Explosives Performance Test Method).

As is clear from Example 1 and Comparative Example 1, the desired performance cannot be obtained by simply pulverizing porous sprill ammonium nitrate and simply mixing it with a combustible material.

Further, when comparing Example 2 and Comparative Example 2, it is clear that when powdered ammonium nitrate is used, the desired performance cannot be obtained even if all other conditions are the same. Example 3 and Comparative Example 3
It is clear that aluminum powder, which is added for the purpose of increasing sensitivity and power, will conversely decrease both sensitivity and power if its particle size is relatively coarse.

When using relatively coarse wood flour from Example 4 and Comparative Example 4,
It is clear that the resulting explosive has better performance than an explosive using fine wood powder.

Moreover, when comparing Examples 4 and 5, it can be seen that even if the amount of wood powder increases to some extent, there is no significant difference in the properties and performance of the explosive. Further, when compared with Comparative Example 5, it can be seen that when DNT is pre-pulverized and mixed with thick flour, the properties and various performances deteriorate as the amount of wood flour increases. Further, from Example 4 and Comparative Examples 6 and 7, it is clear that the desired detonator detonation sensitivity cannot be obtained when the particle size of the porous sprill ammonium nitrate is relatively coarse or fine. As explained above, the ammonium explosive of the present invention and the method for producing the same consist of porous ammonium nitrate of a specific particle size, dinitrotoluene, and a combustible material prepared by adding wood powder or aluminum powder to the same. Since this is mixed with the above-mentioned combustible material, it is easy and safe to manufacture, and moreover, it is possible to provide a highly sensitive and highly powerful ammonium explosive at a low cost.

Claims (1)

[Scope of Claims] 1. A porous sprill ammonium nitrate and a combustible material, the particle size of the porous sprill ammonium nitrate is 50 to 60% passing through an 80 mesh, and 5% or less passing a 200 mesh, and the combustible material is dinitrotoluene and wood flour. , or an ammonium explosive characterized by having aluminum powder added thereto. 2 Weight ratio of 5:5 to 7 to molten dinitrotoluene
The ammonium explosive according to claim 1, characterized in that the ammonium explosive contains 9 to 14% by weight of a powdery combustible material with a particle size of 3 mm or less obtained by mixing 3 mm wood powder. 3. The ammonium explosive according to claim 1, wherein the aluminum powder is an atomized aluminum powder having a 350 mesh passing rate of 96% or more, and the content thereof is 6% by weight or less. 4. The ammonium explosive according to claim 1, wherein the aluminum powder is flake aluminum powder having a pass through 200 mesh of 73% or more, and the content thereof is 1% by weight or less. 5 The above wood flour passes through 100 meshes and has a moisture content of 4 or more when 95% or more
．． Claim 1 characterized in that it is 5% or less
Ammonium explosive according to paragraph 2 or paragraph 2. 6. A method for producing an ammonium explosive, which comprises mixing porous sprill ammonium nitrate with a combustible material while pulverizing it. 7. The method for producing an ammonium explosive according to claim 6, wherein the combustible material is a granular material obtained by melting dinitrotoluene and mixing wood flour with it.